92 matches found in 40 documents. Search time: 0.004 seconds. |
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Score: 2.00 | Title: The C terminus of AvrXa10 can be replaced by the transcriptional activation domain of VP16 from the herpes simplex virus .
| Author: Zhu W Yang B Wills N Johnson LB White FF .
| Journal: Plant Cell Citation: V : 11 ( 9 ) P : 1665-74 Year: 1999 Type: ARTICLE | Literature: oryza Field: abstract Doc ID: pub10488234 Accession (PMID): 10488234 | Abstract: The avirulence gene avrXa10 of Xanthomonas oryzae pv oryzae directs the elicitation of resistance in a gene-for-gene manner in rice lines carrying the resistance gene Xa10 .
We have localized a transcriptional activator domain in the C terminus of AvrXa10 by using amino acid replacement mutagenesis .
One mutant , with replacements at three hydrophobic amino acid residues in the C-terminal domain , was defective for transcriptional activation in yeast and avirulence activity in rice .
The activation domain from the herpes virus protein VP16 restored the ability of the bacteria expressing the hybrid protein to elicit a resistance reaction .
Elicitation was specific for Xa10 , and the reaction had the hallmarks of the response to AvrXa10 .
The results indicate that a domain with the properties of a transcriptional activator plays a critical role in AvrXa10 function .
The results also indicate that the protein has the potential to interact with the plant transcriptional program , although a role for the domain in the stability or conformation of the protein in the plant can not be excluded .
In a broader sense , the transcriptional activation domain of avrXa10 may represent a prokaryotic version of the acidic transcriptional activation domain , which heretofore has been found exclusively in eukaryotes . | Matching Sentences: [ Sen. 1, subscore: 1.00 ]: The avirulence gene avrXa10 of Xanthomonas oryzae pv oryzae directs the elicitation of resistance in a gene-for-gene manner in rice lines carrying the resistance gene Xa10 . We have localized a transcriptional activator domain in the C terminus of AvrXa10 by using amino acid replacement mutagenesis . One mutant , with replacements at three hydrophobic amino acid residues in the C-terminal domain , was defective for transcriptional activation in yeast and avirulence activity in rice . The activation domain from the herpes virus protein VP16 restored the ability of the bacteria expressing the hybrid protein to elicit a resistance reaction . Elicitation was specific for Xa10 , and the reaction had the hallmarks of the response to AvrXa10 . [ Sen. 5, subscore: 1.00 ]: The avirulence gene avrXa10 of Xanthomonas oryzae pv oryzae directs the elicitation of resistance in a gene-for-gene manner in rice lines carrying the resistance gene Xa10 . We have localized a transcriptional activator domain in the C terminus of AvrXa10 by using amino acid replacement mutagenesis . One mutant , with replacements at three hydrophobic amino acid residues in the C-terminal domain , was defective for transcriptional activation in yeast and avirulence activity in rice . The activation domain from the herpes virus protein VP16 restored the ability of the bacteria expressing the hybrid protein to elicit a resistance reaction . Elicitation was specific for Xa10 , and the reaction had the hallmarks of the response to AvrXa10 . The results indicate that a domain with the properties of a transcriptional activator plays a critical role in AvrXa10 function . The results also indicate that the protein has the potential to interact with the plant transcriptional program , although a role for the domain in the stability or conformation of the protein in the plant can not be excluded . In a broader sense , the transcriptional activation domain of avrXa10 may represent a prokaryotic version of the acidic transcriptional activation domain , which heretofore has been found exclusively in eukaryotes .
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Score: 1.00 | Title: Plant disease resistance genes encode members of an ancient and diverse protein family within the nucleotide-binding superfamily .
| Author: Meyers BC Dickerman AW Michelmore RW Sivaramakrishnan S Sobral BW Young ND .
| Journal: Plant J Citation: V : 20 ( 3 ) P : 317-32 Year: 1999 Type: ARTICLE | Literature: oryza Field: abstract Doc ID: pub10571892 Accession (PMID): 10571892 | Abstract: The nucleotide binding site ( NBS ) is a characteristic domain of many plant resistance gene products .
An increasing number of NBS-encoding sequences are being identified through gene cloning , PCR amplification with degenerate primers , and genome sequencing projects .
The NBS domain was analyzed from 14 known plant resistance genes and more than 400 homologs , representing 26 genera of monocotyledonous , dicotyle-donous and one coniferous species .
Two distinct groups of diverse sequences were identified , indicating divergence during evolution and an ancient origin for these sequences .
One group was comprised of sequences encoding an N-terminal domain with Toll/Interleukin-1 receptor homology ( TIR ) , including the known resistance genes , N , M , L6 , RPP1 and RPP5 .
Surprisingly , this group was entirely absent from monocot species in searches of both random genomic sequences and large collections of ESTs .
A second group contained monocot and dicot sequences , including the known resistance genes , RPS2 , RPM1 , I2 , Mi , Dm3 , Pi-B , Xa1 , RPP8 , RPS5 and Prf .
Amino acid signatures in the conserved motifs comprising the NBS domain clearly distinguished these two groups .
The Arabidopsis genome is estimated to contain approximately 200 genes that encode related NBS motifs ; TIR sequences were more abundant and outnumber non-TIR sequences threefold .
The Arabidopsis NBS sequences currently in the databases are located in approximately 21 genomic clusters and 14 isolated loci .
NBS-encoding sequences may be more prevalent in rice .
The wide distribution of these sequences in the plant kingdom and their prevalence in the Arabidopsis and rice genomes indicate that they are ancient , diverse and common in plants .
Sequence inferences suggest that these genes encode a novel class of nucleotide-binding proteins .
| Matching Sentences: [ Sen. 7, subscore: 1.00 ]: The NBS domain was analyzed from 14 known plant resistance genes and more than 400 homologs , representing 26 genera of monocotyledonous , dicotyle-donous and one coniferous species . Two distinct groups of diverse sequences were identified , indicating divergence during evolution and an ancient origin for these sequences . One group was comprised of sequences encoding an N-terminal domain with Toll/Interleukin-1 receptor homology ( TIR ) , including the known resistance genes , N , M , L6 , RPP1 and RPP5 . Surprisingly , this group was entirely absent from monocot species in searches of both random genomic sequences and large collections of ESTs . A second group contained monocot and dicot sequences , including the known resistance genes , RPS2 , RPM1 , I2 , Mi , Dm3 , Pi-B , Xa1 , RPP8 , RPS5 and Prf . Amino acid signatures in the conserved motifs comprising the NBS domain clearly distinguished these two groups . The Arabidopsis genome is estimated to contain approximately 200 genes that encode related NBS motifs ; TIR sequences were more abundant and outnumber non-TIR sequences threefold . The Arabidopsis NBS sequences currently in the databases are located in approximately 21 genomic clusters and 14 isolated loci . NBS-encoding sequences may be more prevalent in rice .
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Score: 2.00 | Title: Predicting durability of a disease resistance gene based on an assessment of the fitness loss and epidemiological consequences of avirulence gene mutation .
| Author: Vera Cruz CM Bai J Ona I Leung H Nelson RJ Mew TW Leach JE .
| Journal: Proc . Natl . Acad . Sci . USA Citation: V : 97 ( 25 ) P : 13500-5 Year: 2000 Type: ARTICLE | Literature: oryza Field: abstract Doc ID: pub11095723 Accession (PMID): 11095723 | Abstract: Durability of plant disease resistance ( R ) genes may be predicted if the cost of pathogen adaptation to overcome resistance is understood .
Adaptation of the bacterial blight pathogen , Xanthomonas oryzae pv . oryzae ( Xoo ) , to virulence in rice is the result of the loss of pathogen avirulence gene function , but little is known about its effect on aggressiveness under field conditions .
We evaluated the cost in pathogenic fitness ( aggressiveness and persistence ) associated with adaptation of Xoo to virulence on near-isogenic rice lines with single R genes ( Xa7 , Xa10 , and Xa4 ) at two field sites endemic for bacterial blight .
Disease severity was high in all 3 years on all lines except the line with Xa7 .
Of two Xoo lineages ( groups of strains inferred to be clonally related based on DNA fingerprinting ) detected , one , lineage C , dominated the pathogen population at both sites .
All Xoo strains were virulent to Xa4 , whereas only lineage C strains were virulent to Xa10 .
Only a few strains of lineage C were virulent to Xa7 .
Adaptation to virulence on Xa7 occurred through at least four different pathways and was associated with a reduction in aggressiveness .
Loss of avirulence and reduced aggressiveness were associated with mutations at the 3 terminus of the avrXa7 allele .
Strains most aggressive to Xa7 were not detected after the second year , suggesting they were less persistent than less aggressive strains .
These experiments support the prediction that Xa7 would be a durable R gene because of a fitness penalty in Xoo associated with adaptation to Xa7 . | Matching Sentences: [ Sen. 3, subscore: 1.00 ]: Durability of plant disease resistance ( R ) genes may be predicted if the cost of pathogen adaptation to overcome resistance is understood . Adaptation of the bacterial blight pathogen , Xanthomonas oryzae pv . oryzae ( Xoo ) , to virulence in rice is the result of the loss of pathogen avirulence gene function , but little is known about its effect on aggressiveness under field conditions . We evaluated the cost in pathogenic fitness ( aggressiveness and persistence ) associated with adaptation of Xoo to virulence on near-isogenic rice lines with single R genes ( Xa7 , Xa10 , and Xa4 ) at two field sites endemic for bacterial blight . Disease severity was high in all 3 years on all lines except the line with Xa7 . Of two Xoo lineages ( groups of strains inferred to be clonally related based on DNA fingerprinting ) detected , one , lineage C , dominated the pathogen population at both sites . All Xoo strains were virulent to Xa4 , whereas only lineage C strains were virulent to Xa10 . Only a few strains of lineage C were virulent to Xa7 . [ Sen. 6, subscore: 1.00 ]: Adaptation of the bacterial blight pathogen , Xanthomonas oryzae pv . oryzae ( Xoo ) , to virulence in rice is the result of the loss of pathogen avirulence gene function , but little is known about its effect on aggressiveness under field conditions . We evaluated the cost in pathogenic fitness ( aggressiveness and persistence ) associated with adaptation of Xoo to virulence on near-isogenic rice lines with single R genes ( Xa7 , Xa10 , and Xa4 ) at two field sites endemic for bacterial blight . Disease severity was high in all 3 years on all lines except the line with Xa7 . Of two Xoo lineages ( groups of strains inferred to be clonally related based on DNA fingerprinting ) detected , one , lineage C , dominated the pathogen population at both sites . All Xoo strains were virulent to Xa4 , whereas only lineage C strains were virulent to Xa10 . Only a few strains of lineage C were virulent to Xa7 . Adaptation to virulence on Xa7 occurred through at least four different pathways and was associated with a reduction in aggressiveness . Loss of avirulence and reduced aggressiveness were associated with mutations at the 3 terminus of the avrXa7 allele . Strains most aggressive to Xa7 were not detected after the second year , suggesting they were less persistent than less aggressive strains .
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Score: 2.00 | Title: [ Construction of a deep coverage rice BAC library and identification of clones associated with disease-resistant genes ] | Author: Wang WM Jiang GH Wang SQ Zhu LH Zhai WX .
| Journal: Yi Chuan Xue Bao Citation: V : 28 ( 2 ) P : 120-8 Year: Type: ARTICLE | Literature: oryza Field: abstract Doc ID: pub11233255 Accession (PMID): 11233255 | Abstract: A BAC library for IRBB56 , an accession pyramiding Xa4 , xa5 and xa13 three bacterial blight resistance genes , was constructed .
The library contains 55 , 296 clones with an average insert size of 132 kb .
Based on a haploid genome size of 450 Mb , the coverage of the library was about 14 genome equivalents that make it one of the most comprehensive BAC libraries available in rice and provide 99 . 99% possibility to isolate any interested rice genes or sequences in the library .
To determine the representation of organelle DNA homologues in the library , the library was screened with three different chloroplast genes and four mitochondrial genes , respectively .
Results from this screening showed that less than 1% of clones in the library contain organelle genomic DNA homologues .
Then , DNA markers on three different chromosomes linked to Xa4 , xa5 , and xa13 , and a PCR fragment of rice UROD gene , were used to screen the library resulting in a range of 11-106 hits that will promote the isolation of these genes .
The deep coverage and the large insert size of the library will facilitate physical mapping , isolation , and cloning of rice genes . | Matching Sentences: [ Sen. 1, subscore: 1.00 ]: A BAC library for IRBB56 , an accession pyramiding Xa4 , xa5 and xa13 three bacterial blight resistance genes , was constructed . The library contains 55 , 296 clones with an average insert size of 132 kb . Based on a haploid genome size of 450 Mb , the coverage of the library was about 14 genome equivalents that make it one of the most comprehensive BAC libraries available in rice and provide 99 . 99% possibility to isolate any interested rice genes or sequences in the library . To determine the representation of organelle DNA homologues in the library , the library was screened with three different chloroplast genes and four mitochondrial genes , respectively . Results from this screening showed that less than 1% of clones in the library contain organelle genomic DNA homologues . [ Sen. 6, subscore: 1.00 ]: The library contains 55 , 296 clones with an average insert size of 132 kb . Based on a haploid genome size of 450 Mb , the coverage of the library was about 14 genome equivalents that make it one of the most comprehensive BAC libraries available in rice and provide 99 . 99% possibility to isolate any interested rice genes or sequences in the library . To determine the representation of organelle DNA homologues in the library , the library was screened with three different chloroplast genes and four mitochondrial genes , respectively . Results from this screening showed that less than 1% of clones in the library contain organelle genomic DNA homologues . Then , DNA markers on three different chromosomes linked to Xa4 , xa5 , and xa13 , and a PCR fragment of rice UROD gene , were used to screen the library resulting in a range of 11-106 hits that will promote the isolation of these genes . The deep coverage and the large insert size of the library will facilitate physical mapping , isolation , and cloning of rice genes .
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Score: 2.00 | Title: Marker assisted selection of bacterial blight resistance genes in rice .
| Author: Davierwala AP Reddy AP Lagu MD Ranjekar PK Gupta VS .
| Journal: Biochem . Genet . Citation: V : 39 ( 7-8 ) P : 261-78 Year: 2001 Type: ARTICLE | Literature: oryza Field: abstract Doc ID: pub11590832 Accession (PMID): 11590832 | Abstract: Bacterial leaf blight caused by Xanthomonas oryzae pv . oryzae is one of the most important diseases affecting rice production in Asia .
We were interested in surveying rice genotypes that are popularly used in the Indian breeding program for conferring resistance to bacterial blight , using 11 STMS and 6 STS markers .
The basis of selection of these DNA markers was their close linkage to xa5 , xa13 , and Xa21 genes and their positions on the rice genetic map relative to bacterial blight resistance genes .
Eight lines were found to contain the xa5 gene while two lines contained Xa21 gene and none of the lines contained the xa13 gene with the exception of its near-isogenic line .
Using the polymorphic markers obtained in the initial survey , marker-assisted selection was performed in the F3 population of a cross between IR-64 and IET-14444 to detect lines containing multiple resistance genes .
Of the 59 progeny lines analyzed , eight lines contained both the resistance genes , xa5 and Xa4 . | Matching Sentences: [ Sen. 3, subscore: 1.00 ]: Bacterial leaf blight caused by Xanthomonas oryzae pv . oryzae is one of the most important diseases affecting rice production in Asia . We were interested in surveying rice genotypes that are popularly used in the Indian breeding program for conferring resistance to bacterial blight , using 11 STMS and 6 STS markers . The basis of selection of these DNA markers was their close linkage to xa5 , xa13 , and Xa21 genes and their positions on the rice genetic map relative to bacterial blight resistance genes . Eight lines were found to contain the xa5 gene while two lines contained Xa21 gene and none of the lines contained the xa13 gene with the exception of its near-isogenic line . Using the polymorphic markers obtained in the initial survey , marker-assisted selection was performed in the F3 population of a cross between IR-64 and IET-14444 to detect lines containing multiple resistance genes . Of the 59 progeny lines analyzed , eight lines contained both the resistance genes , xa5 and Xa4 . [ Sen. 4, subscore: 1.00 ]: Bacterial leaf blight caused by Xanthomonas oryzae pv . oryzae is one of the most important diseases affecting rice production in Asia . We were interested in surveying rice genotypes that are popularly used in the Indian breeding program for conferring resistance to bacterial blight , using 11 STMS and 6 STS markers . The basis of selection of these DNA markers was their close linkage to xa5 , xa13 , and Xa21 genes and their positions on the rice genetic map relative to bacterial blight resistance genes . Eight lines were found to contain the xa5 gene while two lines contained Xa21 gene and none of the lines contained the xa13 gene with the exception of its near-isogenic line . Using the polymorphic markers obtained in the initial survey , marker-assisted selection was performed in the F3 population of a cross between IR-64 and IET-14444 to detect lines containing multiple resistance genes . Of the 59 progeny lines analyzed , eight lines contained both the resistance genes , xa5 and Xa4 .
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Score: 3.00 | Title: Are the dominant and recessive plant disease resistance genes similar?
A case study of rice R genes and Xanthomonas oryzae pv . oryzae races .
| Author: Li ZK Sanchez A Angeles E Singh S Domingo J Huang N Khush GS .
| Journal: Genetics Citation: V : 159 ( 2 ) P : 757-65 Year: 2001 Type: ARTICLE | Literature: oryza Field: abstract Doc ID: pub11606550 Accession (PMID): 11606550 | Abstract: The resistance of rice to its bacterial blight pathogen Xanthomonas oryzae pv . oryzae ( Xoo ) has both qualitative and quantitative components that were investigated using three near-isogenic line sets for four resistance ( R ) genes ( Xa4 , xa5 , xa13 , and Xa21 ) and 12 Xoo races .
Our results indicate that these two resistance components of rice plants were associated with the properties of the R genes .
The qualitative component of the R genes was reflected by their large effects against corresponding avirulent Xoo races .
The quantitative component of the R genes was their residual effects against corresponding virulent races and their epistatic effects , which together could lead to high-level resistance in a race-specific manner .
Our results revealed important differences between the different types of R genes .
Two R genes , Xa4 and Xa21 , showed complete dominance against the avirulent Xoo races and had large residual effects against virulent ones .
They acted independently and cumulatively , suggesting they are involved in different pathways of the rice defensive system .
The third R gene , xa5 , showed partial dominance or additivity to the avirulent Xoo races and had relatively small but significant residual effects against the virulent races .
In contrast , xa13 was completely recessive , had no residual effects against the virulent races , and showed more pronounced race specificity .
There was a strong interaction leading to increased resistance between xa13 and xa5 and between either of them and Xa4 or Xa21 , suggesting their regulatory roles in the rice defensive pathway ( s ) .
Our results indicated that high-level and durable resistance to Xoo should be more efficiently achieved by pyramiding different types of R genes . | Matching Sentences: [ Sen. 1, subscore: 1.00 ]: The resistance of rice to its bacterial blight pathogen Xanthomonas oryzae pv . oryzae ( Xoo ) has both qualitative and quantitative components that were investigated using three near-isogenic line sets for four resistance ( R ) genes ( Xa4 , xa5 , xa13 , and Xa21 ) and 12 Xoo races . Our results indicate that these two resistance components of rice plants were associated with the properties of the R genes . The qualitative component of the R genes was reflected by their large effects against corresponding avirulent Xoo races . The quantitative component of the R genes was their residual effects against corresponding virulent races and their epistatic effects , which together could lead to high-level resistance in a race-specific manner . Our results revealed important differences between the different types of R genes . [ Sen. 9, subscore: 1.00 ]: Our results revealed important differences between the different types of R genes . Two R genes , Xa4 and Xa21 , showed complete dominance against the avirulent Xoo races and had large residual effects against virulent ones . They acted independently and cumulatively , suggesting they are involved in different pathways of the rice defensive system . The third R gene , xa5 , showed partial dominance or additivity to the avirulent Xoo races and had relatively small but significant residual effects against the virulent races . In contrast , xa13 was completely recessive , had no residual effects against the virulent races , and showed more pronounced race specificity . There was a strong interaction leading to increased resistance between xa13 and xa5 and between either of them and Xa4 or Xa21 , suggesting their regulatory roles in the rice defensive pathway ( s ) . Our results indicated that high-level and durable resistance to Xoo should be more efficiently achieved by pyramiding different types of R genes . [ Sen. 10, subscore: 1.00 ]: Two R genes , Xa4 and Xa21 , showed complete dominance against the avirulent Xoo races and had large residual effects against virulent ones . They acted independently and cumulatively , suggesting they are involved in different pathways of the rice defensive system . The third R gene , xa5 , showed partial dominance or additivity to the avirulent Xoo races and had relatively small but significant residual effects against the virulent races . In contrast , xa13 was completely recessive , had no residual effects against the virulent races , and showed more pronounced race specificity . There was a strong interaction leading to increased resistance between xa13 and xa5 and between either of them and Xa4 or Xa21 , suggesting their regulatory roles in the rice defensive pathway ( s ) . Our results indicated that high-level and durable resistance to Xoo should be more efficiently achieved by pyramiding different types of R genes .
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Score: 1.00 | Title: [ Activities of superoxide dismutase in Xanthomonas oryzae pv . oryzae and its induction ] | Author: Song F Ge X Zheng Z Hu X | Journal: Wei Sheng Wu Xue Bao Citation: V : 40 ( 3 ) P : 301-5 Year: 2000 Type: ARTICLE | Literature: oryza Field: abstract Doc ID: pub12548996 Accession (PMID): 12548996 | Abstract: The activities of superoxide dismutase ( SOD ) in Xanthomonas oryzae pv . oryzae were determined to demonstrate the correlation of SOD activities with the bacterial virulence .
In liquid culture , SOD activities of the tested strains reached the maxima at the end of lag phase and then declined .
The virulent strain PXO99A showed higher SOD activities than the avirulent strain PXO99A ( pBUavr Xa10 . F1 ) .
Analysis on the subcellular location indicated that SOD activities detected from the cytoplasm and periplasm were over 70% and 20%-30% of the total , respectively .
Treatment of the bacterial culture for 1 h with exogenous O2 at concentration of 50-800 mumol/L induced SOD activities of both the strains .
The treatment with 200 mumol/L resulted in the highest SOD activities .
The effect of exogenous O2 on SOD induction was more significant in 12 h-culture than in 24 h-culture , and more notable for the virulent strain PXO99A .
The treatment with exogenous O2 resulted in significantly decreased survival rate off both the strains .
The decreases of survival rate were greater in 24 h-culture than in 12 h-culture , and more significantly for the virulent strain than for the avirulent one . | Matching Sentences: [ Sen. 3, subscore: 1.00 ]: The activities of superoxide dismutase ( SOD ) in Xanthomonas oryzae pv . oryzae were determined to demonstrate the correlation of SOD activities with the bacterial virulence . In liquid culture , SOD activities of the tested strains reached the maxima at the end of lag phase and then declined . The virulent strain PXO99A showed higher SOD activities than the avirulent strain PXO99A ( pBUavr Xa10 . F1 ) . Analysis on the subcellular location indicated that SOD activities detected from the cytoplasm and periplasm were over 70% and 20%-30% of the total , respectively . Treatment of the bacterial culture for 1 h with exogenous O2 at concentration of 50-800 mumol/L induced SOD activities of both the strains . The treatment with 200 mumol/L resulted in the highest SOD activities . The effect of exogenous O2 on SOD induction was more significant in 12 h-culture than in 24 h-culture , and more notable for the virulent strain PXO99A .
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Score: 1.00 | Title: High-resolution mapping of the leaf rust disease resistance gene Lr1 in wheat and characterization of BAC clones from the Lr1 locus .
| Author: Ling HQ Zhu Y Keller B | Journal: Theor . Appl . Genet . Citation: V : 106 ( 5 ) P : 875-82 Year: 2003 Type: ARTICLE | Literature: oryza Field: abstract Doc ID: pub12647062 Accession (PMID): 12647062 | Abstract: Leaf rust is the most common disease in wheat production .
There are more than 45 specific resistance genes described and used in wheat breeding to control epidemics of leaf rust , but none of them has been cloned .
The leaf rust disease resistance gene 1 ( Lr1 ) is a good model gene for isolation by map-based cloning because it is a single , dominant gene which is located in the distal region of chromosome 5DL of wheat .
As the first step towards the isolation of this gene we constructed a high-resolution genetic map in the region of the Lr1 locus by saturation mapping of two large segregating F ( 2 ) populations ( Thatcher Lr1 x Thatcher , Thatcher Lr1 x Frisal ) .
The resistance gene Lr1 was delimited in a 0 . 16-cM region between the RFLP markers ABC718 and PSR567 ( 0 . 12 cM from ABC718 and 0 . 04 cM from PSR567 ) .
A genomic BAC library of Aegilops tauschii ( D genome ) was screened using the RFLP markers ABC718 and PSR567 .
Five positive BAC clones were identified by ABC718 and four clones by PSR567 .
Two NBS-LRR type of resistance gene analogs , which encode proteins highly homologous to the bacterial blight disease resistance protein Xa1 of rice , were identified on BAC clones isolated with PSR567 .
Polymorphic BAC end probes were isolated from both ends of a 105-kb large BAC clone identified by ABC718 .
The end probes were mapped at the same locus as ABC718 , and no recombination event was found within 105 kb around ABC718 in our analysis of more than 4 , 000 gametes .
| Matching Sentences: [ Sen. 8, subscore: 1.00 ]: As the first step towards the isolation of this gene we constructed a high-resolution genetic map in the region of the Lr1 locus by saturation mapping of two large segregating F ( 2 ) populations ( Thatcher Lr1 x Thatcher , Thatcher Lr1 x Frisal ) . The resistance gene Lr1 was delimited in a 0 . 16-cM region between the RFLP markers ABC718 and PSR567 ( 0 . 12 cM from ABC718 and 0 . 04 cM from PSR567 ) . A genomic BAC library of Aegilops tauschii ( D genome ) was screened using the RFLP markers ABC718 and PSR567 . Five positive BAC clones were identified by ABC718 and four clones by PSR567 . Two NBS-LRR type of resistance gene analogs , which encode proteins highly homologous to the bacterial blight disease resistance protein Xa1 of rice , were identified on BAC clones isolated with PSR567 . Polymorphic BAC end probes were isolated from both ends of a 105-kb large BAC clone identified by ABC718 . The end probes were mapped at the same locus as ABC718 , and no recombination event was found within 105 kb around ABC718 in our analysis of more than 4 , 000 gametes .
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Score: 5.00 | Title: Genome-wide analysis of defense-responsive genes in bacterial blight resistance of rice mediated by the recessive R gene xa13 .
| Author: Chu Z Ouyang Y Zhang J Yang H Wang S | Journal: Mol . Genet . Genomics Citation: V : 271 ( 1 ) P : 111-20 Year: 2004 Type: ARTICLE | Literature: oryza Field: abstract Doc ID: pub14730444 Accession (PMID): 14730444 | Abstract: Defense responses triggered by dominant and recessive disease resistance ( R ) genes are presumed to be regulated by different molecular mechanisms .
In order to characterize the genes activated in defense responses against bacterial blight mediated by the recessive R gene xa13 , two pathogen-induced subtraction cDNA libraries were constructed using the resistant rice line IRBB13--which carries xa13--and its susceptible , near-isogenic , parental line IR24 .
Clustering analysis of expressed sequence tags ( ESTs ) identified 702 unique expressed sequences as being involved in the defense responses triggered by xa13 ; 16% of these are new rice ESTs .
These sequences define 702 genes , putatively encoding a wide range of products , including defense-responsive genes commonly involved in different host-pathogen interactions , genes that have not previously been reported to be associated with pathogen-induced defense responses , and genes ( 38% ) with no homology to previously described functional genes .
In addition , R-like genes putatively encoding nucleotide-binding site/leucine rich repeat ( NBS-LRR ) and LRR receptor kinase proteins were observed to be induced in the disease resistance activated by xa13 .
A total of 568 defense-responsive ESTs were mapped to 588 loci on the rice molecular linkage map through bioinformatic analysis .
About 48% of the mapped ESTs co-localized with quantitative trait loci ( QTLs ) for resistance to various rice diseases , including bacterial blight , rice blast , sheath blight and yellow mottle virus .
Furthermore , some defense-responsive sequences were conserved at similar locations on different chromosomes .
These results reveal the complexity of xa13-mediated resistance .
The information obtained in this study provides a large source of candidate genes for understanding the molecular bases of defense responses activated by recessive R genes and of quantitative disease resistance . | Matching Sentences: [ Sen. 2, subscore: 2.00 ]: Defense responses triggered by dominant and recessive disease resistance ( R ) genes are presumed to be regulated by different molecular mechanisms . In order to characterize the genes activated in defense responses against bacterial blight mediated by the recessive R gene xa13 , two pathogen-induced subtraction cDNA libraries were constructed using the resistant rice line IRBB13--which carries xa13--and its susceptible , near-isogenic , parental line IR24 . Clustering analysis of expressed sequence tags ( ESTs ) identified 702 unique expressed sequences as being involved in the defense responses triggered by xa13 ; 16% of these are new rice ESTs . These sequences define 702 genes , putatively encoding a wide range of products , including defense-responsive genes commonly involved in different host-pathogen interactions , genes that have not previously been reported to be associated with pathogen-induced defense responses , and genes ( 38% ) with no homology to previously described functional genes . In addition , R-like genes putatively encoding nucleotide-binding site/leucine rich repeat ( NBS-LRR ) and LRR receptor kinase proteins were observed to be induced in the disease resistance activated by xa13 . A total of 568 defense-responsive ESTs were mapped to 588 loci on the rice molecular linkage map through bioinformatic analysis . [ Sen. 3, subscore: 1.00 ]: Defense responses triggered by dominant and recessive disease resistance ( R ) genes are presumed to be regulated by different molecular mechanisms . In order to characterize the genes activated in defense responses against bacterial blight mediated by the recessive R gene xa13 , two pathogen-induced subtraction cDNA libraries were constructed using the resistant rice line IRBB13--which carries xa13--and its susceptible , near-isogenic , parental line IR24 . Clustering analysis of expressed sequence tags ( ESTs ) identified 702 unique expressed sequences as being involved in the defense responses triggered by xa13 ; 16% of these are new rice ESTs . These sequences define 702 genes , putatively encoding a wide range of products , including defense-responsive genes commonly involved in different host-pathogen interactions , genes that have not previously been reported to be associated with pathogen-induced defense responses , and genes ( 38% ) with no homology to previously described functional genes . In addition , R-like genes putatively encoding nucleotide-binding site/leucine rich repeat ( NBS-LRR ) and LRR receptor kinase proteins were observed to be induced in the disease resistance activated by xa13 . A total of 568 defense-responsive ESTs were mapped to 588 loci on the rice molecular linkage map through bioinformatic analysis . About 48% of the mapped ESTs co-localized with quantitative trait loci ( QTLs ) for resistance to various rice diseases , including bacterial blight , rice blast , sheath blight and yellow mottle virus . [ Sen. 5, subscore: 1.00 ]: Defense responses triggered by dominant and recessive disease resistance ( R ) genes are presumed to be regulated by different molecular mechanisms . In order to characterize the genes activated in defense responses against bacterial blight mediated by the recessive R gene xa13 , two pathogen-induced subtraction cDNA libraries were constructed using the resistant rice line IRBB13--which carries xa13--and its susceptible , near-isogenic , parental line IR24 . Clustering analysis of expressed sequence tags ( ESTs ) identified 702 unique expressed sequences as being involved in the defense responses triggered by xa13 ; 16% of these are new rice ESTs . These sequences define 702 genes , putatively encoding a wide range of products , including defense-responsive genes commonly involved in different host-pathogen interactions , genes that have not previously been reported to be associated with pathogen-induced defense responses , and genes ( 38% ) with no homology to previously described functional genes . In addition , R-like genes putatively encoding nucleotide-binding site/leucine rich repeat ( NBS-LRR ) and LRR receptor kinase proteins were observed to be induced in the disease resistance activated by xa13 . A total of 568 defense-responsive ESTs were mapped to 588 loci on the rice molecular linkage map through bioinformatic analysis . About 48% of the mapped ESTs co-localized with quantitative trait loci ( QTLs ) for resistance to various rice diseases , including bacterial blight , rice blast , sheath blight and yellow mottle virus . Furthermore , some defense-responsive sequences were conserved at similar locations on different chromosomes . These results reveal the complexity of xa13-mediated resistance . [ Sen. 9, subscore: 1.00 ]: In addition , R-like genes putatively encoding nucleotide-binding site/leucine rich repeat ( NBS-LRR ) and LRR receptor kinase proteins were observed to be induced in the disease resistance activated by xa13 . A total of 568 defense-responsive ESTs were mapped to 588 loci on the rice molecular linkage map through bioinformatic analysis . About 48% of the mapped ESTs co-localized with quantitative trait loci ( QTLs ) for resistance to various rice diseases , including bacterial blight , rice blast , sheath blight and yellow mottle virus . Furthermore , some defense-responsive sequences were conserved at similar locations on different chromosomes . These results reveal the complexity of xa13-mediated resistance . The information obtained in this study provides a large source of candidate genes for understanding the molecular bases of defense responses activated by recessive R genes and of quantitative disease resistance .
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Score: 1.00 | Title: RaxH/RaxR : a two-component regulatory system in Xanthomonas oryzae pv . oryzae required for AvrXa21 activity .
| Author: Burdman S Shen Y Lee SW Xue Q Ronald P | Journal: Mol .
Plant Microbe Interact .
Citation: V : 17 ( 6 ) P : 602-12 Year: 2004 Type: ARTICLE | Literature: oryza Field: abstract Doc ID: pub15195943 Accession (PMID): 15195943 | Abstract: Xanthomonas oryzae pv . oryzae is the causal agent of bacterial leaf blight , one of the most serious diseases in rice .
X oryzae pv . oryzae Philippine race 6 ( PR6 ) strains are unable to establish infection in rice lines expressing the resistance gene Xa21 .
Although the pathogen-associated molecule that triggers the Xa21-mediated defense response ( AvrXa21 ) is unknown , six rax ( required for AvrXa21 activity ) genes encoding proteins involved in sulfur metabolism and Type I secretion were recently identified .
Here , we report on the identification of two additional rax genes , raxR and raxH , which encode a response regulator and a histidine protein kinase of two-component regulatory systems , respectively .
Null mutants of PR6 strain PXO99 that are impaired in either raxR , raxH , or both cause lesions significantly longer and grow to significantly higher levels than does the wild-type strain in Xa21-rice leaves .
Both raxR and raxH mutants are complemented to wild-type levels of AvrXa21 activity by introduction of expression vectors carrying raxR and raxH , respectively .
These null mutants do not affect AvrXa7 and AvrXa10 activities , as observed in inoculation experiments with Xa7 and Xa10-rice lines .
Western blot and raxR/gfp promoter-reporter analyses confirmed RaxR expression in X oryzae pv . oryzae .
The results of promoter-reporter studies also suggest that the previously identified raxSTAB operon is a target for RaxH/RaxR regulation .
Characterization of the RaxH/RaxR system provides new opportunities for understanding the specificity of the X oryzae pv . oryzae-Xa21 interaction and may contribute to the identification of AvrXa21 . | Matching Sentences: [ Sen. 7, subscore: 1.00 ]: Although the pathogen-associated molecule that triggers the Xa21-mediated defense response ( AvrXa21 ) is unknown , six rax ( required for AvrXa21 activity ) genes encoding proteins involved in sulfur metabolism and Type I secretion were recently identified . Here , we report on the identification of two additional rax genes , raxR and raxH , which encode a response regulator and a histidine protein kinase of two-component regulatory systems , respectively . Null mutants of PR6 strain PXO99 that are impaired in either raxR , raxH , or both cause lesions significantly longer and grow to significantly higher levels than does the wild-type strain in Xa21-rice leaves . Both raxR and raxH mutants are complemented to wild-type levels of AvrXa21 activity by introduction of expression vectors carrying raxR and raxH , respectively . These null mutants do not affect AvrXa7 and AvrXa10 activities , as observed in inoculation experiments with Xa7 and Xa10-rice lines . Western blot and raxR/gfp promoter-reporter analyses confirmed RaxR expression in X oryzae pv . oryzae . The results of promoter-reporter studies also suggest that the previously identified raxSTAB operon is a target for RaxH/RaxR regulation . Characterization of the RaxH/RaxR system provides new opportunities for understanding the specificity of the X oryzae pv . oryzae-Xa21 interaction and may contribute to the identification of AvrXa21 .
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Score: 1.00 | Title: Characterization of the hrpF pathogenicity peninsula of Xanthomonas oryzae pv . oryzae .
| Author: Sugio A Yang B White FF .
| Journal: Mol .
Plant Microbe Interact .
Citation: V : 18 ( 6 ) P : 546-54 Year: 2005 Type: ARTICLE | Literature: oryza Field: abstract Doc ID: pub15986924 Accession (PMID): 15986924 | Abstract: The hrp gene cluster of Xanthomonas spp . contains genes for the assembly and function of a type III secretion system ( TTSS ) .
The hrpF genes reside in a region between hpaB and the right end of the hrp cluster .
The region of the hrpF gene of Xanthomonas oryzae pv . oryzae is bounded by two IS elements and also contains a homolog of hpaF of X campestris pv . vesicatoria and two newly identified genes , hpa3 and hpa4 .
A comparison of the hrp gene clusters of different species of Xanthomonas revealed that the hrpF region is a constant yet more variable peninsula of the hrp pathogenicity island .
Mutations in hpaF , hpa3 , and hpa4 had no effect on virulence , whereas hrpF mutants were severely reduced in virulence on susceptible rice cultivars .
The hrpF genes from X campestris pv . vesicatoria , X campestris pv . campestris , and X axonopodis pv . citri each were capable of restoring virulence to the hrpF mutant of X oryzae pv . oryzae .
Correspondingly , none of the Xanthomonas pathovars with hrpF from X oryzae pv . oryzae elicited a hypersensitive reaction in their respective hosts .
Therefore , no evidence was found for hrpF as a host-specialization factor .
In contrast to the loss of Bs3-dependent reactions by hrpF mutants of X campestris pv . vesicatoria , hrpF mutants of X oryzae pv . oryzae with either avrXa10 or avrXa7 elicited hypersensitive reactions in rice cultivars with the corresponding R genes .
A double hrpFxoo-hpa1 mutant also elicited an Xa10-dependent resistance reaction .
Thus , loss of hrpF , hpal , or both may reduce delivery or effectiveness of type III effectors .
However , the mutations did not completely prevent the delivery of effectors from X oryzae pv . oryzae into the host cells . | Matching Sentences: [ Sen. 10, subscore: 1.00 ]: The hrpF genes from X campestris pv . vesicatoria , X campestris pv . campestris , and X axonopodis pv . citri each were capable of restoring virulence to the hrpF mutant of X oryzae pv . oryzae . Correspondingly , none of the Xanthomonas pathovars with hrpF from X oryzae pv . oryzae elicited a hypersensitive reaction in their respective hosts . Therefore , no evidence was found for hrpF as a host-specialization factor . In contrast to the loss of Bs3-dependent reactions by hrpF mutants of X campestris pv . vesicatoria , hrpF mutants of X oryzae pv . oryzae with either avrXa10 or avrXa7 elicited hypersensitive reactions in rice cultivars with the corresponding R genes . A double hrpFxoo-hpa1 mutant also elicited an Xa10-dependent resistance reaction . Thus , loss of hrpF , hpal , or both may reduce delivery or effectiveness of type III effectors . However , the mutations did not completely prevent the delivery of effectors from X oryzae pv . oryzae into the host cells .
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Score: 4.00 | Title: Targeting xa13 , a recessive gene for bacterial blight resistance in rice .
| Author: Chu Z Fu B Yang H Xu C Li Z Sanchez A Park YJ Bennetzen JL Zhang Q Wang S | Journal: Theor . Appl . Genet . Citation: V : 112 ( 3 ) P : 455-61 Year: 2006 Type: ARTICLE | Literature: oryza Field: abstract Doc ID: pub16328230 Accession (PMID): 16328230 | Abstract: Bacterial blight , caused by Xanthomonas oryzae pv . oryzae ( Xoo ) , is one of the most serious diseases of rice worldwide .
Thirty bacterial blight resistance ( R ) genes ( 21 dominant genes and 9 recessive genes ) in rice have been identified .
They are the main sources for the genetic improvement of rice for resistance to Xoo .
However , little is known about the recessive R genes .
To clone and characterize the recessive R genes , we fine-mapped xa13 , a fully recessive gene for Xoo resistance , to a DNA fragment of 14 . 8 kb using the map-based cloning strategy and a series of sequence-based molecular markers .
Sequence analysis of this fragment indicated that this region contains only two apparently intact candidate genes ( an extensin-like gene and a homologue of nodulin MtN3 ) and the 5 end of a predicted hypothetical gene .
These results will greatly facilitate the isolation and characterization of xa13 .
Four PCR-based markers , E6a , SR6 , ST9 and SR11 that were tightly linked to the xa13 locus , were also developed .
These markers will be useful tools for the marker-assisted selection of xa13 in breeding programs . | Matching Sentences: [ Sen. 5, subscore: 1.00 ]: Bacterial blight , caused by Xanthomonas oryzae pv . oryzae ( Xoo ) , is one of the most serious diseases of rice worldwide . Thirty bacterial blight resistance ( R ) genes ( 21 dominant genes and 9 recessive genes ) in rice have been identified . They are the main sources for the genetic improvement of rice for resistance to Xoo . However , little is known about the recessive R genes . To clone and characterize the recessive R genes , we fine-mapped xa13 , a fully recessive gene for Xoo resistance , to a DNA fragment of 14 . 8 kb using the map-based cloning strategy and a series of sequence-based molecular markers . Sequence analysis of this fragment indicated that this region contains only two apparently intact candidate genes ( an extensin-like gene and a homologue of nodulin MtN3 ) and the 5 end of a predicted hypothetical gene . These results will greatly facilitate the isolation and characterization of xa13 . Four PCR-based markers , E6a , SR6 , ST9 and SR11 that were tightly linked to the xa13 locus , were also developed . These markers will be useful tools for the marker-assisted selection of xa13 in breeding programs . [ Sen. 7, subscore: 1.00 ]: They are the main sources for the genetic improvement of rice for resistance to Xoo . However , little is known about the recessive R genes . To clone and characterize the recessive R genes , we fine-mapped xa13 , a fully recessive gene for Xoo resistance , to a DNA fragment of 14 . 8 kb using the map-based cloning strategy and a series of sequence-based molecular markers . Sequence analysis of this fragment indicated that this region contains only two apparently intact candidate genes ( an extensin-like gene and a homologue of nodulin MtN3 ) and the 5 end of a predicted hypothetical gene . These results will greatly facilitate the isolation and characterization of xa13 . Four PCR-based markers , E6a , SR6 , ST9 and SR11 that were tightly linked to the xa13 locus , were also developed . These markers will be useful tools for the marker-assisted selection of xa13 in breeding programs . [ Sen. 8, subscore: 1.00 ]: However , little is known about the recessive R genes . To clone and characterize the recessive R genes , we fine-mapped xa13 , a fully recessive gene for Xoo resistance , to a DNA fragment of 14 . 8 kb using the map-based cloning strategy and a series of sequence-based molecular markers . Sequence analysis of this fragment indicated that this region contains only two apparently intact candidate genes ( an extensin-like gene and a homologue of nodulin MtN3 ) and the 5 end of a predicted hypothetical gene . These results will greatly facilitate the isolation and characterization of xa13 . Four PCR-based markers , E6a , SR6 , ST9 and SR11 that were tightly linked to the xa13 locus , were also developed . These markers will be useful tools for the marker-assisted selection of xa13 in breeding programs . [ Sen. 9, subscore: 1.00 ]: To clone and characterize the recessive R genes , we fine-mapped xa13 , a fully recessive gene for Xoo resistance , to a DNA fragment of 14 . 8 kb using the map-based cloning strategy and a series of sequence-based molecular markers . Sequence analysis of this fragment indicated that this region contains only two apparently intact candidate genes ( an extensin-like gene and a homologue of nodulin MtN3 ) and the 5 end of a predicted hypothetical gene . These results will greatly facilitate the isolation and characterization of xa13 . Four PCR-based markers , E6a , SR6 , ST9 and SR11 that were tightly linked to the xa13 locus , were also developed . These markers will be useful tools for the marker-assisted selection of xa13 in breeding programs .
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Score: 5.00 | Title: Promoter mutations of an essential gene for pollen development result in disease resistance in rice .
| Author: Chu Z Yuan M Yao J Ge X Yuan B Xu C Li X Fu B Li Z Bennetzen JL Zhang Q Wang S | Journal: Genes Dev .
Citation: V : 20 ( 10 ) P : 1250-5 Year: 2006 Type: ARTICLE | Literature: oryza Field: abstract Doc ID: pub16648463 Accession (PMID): 16648463 | Abstract: Disease resistance and sexual reproductive development are generally considered as separate biological processes , regulated by different sets of genes .
Here we show that xa13 , a recessive allele conferring disease resistance against bacterial blight , one of the most devastating rice diseases worldwide , plays a key role in both disease resistance and pollen development .
The dominant allele , Xa13 , is required for both bacterial growth and pollen development .
Promoter mutations in Xa13 cause down-regulation of expression during host-pathogen interaction , resulting in the fully recessive xa13 that confers race-specific resistance .
The recessive xa13 allele represents a new type of plant disease resistance . | Matching Sentences: [ Sen. 4, subscore: 2.00 ]: Disease resistance and sexual reproductive development are generally considered as separate biological processes , regulated by different sets of genes . Here we show that xa13 , a recessive allele conferring disease resistance against bacterial blight , one of the most devastating rice diseases worldwide , plays a key role in both disease resistance and pollen development . The dominant allele , Xa13 , is required for both bacterial growth and pollen development . Promoter mutations in Xa13 cause down-regulation of expression during host-pathogen interaction , resulting in the fully recessive xa13 that confers race-specific resistance . The recessive xa13 allele represents a new type of plant disease resistance . [ Sen. 2, subscore: 1.00 ]: Disease resistance and sexual reproductive development are generally considered as separate biological processes , regulated by different sets of genes . Here we show that xa13 , a recessive allele conferring disease resistance against bacterial blight , one of the most devastating rice diseases worldwide , plays a key role in both disease resistance and pollen development . The dominant allele , Xa13 , is required for both bacterial growth and pollen development . Promoter mutations in Xa13 cause down-regulation of expression during host-pathogen interaction , resulting in the fully recessive xa13 that confers race-specific resistance . The recessive xa13 allele represents a new type of plant disease resistance . [ Sen. 3, subscore: 1.00 ]: Disease resistance and sexual reproductive development are generally considered as separate biological processes , regulated by different sets of genes . Here we show that xa13 , a recessive allele conferring disease resistance against bacterial blight , one of the most devastating rice diseases worldwide , plays a key role in both disease resistance and pollen development . The dominant allele , Xa13 , is required for both bacterial growth and pollen development . Promoter mutations in Xa13 cause down-regulation of expression during host-pathogen interaction , resulting in the fully recessive xa13 that confers race-specific resistance . The recessive xa13 allele represents a new type of plant disease resistance . [ Sen. 5, subscore: 1.00 ]: Disease resistance and sexual reproductive development are generally considered as separate biological processes , regulated by different sets of genes . Here we show that xa13 , a recessive allele conferring disease resistance against bacterial blight , one of the most devastating rice diseases worldwide , plays a key role in both disease resistance and pollen development . The dominant allele , Xa13 , is required for both bacterial growth and pollen development . Promoter mutations in Xa13 cause down-regulation of expression during host-pathogen interaction , resulting in the fully recessive xa13 that confers race-specific resistance . The recessive xa13 allele represents a new type of plant disease resistance .
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Score: 3.00 | Title: Os8N3 is a host disease-susceptibility gene for bacterial blight of rice .
| Author: Yang B Sugio A White FF .
| Journal: Proc . Natl . Acad . Sci . USA Citation: V : 103 ( 27 ) P : 10503-8 Year: 2006 Type: ARTICLE | Literature: oryza Field: abstract Doc ID: pub16798873 Accession (PMID): 16798873 | Abstract: Many bacterial diseases of plants depend on the interaction of type III effector genes of the pathogen and disease-susceptibility genes of the host The host susceptibility genes are largely unknown .
Here , we show that expression of the rice gene Os8N3 , a member of the MtN3 gene family from plants and animals , is elevated upon infection by Xanthomonas oryzae pv . oryzae strain PXO99 ( A ) and depends on the type III effector gene pthXo1 .
Os8N3 resides near xa13 , and PXO99 ( A ) failed to induce Os8N3 in rice lines with xa13 .
Silencing of Os8N3 by inhibitory RNA produced plants that were resistant to infection by strain PXO99 ( A ) yet remained susceptible to other strains of the pathogen .
The effector gene avrXa7 from strain PXO86 enabled PXO99 ( A ) compatibility on either xa13 or Os8N3-silenced plants .
The findings indicate that Os8N3 is a host susceptibility gene for bacterial blight targeted by the type III effector PthXo1 .
The results support the hypothesis that X oryzae pv . oryzae commandeers the regulation of otherwise developmentally regulated host genes to induce a state of disease susceptibility .
Furthermore , the results support a model in which the pathogen induces disease susceptibility in a gene-for-gene manner . | Matching Sentences: [ Sen. 3, subscore: 2.00 ]: Many bacterial diseases of plants depend on the interaction of type III effector genes of the pathogen and disease-susceptibility genes of the host The host susceptibility genes are largely unknown . Here , we show that expression of the rice gene Os8N3 , a member of the MtN3 gene family from plants and animals , is elevated upon infection by Xanthomonas oryzae pv . oryzae strain PXO99 ( A ) and depends on the type III effector gene pthXo1 . Os8N3 resides near xa13 , and PXO99 ( A ) failed to induce Os8N3 in rice lines with xa13 . Silencing of Os8N3 by inhibitory RNA produced plants that were resistant to infection by strain PXO99 ( A ) yet remained susceptible to other strains of the pathogen . The effector gene avrXa7 from strain PXO86 enabled PXO99 ( A ) compatibility on either xa13 or Os8N3-silenced plants . The findings indicate that Os8N3 is a host susceptibility gene for bacterial blight targeted by the type III effector PthXo1 . The results support the hypothesis that X oryzae pv . oryzae commandeers the regulation of otherwise developmentally regulated host genes to induce a state of disease susceptibility . [ Sen. 5, subscore: 1.00 ]: Many bacterial diseases of plants depend on the interaction of type III effector genes of the pathogen and disease-susceptibility genes of the host The host susceptibility genes are largely unknown . Here , we show that expression of the rice gene Os8N3 , a member of the MtN3 gene family from plants and animals , is elevated upon infection by Xanthomonas oryzae pv . oryzae strain PXO99 ( A ) and depends on the type III effector gene pthXo1 . Os8N3 resides near xa13 , and PXO99 ( A ) failed to induce Os8N3 in rice lines with xa13 . Silencing of Os8N3 by inhibitory RNA produced plants that were resistant to infection by strain PXO99 ( A ) yet remained susceptible to other strains of the pathogen . The effector gene avrXa7 from strain PXO86 enabled PXO99 ( A ) compatibility on either xa13 or Os8N3-silenced plants . The findings indicate that Os8N3 is a host susceptibility gene for bacterial blight targeted by the type III effector PthXo1 . The results support the hypothesis that X oryzae pv . oryzae commandeers the regulation of otherwise developmentally regulated host genes to induce a state of disease susceptibility . Furthermore , the results support a model in which the pathogen induces disease susceptibility in a gene-for-gene manner .
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Score: 2.00 | Title: Recessive bacterial leaf blight resistance in rice : complexity , challenges and strategy .
| Author: Kottapalli KR Kottapalli P Agrawal GK Kikuchi S Rakwal R | Journal: Biochem . Biophys . Res . Commun . Citation: V : 355 ( 2 ) P : 295-301 Year: 2007 Type: ARTICLE | Literature: oryza Field: abstract Doc ID: pub17307154 Accession (PMID): 17307154 | Abstract: Physical mapping and map-based cloning strategies are routinely used for identification of candidate genes for major qualitative traits in rice .
Such strategies have enabled mapping and characterization of dominant bacterial leaf blight ( blb ) resistance genes , but little progress has been made in case of the recessive resistance genes .
Two recent studies on map-based cloning of xa5 and xa13 recessive blb resistance genes identified the general transcription factor IIA gamma subunit ( TFIIAgamma ) and the nodulin MtN21 as candidates , respectively .
Subsequently , two other reports have raised discussion on whether the identified candidates are indeed recessive resistance genes , and are sufficient to confer blb resistance in rice .
Based on published evidence , and our extensive in silico analyses of the genomic environment around xa5 and xa13 regions , we propose that the recessive gene mediated resistance mechanism is more complex and might not be governed by a single gene .
| Matching Sentences: [ Sen. 3, subscore: 1.00 ]: Physical mapping and map-based cloning strategies are routinely used for identification of candidate genes for major qualitative traits in rice . Such strategies have enabled mapping and characterization of dominant bacterial leaf blight ( blb ) resistance genes , but little progress has been made in case of the recessive resistance genes . Two recent studies on map-based cloning of xa5 and xa13 recessive blb resistance genes identified the general transcription factor IIA gamma subunit ( TFIIAgamma ) and the nodulin MtN21 as candidates , respectively . Subsequently , two other reports have raised discussion on whether the identified candidates are indeed recessive resistance genes , and are sufficient to confer blb resistance in rice . Based on published evidence , and our extensive in silico analyses of the genomic environment around xa5 and xa13 regions , we propose that the recessive gene mediated resistance mechanism is more complex and might not be governed by a single gene . [ Sen. 5, subscore: 1.00 ]: Physical mapping and map-based cloning strategies are routinely used for identification of candidate genes for major qualitative traits in rice . Such strategies have enabled mapping and characterization of dominant bacterial leaf blight ( blb ) resistance genes , but little progress has been made in case of the recessive resistance genes . Two recent studies on map-based cloning of xa5 and xa13 recessive blb resistance genes identified the general transcription factor IIA gamma subunit ( TFIIAgamma ) and the nodulin MtN21 as candidates , respectively . Subsequently , two other reports have raised discussion on whether the identified candidates are indeed recessive resistance genes , and are sufficient to confer blb resistance in rice . Based on published evidence , and our extensive in silico analyses of the genomic environment around xa5 and xa13 regions , we propose that the recessive gene mediated resistance mechanism is more complex and might not be governed by a single gene .
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Score: 1.00 | Title: Recessive resistance genes and the Oryza sativa-Xanthomonas oryzae pv . oryzae pathosystem .
| Author: Iyer-Pascuzzi AS McCouch SR | Journal: Mol Plant Microbe Interact Citation: V : 20 P : 731-9 Year: 2007 Type: MEDLINE | Literature: oryza Field: abstract Doc ID: pub17601161 Accession (PMID): 17601161 | Abstract: Though recessive resistance is well-studied in viral systems , little is understood regarding the phenomenon in plant-bacterial interactions .
The Oryza sativa-Xanthomonas oryzae pv . orzyae pathosystem provides an excellent opportunity to examine recessive resistance in plant-bacterial interactions , in which nine of 30 documented resistance ( R ) genes are recessively inherited .
Infestations of X oryzae pv . oryzae , the causal agent of bacterial blight , result in significant crop loss and damage throughout South and Southeast Asia .
Two recently cloned novel recessive R genes , xa5 and xa13 , have yielded insights to this system .
Like their viral counterparts , these bacterial recessive R gene products do not conform to the five commonly described classes of R proteins .
New findings suggest that such genes may more aptly be viewed as mutations in dominant susceptibility alleles and may also function in a gene-for-gene manner .
In this review , we discuss recent accomplishments in the understanding of recessively inherited R genes in the rice-bacterial blight pathosystem and suggest a new model for the function of recessive resistance in plant-bacterial interactions .
| Matching Sentences: [ Sen. 4, subscore: 1.00 ]: Though recessive resistance is well-studied in viral systems , little is understood regarding the phenomenon in plant-bacterial interactions . The Oryza sativa-Xanthomonas oryzae pv . orzyae pathosystem provides an excellent opportunity to examine recessive resistance in plant-bacterial interactions , in which nine of 30 documented resistance ( R ) genes are recessively inherited . Infestations of X oryzae pv . oryzae , the causal agent of bacterial blight , result in significant crop loss and damage throughout South and Southeast Asia . Two recently cloned novel recessive R genes , xa5 and xa13 , have yielded insights to this system . Like their viral counterparts , these bacterial recessive R gene products do not conform to the five commonly described classes of R proteins . New findings suggest that such genes may more aptly be viewed as mutations in dominant susceptibility alleles and may also function in a gene-for-gene manner . In this review , we discuss recent accomplishments in the understanding of recessively inherited R genes in the rice-bacterial blight pathosystem and suggest a new model for the function of recessive resistance in plant-bacterial interactions .
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Score: 8.00 | Title: High-resolution genetic mapping of bacterial blight resistance gene Xa10 .
| Author: Gu K Sangha JS Li Y Yin Z | Journal: Theor Appl Genet Citation: V : 116 P : 155-63 Year: 2008 Type: MEDLINE | Literature: oryza Field: abstract Doc ID: pub17924090 Accession (PMID): 17924090 | Abstract: Bacterial blight of rice , caused by Xanthomonas oryzae pv . oryzae ( Xoo ) , is the most devastating disease of rice ( Oryza sativa L ) .
Rice lines that carry resistance ( R ) gene Xa10 confer race-specific resistance to Xoo strains harboring avirulence ( Avr ) gene avrXa10 .
Here we report on genetic study , disease evaluation and fine genetic mapping of the Xa10 gene .
The inheritance of Xa10-mediated resistance to PXO99A ( pHM1avrXa10 ) did not follow typical Mendelian inheritance for single dominant gene in F2 population derived from IR24 x IRBB10 .
A locus might be present in IRBB10 that caused distorted segregation in F2 population .
To eliminate this locus , an F3 population ( F3-65 ) was identified , which showed normal Mendelian segregation ratio of 3 : 1 for resistance and susceptibility .
A new near-isogenic line ( F3-65-1743 ) of Xa10 in IR24 genetic background was developed and designated as IRBB10A .
IRBB10A retained similar resistance specificity as that of IRBB10 and provided complete resistance to PXO99A ( pHM1avrXa10 ) from seedling to adult stages .
Linkage analysis using existing RFLP markers and F2 mapping population mapped the Xa10 locus to the proximal side of E1981S with genetic distance at 0 . 93 cM .
With five new RFLP markers developed from the genomic sequence of Nipponbare , Xa10 was finely mapped at genetic distance of 0 . 28 cM between proximal marker M491 and distal marker M419 and co-segregated with markers S723 and M604 .
The physical distance between M491 and M419 on Nipponbare genome is 74 kb .
Seven genes have been annotated from this 74-kb region and six of them are possible Xa10 candidates .
The results of this study will be useful in Xa10 cloning and marker-assisted breeding .
| Matching Sentences: [ Sen. 2, subscore: 1.00 ]: Bacterial blight of rice , caused by Xanthomonas oryzae pv . oryzae ( Xoo ) , is the most devastating disease of rice ( Oryza sativa L ) . Rice lines that carry resistance ( R ) gene Xa10 confer race-specific resistance to Xoo strains harboring avirulence ( Avr ) gene avrXa10 . Here we report on genetic study , disease evaluation and fine genetic mapping of the Xa10 gene . The inheritance of Xa10-mediated resistance to PXO99A ( pHM1avrXa10 ) did not follow typical Mendelian inheritance for single dominant gene in F2 population derived from IR24 x IRBB10 . A locus might be present in IRBB10 that caused distorted segregation in F2 population . To eliminate this locus , an F3 population ( F3-65 ) was identified , which showed normal Mendelian segregation ratio of 3 : 1 for resistance and susceptibility . [ Sen. 3, subscore: 1.00 ]: Bacterial blight of rice , caused by Xanthomonas oryzae pv . oryzae ( Xoo ) , is the most devastating disease of rice ( Oryza sativa L ) . Rice lines that carry resistance ( R ) gene Xa10 confer race-specific resistance to Xoo strains harboring avirulence ( Avr ) gene avrXa10 . Here we report on genetic study , disease evaluation and fine genetic mapping of the Xa10 gene . The inheritance of Xa10-mediated resistance to PXO99A ( pHM1avrXa10 ) did not follow typical Mendelian inheritance for single dominant gene in F2 population derived from IR24 x IRBB10 . A locus might be present in IRBB10 that caused distorted segregation in F2 population . To eliminate this locus , an F3 population ( F3-65 ) was identified , which showed normal Mendelian segregation ratio of 3 : 1 for resistance and susceptibility . A new near-isogenic line ( F3-65-1743 ) of Xa10 in IR24 genetic background was developed and designated as IRBB10A . [ Sen. 4, subscore: 1.00 ]: Bacterial blight of rice , caused by Xanthomonas oryzae pv . oryzae ( Xoo ) , is the most devastating disease of rice ( Oryza sativa L ) . Rice lines that carry resistance ( R ) gene Xa10 confer race-specific resistance to Xoo strains harboring avirulence ( Avr ) gene avrXa10 . Here we report on genetic study , disease evaluation and fine genetic mapping of the Xa10 gene . The inheritance of Xa10-mediated resistance to PXO99A ( pHM1avrXa10 ) did not follow typical Mendelian inheritance for single dominant gene in F2 population derived from IR24 x IRBB10 . A locus might be present in IRBB10 that caused distorted segregation in F2 population . To eliminate this locus , an F3 population ( F3-65 ) was identified , which showed normal Mendelian segregation ratio of 3 : 1 for resistance and susceptibility . A new near-isogenic line ( F3-65-1743 ) of Xa10 in IR24 genetic background was developed and designated as IRBB10A . IRBB10A retained similar resistance specificity as that of IRBB10 and provided complete resistance to PXO99A ( pHM1avrXa10 ) from seedling to adult stages . [ Sen. 7, subscore: 1.00 ]: Here we report on genetic study , disease evaluation and fine genetic mapping of the Xa10 gene . The inheritance of Xa10-mediated resistance to PXO99A ( pHM1avrXa10 ) did not follow typical Mendelian inheritance for single dominant gene in F2 population derived from IR24 x IRBB10 . A locus might be present in IRBB10 that caused distorted segregation in F2 population . To eliminate this locus , an F3 population ( F3-65 ) was identified , which showed normal Mendelian segregation ratio of 3 : 1 for resistance and susceptibility . A new near-isogenic line ( F3-65-1743 ) of Xa10 in IR24 genetic background was developed and designated as IRBB10A . IRBB10A retained similar resistance specificity as that of IRBB10 and provided complete resistance to PXO99A ( pHM1avrXa10 ) from seedling to adult stages . Linkage analysis using existing RFLP markers and F2 mapping population mapped the Xa10 locus to the proximal side of E1981S with genetic distance at 0 . 93 cM . With five new RFLP markers developed from the genomic sequence of Nipponbare , Xa10 was finely mapped at genetic distance of 0 . 28 cM between proximal marker M491 and distal marker M419 and co-segregated with markers S723 and M604 . The physical distance between M491 and M419 on Nipponbare genome is 74 kb . [ Sen. 9, subscore: 1.00 ]: A locus might be present in IRBB10 that caused distorted segregation in F2 population . To eliminate this locus , an F3 population ( F3-65 ) was identified , which showed normal Mendelian segregation ratio of 3 : 1 for resistance and susceptibility . A new near-isogenic line ( F3-65-1743 ) of Xa10 in IR24 genetic background was developed and designated as IRBB10A . IRBB10A retained similar resistance specificity as that of IRBB10 and provided complete resistance to PXO99A ( pHM1avrXa10 ) from seedling to adult stages . Linkage analysis using existing RFLP markers and F2 mapping population mapped the Xa10 locus to the proximal side of E1981S with genetic distance at 0 . 93 cM . With five new RFLP markers developed from the genomic sequence of Nipponbare , Xa10 was finely mapped at genetic distance of 0 . 28 cM between proximal marker M491 and distal marker M419 and co-segregated with markers S723 and M604 . The physical distance between M491 and M419 on Nipponbare genome is 74 kb . Seven genes have been annotated from this 74-kb region and six of them are possible Xa10 candidates . The results of this study will be useful in Xa10 cloning and marker-assisted breeding . [ Sen. 10, subscore: 1.00 ]: To eliminate this locus , an F3 population ( F3-65 ) was identified , which showed normal Mendelian segregation ratio of 3 : 1 for resistance and susceptibility . A new near-isogenic line ( F3-65-1743 ) of Xa10 in IR24 genetic background was developed and designated as IRBB10A . IRBB10A retained similar resistance specificity as that of IRBB10 and provided complete resistance to PXO99A ( pHM1avrXa10 ) from seedling to adult stages . Linkage analysis using existing RFLP markers and F2 mapping population mapped the Xa10 locus to the proximal side of E1981S with genetic distance at 0 . 93 cM . With five new RFLP markers developed from the genomic sequence of Nipponbare , Xa10 was finely mapped at genetic distance of 0 . 28 cM between proximal marker M491 and distal marker M419 and co-segregated with markers S723 and M604 . The physical distance between M491 and M419 on Nipponbare genome is 74 kb . Seven genes have been annotated from this 74-kb region and six of them are possible Xa10 candidates . The results of this study will be useful in Xa10 cloning and marker-assisted breeding . [ Sen. 12, subscore: 1.00 ]: IRBB10A retained similar resistance specificity as that of IRBB10 and provided complete resistance to PXO99A ( pHM1avrXa10 ) from seedling to adult stages . Linkage analysis using existing RFLP markers and F2 mapping population mapped the Xa10 locus to the proximal side of E1981S with genetic distance at 0 . 93 cM . With five new RFLP markers developed from the genomic sequence of Nipponbare , Xa10 was finely mapped at genetic distance of 0 . 28 cM between proximal marker M491 and distal marker M419 and co-segregated with markers S723 and M604 . The physical distance between M491 and M419 on Nipponbare genome is 74 kb . Seven genes have been annotated from this 74-kb region and six of them are possible Xa10 candidates . The results of this study will be useful in Xa10 cloning and marker-assisted breeding . [ Sen. 13, subscore: 1.00 ]: Linkage analysis using existing RFLP markers and F2 mapping population mapped the Xa10 locus to the proximal side of E1981S with genetic distance at 0 . 93 cM . With five new RFLP markers developed from the genomic sequence of Nipponbare , Xa10 was finely mapped at genetic distance of 0 . 28 cM between proximal marker M491 and distal marker M419 and co-segregated with markers S723 and M604 . The physical distance between M491 and M419 on Nipponbare genome is 74 kb . Seven genes have been annotated from this 74-kb region and six of them are possible Xa10 candidates . The results of this study will be useful in Xa10 cloning and marker-assisted breeding .
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Score: 1.00 | Title: Constitutive expression of a rice GTPase-activating protein induces defense responses .
| Author: Cheung MY Zeng NY Tong SW Li WY Xue Y Zhao KJ Wang C Zhang Q Fu Y Sun Z Sun SS Lam HM | Journal: New Phytol Citation: V : P : Year: 2080 Type: Publisher | Literature: oryza Field: abstract Doc ID: pub18466220 Accession (PMID): 18466220 | Abstract: * G-proteins ( guanine nucleotide-binding proteins that usually exhibit GTPase activities ) and related signal transduction processes play important roles in mediating plant defense responses ; here , a rice ( Oryza sativa ) cDNA clone , OsGAP1 , encoding a GTPase-activating protein ( GAP ) that also contains a protein kinase C conserved region 2 ( C2 ) domain is reported .
* An interacting G-protein partner for the OsGAP1 protein was identified by yeast two-hybrid library screening and confirmed by co-immunoprecipitation ; the GTPase-activation activity of OsGAP1 on this interacting G-protein was demonstrated using in vitro assays .
* OsGAP1 was induced by wounding in rice and the presence of the R locus Xa14 enhances such induction .
* Gain-of-function tests in transgenic rice and Arabidopsis thaliana showed that constitutive expression of OsGAP1 led to increased resistance to bacterial pathogens in both monocots and dicots .
| Matching Sentences: [ Sen. 3, subscore: 1.00 ]: * G-proteins ( guanine nucleotide-binding proteins that usually exhibit GTPase activities ) and related signal transduction processes play important roles in mediating plant defense responses ; here , a rice ( Oryza sativa ) cDNA clone , OsGAP1 , encoding a GTPase-activating protein ( GAP ) that also contains a protein kinase C conserved region 2 ( C2 ) domain is reported . * An interacting G-protein partner for the OsGAP1 protein was identified by yeast two-hybrid library screening and confirmed by co-immunoprecipitation ; the GTPase-activation activity of OsGAP1 on this interacting G-protein was demonstrated using in vitro assays . * OsGAP1 was induced by wounding in rice and the presence of the R locus Xa14 enhances such induction . * Gain-of-function tests in transgenic rice and Arabidopsis thaliana showed that constitutive expression of OsGAP1 led to increased resistance to bacterial pathogens in both monocots and dicots .
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Score: 1.00 | Title: Constitutive expression of a rice GTPase-activating protein induces defense responses .
| Author: Cheung MY Zeng NY Tong SW Li WY Xue Y Zhao KJ Wang C Zhang Q Fu Y Sun Z Sun SS Lam HM | Journal: New Phytol Citation: V : 179 P : 530-45 Year: 2008 Type: MEDLINE | Literature: oryza Field: abstract Doc ID: pub19086295 Accession (PMID): 19086295 | Abstract: G-proteins ( guanine nucleotide-binding proteins that usually exhibit GTPase activities ) and related signal transduction processes play important roles in mediating plant defense responses ; here , a rice ( Oryza sativa ) cDNA clone , OsGAP1 , encoding a GTPase-activating protein ( GAP ) that also contains a protein kinase C conserved region 2 ( C2 ) domain is reported .
An interacting G-protein partner for the OsGAP1 protein was identified by yeast two-hybrid library screening and confirmed by co-immunoprecipitation ; the GTPase-activation activity of OsGAP1 on this interacting G-protein was demonstrated using in vitro assays .
OsGAP1 was induced by wounding in rice and the presence of the R locus Xa14 enhances such induction .
Gain-of-function tests in transgenic rice and Arabidopsis thaliana showed that constitutive expression of OsGAP1 led to increased resistance to bacterial pathogens in both monocots and dicots .
| Matching Sentences: [ Sen. 3, subscore: 1.00 ]: G-proteins ( guanine nucleotide-binding proteins that usually exhibit GTPase activities ) and related signal transduction processes play important roles in mediating plant defense responses ; here , a rice ( Oryza sativa ) cDNA clone , OsGAP1 , encoding a GTPase-activating protein ( GAP ) that also contains a protein kinase C conserved region 2 ( C2 ) domain is reported . An interacting G-protein partner for the OsGAP1 protein was identified by yeast two-hybrid library screening and confirmed by co-immunoprecipitation ; the GTPase-activation activity of OsGAP1 on this interacting G-protein was demonstrated using in vitro assays . OsGAP1 was induced by wounding in rice and the presence of the R locus Xa14 enhances such induction . Gain-of-function tests in transgenic rice and Arabidopsis thaliana showed that constitutive expression of OsGAP1 led to increased resistance to bacterial pathogens in both monocots and dicots .
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Score: 2.00 | Title: Introduction of bacterial blight resistance into Triguna , a high yielding , mid-early duration rice variety .
| Author: Sundaram RM Vishnupriya MR Laha GS Rani NS Rao PS Balachandran SM Reddy GA Sarma NP Sonti RV | Journal: Biotechnol J Citation: V : 4 P : 400-7 Year: 2009 Type: In-Process | Literature: oryza Field: abstract Doc ID: pub19253322 Accession (PMID): 19253322 | Abstract: Bacterial blight ( BB ) is a serious disease of rice in India .
We have used molecular marker-assisted selection in a backcross breeding program to introgress three genes ( Xa21 , xa13 , and xa5 ) for BB resistance into Triguna , a mid-early duration , high yielding rice variety that is susceptible to BB .
At each generation in the backcross program , molecular markers were used to select plants possessing these resistance genes and to select plants that have maximum contribution from the Triguna genome .
A selected BC3F1 plant was selfed to generate homozygous BC ( 3 ) F ( 2 ) plants with different combinations of BB resistance genes .
Plants containing the two-gene combination , Xa21 and xa13 , were found to exhibit excellent resistance against BB .
Single plant selections for superior agronomic characteristics were performed on the progeny of these plants , from BC ( 3 ) F ( 3 ) generation onwards .
The selected plants were subjected to yield trials at the BC ( 3 ) F ( 8 ) generation and were found to have a significant yield advantage over Triguna .
The newly developed lines are being entered into national multi-location field trials .
This work represents a successful example of the application of molecular marker-assisted selection for BB resistance breeding in rice .
| Matching Sentences: [ Sen. 2, subscore: 1.00 ]: Bacterial blight ( BB ) is a serious disease of rice in India . We have used molecular marker-assisted selection in a backcross breeding program to introgress three genes ( Xa21 , xa13 , and xa5 ) for BB resistance into Triguna , a mid-early duration , high yielding rice variety that is susceptible to BB . At each generation in the backcross program , molecular markers were used to select plants possessing these resistance genes and to select plants that have maximum contribution from the Triguna genome . A selected BC3F1 plant was selfed to generate homozygous BC ( 3 ) F ( 2 ) plants with different combinations of BB resistance genes . Plants containing the two-gene combination , Xa21 and xa13 , were found to exhibit excellent resistance against BB . Single plant selections for superior agronomic characteristics were performed on the progeny of these plants , from BC ( 3 ) F ( 3 ) generation onwards . [ Sen. 5, subscore: 1.00 ]: Bacterial blight ( BB ) is a serious disease of rice in India . We have used molecular marker-assisted selection in a backcross breeding program to introgress three genes ( Xa21 , xa13 , and xa5 ) for BB resistance into Triguna , a mid-early duration , high yielding rice variety that is susceptible to BB . At each generation in the backcross program , molecular markers were used to select plants possessing these resistance genes and to select plants that have maximum contribution from the Triguna genome . A selected BC3F1 plant was selfed to generate homozygous BC ( 3 ) F ( 2 ) plants with different combinations of BB resistance genes . Plants containing the two-gene combination , Xa21 and xa13 , were found to exhibit excellent resistance against BB . Single plant selections for superior agronomic characteristics were performed on the progeny of these plants , from BC ( 3 ) F ( 3 ) generation onwards . The selected plants were subjected to yield trials at the BC ( 3 ) F ( 8 ) generation and were found to have a significant yield advantage over Triguna . The newly developed lines are being entered into national multi-location field trials . This work represents a successful example of the application of molecular marker-assisted selection for BB resistance breeding in rice .
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