| 30 matches found in 12 documents. Search time: 0.012 seconds. |
|---|
|
Score: 9.00 |
|---|
| Title: Two broad-spectrum blast resistance genes , Pi9 ( t ) and Pi2 ( t ) , are physically linked on rice chromosome 6 .
| | Author: Liu G Lu G Zeng L Wang GL .
| | Journal: Mol . Genet . Genomics Citation: V : 267 ( 4 ) P : 472-80 Year: 2002 Type: ARTICLE | | Literature: oryza Field: abstract Doc ID: pub12111554 Accession (PMID): 12111554 | | Abstract: To understand the molecular basis of broad-spectrum resistance to rice blast , fine-scale mapping of the two blast resistance ( R ) genes , Pi9 ( t ) and Pi2 ( t ) , was conducted .
These two genes were introgressed from different resistance donors , previously reported to confer resistance to many blast isolates in the Philippines , and were mapped to an approximately 10-cM interval on chromosome 6 .
To further test their resistance spectrum , 43 blast isolates collected from 13 countries were used to inoculate the Pi2 ( t ) and Pi9 ( t ) plants .
Pi9 ( t ) -bearing lines were highly resistant to all isolates tested , and lines carrying Pi2 ( t ) were resistant to 36 isolates , confirming the broad-spectrum resistance of these two genes to diverse blast isolates .
Three RAPD markers tightly linked to Pi9 ( t ) were identified using the bulk segregant analysis technique .
Twelve positive bacterial artificial chromosome ( BAC ) clones were identified and a BAC contig covering about 100 kb was constructed when the Pi9 ( t ) BAC library was screened with one of the markers .
A high-resolution map of Pi9 ( t ) was constructed using BAC ends .
The Pi2 ( t ) gene was tightly linked to all of the Pi9 ( t ) markers in 450 F ( 2 ) plants .
These data suggest that Pi9 ( t ) and Pi2 ( t ) are either allelic or tightly linked in an approximately 100-kb region .
The mapping results for Pi9 ( t ) and Pi2 ( t ) provide essential information for the positional cloning of these two important blast resistance genes in rice . | Matching Sentences:
[ Sen. 1, subscore: 1.00 ]: To understand the molecular basis of broad-spectrum resistance to rice blast , fine-scale mapping of the two blast resistance ( R ) genes , Pi9 ( t ) and Pi2 ( t ) , was conducted .
[ Sen. 3, subscore: 1.00 ]: To further test their resistance spectrum , 43 blast isolates collected from 13 countries were used to inoculate the Pi2 ( t ) and Pi9 ( t ) plants .
[ Sen. 4, subscore: 1.00 ]: Pi9 ( t ) -bearing lines were highly resistant to all isolates tested , and lines carrying Pi2 ( t ) were resistant to 36 isolates , confirming the broad-spectrum resistance of these two genes to diverse blast isolates .
[ Sen. 5, subscore: 1.00 ]: Three RAPD markers tightly linked to Pi9 ( t ) were identified using the bulk segregant analysis technique .
[ Sen. 6, subscore: 1.00 ]: Twelve positive bacterial artificial chromosome ( BAC ) clones were identified and a BAC contig covering about 100 kb was constructed when the Pi9 ( t ) BAC library was screened with one of the markers .
[ Sen. 7, subscore: 1.00 ]: A high-resolution map of Pi9 ( t ) was constructed using BAC ends .
[ Sen. 8, subscore: 1.00 ]: The Pi2 ( t ) gene was tightly linked to all of the Pi9 ( t ) markers in 450 F ( 2 ) plants .
[ Sen. 9, subscore: 1.00 ]: These data suggest that Pi9 ( t ) and Pi2 ( t ) are either allelic or tightly linked in an approximately 100-kb region .
[ Sen. 10, subscore: 1.00 ]: The mapping results for Pi9 ( t ) and Pi2 ( t ) provide essential information for the positional cloning of these two important blast resistance genes in rice .
| | Supplemental links/files: reference in endnote online text related articles pubmed citation | |
Score: 9.00 |
|---|
| Title: The broad-spectrum blast resistance gene Pi9 encodes a nucleotide-binding site-leucine-rich repeat protein and is a member of a multigene family in rice .
| | Author: Qu S Liu G Zhou B Bellizzi M Zeng L Dai L Han B Wang GL .
| | Journal: Genetics Citation: V : 172 ( 3 ) P : 1901-14 Year: 2006 Type: ARTICLE | | Literature: oryza Field: abstract Doc ID: pub16387888 Accession (PMID): 16387888 | | Abstract: The broad-spectrum rice blast resistance gene Pi9 was cloned using a map-based cloning strategy .
Sequencing of a 76-kb bacterial artificial chromosome ( BAC ) contig spanning the Pi9 locus led to identification of six tandemly arranged resistance-like genes with a nucleotide-binding site ( NBS ) and leucine-rich repeats ( LRRs ) ( Nbs1-Pi9-Nbs6-Pi9 ) .
Analysis of selected Pi9 deletion mutants and transformation of a 45-kb fragment from the BAC contig into the susceptible rice cultivar TP309 narrowed down Pi9 to the candidate genes Nbs2-Pi9 and Nbs3-Pi9 .
Disease evaluation of the transgenic lines carrying the individual candidate genes confirmed that Nbs2-Pi9 is the Pi9 gene .
Sequence comparison analysis revealed that the six paralogs at the Pi9 locus belong to four classes and gene duplication might be one of the major evolutionary forces contributing to the formation of the NBS-LRR gene cluster .
Semiquantitative reverse transcriptase ( RT ) -PCR analysis showed that Pi9 was constitutively expressed in the Pi9-resistant plants and was not induced by blast infection .
The cloned Pi9 gene provides a starting point to elucidate the molecular basis of the broad-spectrum disease resistance and the evolutionary mechanisms of blast resistance gene clusters in rice .
| Matching Sentences:
[ Sen. 3, subscore: 2.00 ]: Analysis of selected Pi9 deletion mutants and transformation of a 45-kb fragment from the BAC contig into the susceptible rice cultivar TP309 narrowed down Pi9 to the candidate genes Nbs2-Pi9 and Nbs3-Pi9 .
[ Sen. 6, subscore: 2.00 ]: Semiquantitative reverse transcriptase ( RT ) -PCR analysis showed that Pi9 was constitutively expressed in the Pi9-resistant plants and was not induced by blast infection .
[ Sen. 1, subscore: 1.00 ]: The broad-spectrum rice blast resistance gene Pi9 was cloned using a map-based cloning strategy .
[ Sen. 2, subscore: 1.00 ]: Sequencing of a 76-kb bacterial artificial chromosome ( BAC ) contig spanning the Pi9 locus led to identification of six tandemly arranged resistance-like genes with a nucleotide-binding site ( NBS ) and leucine-rich repeats ( LRRs ) ( Nbs1-Pi9-Nbs6-Pi9 ) .
[ Sen. 4, subscore: 1.00 ]: Disease evaluation of the transgenic lines carrying the individual candidate genes confirmed that Nbs2-Pi9 is the Pi9 gene .
[ Sen. 5, subscore: 1.00 ]: Sequence comparison analysis revealed that the six paralogs at the Pi9 locus belong to four classes and gene duplication might be one of the major evolutionary forces contributing to the formation of the NBS-LRR gene cluster .
[ Sen. 7, subscore: 1.00 ]: The cloned Pi9 gene provides a starting point to elucidate the molecular basis of the broad-spectrum disease resistance and the evolutionary mechanisms of blast resistance gene clusters in rice .
| | Supplemental links/files: reference in endnote online text related articles pubmed citation | |
Score: 4.00 |
|---|
| Title: Genomic structure and evolution of the Pi2/9 locus in wild rice species .
| | Author: Dai L Wu J Li X Wang X Liu X Jantasuriyarat C Kudrna D Yu Y Wing RA Han B Zhou B Wang GL | | Journal: Theor Appl Genet Citation: V : 121 P : 295-309 Year: 2010 Type: MEDLINE | | Literature: oryza Field: abstract Doc ID: pub20229250 Accession (PMID): 20229250 | | Abstract: Rice blast , caused by the fungal pathogen Magnaporthe oryzae , is a devastating disease of rice worldwide .
Among the 85 mapped resistance ( R ) genes against blast , 13 have been cloned and characterized .
However , how these genes originated and how they evolved in the Oryza genus remains unclear .
We previously cloned the rice blast R-genes Pi2 , Pi9 , and Piz-t , and analyzed their genomic structure and evolution in cultivated rice .
In this study , we determined the genomic sequences of the Pi2/9 locus in four wild Oryza species representing three genomes ( AA , BB and CC ) .
The number of Pi2/9 family members in the four wild species ranges from two copies to 12 copies .
Although these genes are conserved in structure and categorized into the same subfamily , sequence duplications and subsequent inversions or uneven crossing overs were observed , suggesting that the locus in different wild species has undergone dynamic changes .
Positive selection was found in the leucine-rich repeat region of most members , especially in the largest clade where Pi9 is included .
We also provide evidence that the Pi9 gene is more related to its homologues in the recurrent line and other rice cultivars than to those in its alleged donor species O minuta , indicating a possible origin of the Pi9 gene from O sativa .
Comparative sequence analysis between the four wild Oryza species and the previously established reference sequences in cultivated rice species at the Pi2/9 locus has provided extensive and unique information on the genomic structure and evolution of a complex R-gene cluster in the Oryza genus .
| Matching Sentences:
[ Sen. 9, subscore: 2.00 ]: We also provide evidence that the Pi9 gene is more related to its homologues in the recurrent line and other rice cultivars than to those in its alleged donor species O minuta , indicating a possible origin of the Pi9 gene from O sativa .
[ Sen. 4, subscore: 1.00 ]: We previously cloned the rice blast R-genes Pi2 , Pi9 , and Piz-t , and analyzed their genomic structure and evolution in cultivated rice .
[ Sen. 8, subscore: 1.00 ]: Positive selection was found in the leucine-rich repeat region of most members , especially in the largest clade where Pi9 is included .
| | Supplemental links/files: reference in endnote online text related articles pubmed citation | |
Score: 3.00 |
|---|
| Title: Genetic characterization and fine mapping of the blast resistance locus Pigm ( t ) tightly linked to Pi2 and Pi9 in a broad-spectrum resistant Chinese variety .
| | Author: Deng Y Zhu X Shen Y He Z | | Journal: Theor . Appl . Genet . Citation: V : 113 ( 4 ) P : 705-13 Year: 2006 Type: ARTICLE | | Literature: oryza Field: abstract Doc ID: pub16832648 Accession (PMID): 16832648 | | Abstract: The identification and utilization of broad-spectrum resistance genes have been proven the most effective and economical approach to control rice blast disease .
To understand the molecular mechanism of broad-spectrum resistance to rice blast , we conducted genetic and fine mapping analysis of the blast resistance gene in a Chinese rice variety : Gumei 4 ( GM4 ) identified with broad-spectrum resistance and used in rice breeding for blast resistance for more than 20 years .
Genetic and mapping analysis indicated that blast resistance to nine isolates of different Chinese races in GM4 was controlled by the same dominant locus designated as Pigm ( t ) that was finely mapped to an approximately 70-kb interval between markers C5483 and C0428 on chromosome 6 , which contains five candidate NBS--LRR disease resistance genes .
The allelism test showed that Pigm ( t ) was either tightly linked or allelic to Pi2 and Pi9 , two known blast resistance genes .
Mapping information also indicated that another blast resistance gene Pi26 ( t ) might also be located at the same region .
Candidate genes were identified by sequence analysis of the Nipponbare and Pi9 locus and the corresponding region in GM4 .
Sequence divergence of candidate genes was observed between GM4 and model varieties Nipponbare and 9311 , and Pi9 .
Our current study provides essential information and new genetic resource for the cloning of functional resistance gene ( s ) and for marker-assisted selection in rice breeding for broad-spectrum blast resistance . | Matching Sentences:
[ Sen. 4, subscore: 1.00 ]: The allelism test showed that Pigm ( t ) was either tightly linked or allelic to Pi2 and Pi9 , two known blast resistance genes .
[ Sen. 6, subscore: 1.00 ]: Candidate genes were identified by sequence analysis of the Nipponbare and Pi9 locus and the corresponding region in GM4 .
[ Sen. 7, subscore: 1.00 ]: Sequence divergence of candidate genes was observed between GM4 and model varieties Nipponbare and 9311 , and Pi9 .
| | Supplemental links/files: reference in endnote online text related articles pubmed citation | |
Score: 1.00 |
|---|
| Title: Isolation and characterization of novel defense response genes involved in compatible and incompatible interactions between rice and Magnaporthe grisea .
| | Author: Lu G Jantasuriyarat C Zhou B Wang GL .
| | Journal: Theor . Appl . Genet . Citation: V : 108 ( 3 ) P : 525-34 Year: 2004 Type: ARTICLE | | Literature: oryza Field: abstract Doc ID: pub14605807 Accession (PMID): 14605807 | | Abstract: To identify early-induced defense genes involved in broad-spectrum resistance to rice blast , suppression subtractive hybridization was used to generate two cDNA libraries enriched for transcripts differentially expressed in Pi9 ( t ) -resistant and -susceptible plants .
After differential screening by membrane-based hybridization and subsequent confirmation by reverse Northern blot analysis , selected clones were sequenced and analyzed .
Forty-seven unique cDNA clones were found and assigned to eight different groups according to the putative function of their homologous genes in the database .
These genes may be involved in pathogen or stress response , signal transduction , transcription , cell transport , metabolism , energy or protein destination .
Northern blot analysis showed that most of these genes were induced or suppressed after blast infection , and that half of them showed differential expression patterns between compatible and incompatible interactions .
Interestingly , all but one of the identified genes are reported here for the first time to be involved in defense response to rice blast In addition , hybridization of these clones with cDNAs synthesized from RNA samples from bacterial blight-infected leaves showed that few of them are induced or repressed in Xa21 or Xa7-resistant plants , suggesting a minimum overlap of defense responses mediated by different resistance genes to fungal and bacterial pathogens at an early stage of infection .
Further characterization and functional analysis of these genes will enhance our understanding of the molecular mechanism of broad-spectrum resistance in rice . | Matching Sentences:
[ Sen. 1, subscore: 1.00 ]: To identify early-induced defense genes involved in broad-spectrum resistance to rice blast , suppression subtractive hybridization was used to generate two cDNA libraries enriched for transcripts differentially expressed in Pi9 ( t ) -resistant and -susceptible plants .
| | Supplemental links/files: reference in endnote online text related articles pubmed citation | |
Score: 1.00 |
|---|
| Title: The in silico map-based cloning of Pi36 , a rice coiled-coil nucleotide-binding site leucine-rich repeat gene that confers race-specific resistance to the blast fungus .
| | Author: Liu X Lin F Wang L Pan Q | | Journal: Genetics Citation: V : 176 P : Sep-41 Year: 2007 Type: MEDLINE | | Literature: oryza Field: abstract Doc ID: pub17507669 Accession (PMID): 17507669 | | Abstract: The indica rice variety Kasalath carries Pi36 , a gene that determines resistance to Chinese isolates of rice blast and that has been located to a 17-kb interval on chromosome 8 .
The genomic sequence of the reference japonica variety Nipponbare was used for an in silico prediction of the resistance ( R ) gene content of the interval and hence for the identification of candidate gene ( s ) for Pi36 .
Three such sequences , which all had both a nucleotide-binding site and a leucine-rich repeat motif , were present .
The three candidate genes were amplified from the genomic DNA of a number of varieties by long-range PCR , and the resulting amplicons were inserted into pCAMBIA1300 and/or pYLTAC27 vectors to determine sequence polymorphisms correlated to the resistance phenotype and to perform transgenic complementation tests .
Constructs containing each candidate gene were transformed into the blast-susceptible variety Q1063 , which allowed the identification of Pi36-3 as the functional gene , with the other two candidates being probable pseudogenes .
The Pi36-encoded protein is composed of 1056 amino acids , with a single substitution event ( Asp to Ser ) at residue 590 associated with the resistant phenotype .
Pi36 is a single-copy gene in rice and is more closely related to the barley powdery mildew resistance genes Mla1 and Mla6 than to the rice blast R genes Pita , Pib , Pi9 , and Piz-t .
An RT-PCR analysis showed that Pi36 is constitutively expressed in Kasalath .
| Matching Sentences:
[ Sen. 7, subscore: 1.00 ]: Pi36 is a single-copy gene in rice and is more closely related to the barley powdery mildew resistance genes Mla1 and Mla6 than to the rice blast R genes Pita , Pib , Pi9 , and Piz-t .
| | Supplemental links/files: reference in endnote online text related articles pubmed citation | |
Score: 1.00 |
|---|
| Title: A novel gene , Pi40 ( t ) , linked to the DNA markers derived from NBS-LRR motifs confers broad spectrum of blast resistance in rice .
| | Author: Jeung JU Kim BR Cho YC Han SS Moon HP Lee YT Jena KK | | Journal: Theor Appl Genet Citation: V : 115 P : 1163-77 Year: 2007 Type: MEDLINE | | Literature: oryza Field: abstract Doc ID: pub17909744 Accession (PMID): 17909744 | | Abstract: Rice blast disease caused by Magnaporthe grisea is a continuous threat to stable rice production worldwide .
In a modernized agricultural system , the development of varieties with broad-spectrum and durable resistance to blast disease is essential for increased rice production and sustainability .
In this study , a new gene is identified in the introgression line IR65482-4-136-2-2 that has inherited the resistance gene from an EE genome wild Oryza species , O australiensis ( Acc .
100882 ) .
Genetic and molecular analysis localized a major resistance gene , Pi40 ( t ) , on the short arm of chromosome 6 , where four blast resistance genes ( Piz , Piz-5 , Piz-t , and Pi9 ) were also identified , flanked by the markers S2539 and RM3330 .
Through e-Landing , 14 BAC/PAC clones within the 1 . 81-Mb equivalent virtual contig were identified on Rice Pseudomolecule3 .
Highly stringent primer sets designed for 6 NBS-LRR motifs located within PAC clone P0649C11 facilitated high-resolution mapping of the new resistance gene , Pi40 ( t ) .
Following association analysis and detailed haplotyping approaches , a DNA marker , 9871 . T7E2b , was identified to be linked to the Pi40 ( t ) gene at the 70 Kb chromosomal region , and differentiated the Pi40 ( t ) gene from the LTH monogenic differential lines possessing genes Piz , Piz-5 , Piz-t , and Pi-9 .
Pi40 ( t ) was validated using the most virulent isolates of Korea as well as the Philippines , suggesting a broad spectrum for the resistance gene .
Marker-assisted selection ( MAS ) and pathotyping of BC progenies having two japonica cultivar genetic backgrounds further supported the potential of the resistance gene in rice breeding .
Our study based on new gene identification strategies provides insight into novel genetic resources for blast resistance as well as future studies on cloning and functional analysis of a blast resistance gene useful for rice improvement .
| Matching Sentences:
[ Sen. 5, subscore: 1.00 ]: Genetic and molecular analysis localized a major resistance gene , Pi40 ( t ) , on the short arm of chromosome 6 , where four blast resistance genes ( Piz , Piz-5 , Piz-t , and Pi9 ) were also identified , flanked by the markers S2539 and RM3330 .
| | Supplemental links/files: reference in endnote online text related articles pubmed citation | |
Score: 1.00 |
|---|
| Title: The blast resistance gene Pi37 encodes a nucleotide binding site leucine-rich repeat protein and is a member of a resistance gene cluster on rice chromosome 1 .
| | Author: Lin F Chen S Que Z Wang L Liu X Pan Q | | Journal: Genetics Citation: V : 177 P : 1871-80 Year: 2007 Type: MEDLINE | | Literature: oryza Field: abstract Doc ID: pub17947408 Accession (PMID): 17947408 | | Abstract: The resistance ( R ) gene Pi37 , present in the rice cultivar St No 1 , was isolated by an in silico map-based cloning procedure .
The equivalent genetic region in Nipponbare contains four nucleotide binding site-leucine-rich repeat ( NBS-LRR ) type loci .
These four candidates for Pi37 ( Pi37-1 , -2 , -3 , and -4 ) were amplified separately from St No 1 via long-range PCR , and cloned into a binary vector .
Each construct was individually transformed into the highly blast susceptible cultivar Q1063 .
The subsequent complementation analysis revealed Pi37-3 to be the functional gene , while -1 , -2 , and -4 are probably pseudogenes .
Pi37 encodes a 1290 peptide NBS-LRR product , and the presence of substitutions at two sites in the NBS region ( V239A and I247M ) is associated with the resistance phenotype .
Semiquantitative expression analysis showed that in St No 1 , Pi37 was constitutively expressed and only slightly induced by blast infection .
Transient expression experiments indicated that the Pi37 product is restricted to the cytoplasm .
Pi37-3 is thought to have evolved recently from -2 , which in turn was derived from an ancestral -1 sequence .
Pi37-4 is likely the most recently evolved member of the cluster and probably represents a duplication of -3 .
The four Pi37 paralogs are more closely related to maize rp1 than to any of the currently isolated rice blast R genes Pita , Pib , Pi9 , Pi2 , Piz-t , and Pi36 .
| Matching Sentences:
[ Sen. 11, subscore: 1.00 ]: The four Pi37 paralogs are more closely related to maize rp1 than to any of the currently isolated rice blast R genes Pita , Pib , Pi9 , Pi2 , Piz-t , and Pi36 .
| | Supplemental links/files: reference in endnote online text related articles pubmed citation | |
Score: 1.00 |
|---|
| Title: The pi40 gene for durable resistance to rice blast and molecular analysis of pi40-advanced backcross breeding lines .
| | Author: Suh JP Roh JH Cho YC Han SS Kim YG Jena KK | | Journal: Phytopathology Citation: V : 99 P : 243-50 Year: 2009 Type: MEDLINE | | Literature: oryza Field: abstract Doc ID: pub19203276 Accession (PMID): 19203276 | | Abstract: Rice blast severely reduces production in both irrigated and water-stressed upland ecosystems of tropical and temperate countries .
Nearly 50 blast resistance genes have been identified and some of those are incorporated into several rice cultivars .
However , most of the resistance genes break down in a few years because of their race specificity and the rapid change in pathogenicity of the blast fungus ( Magnaporthe grisea ) .
The objective of this study was to analyze advanced backcross breeding lines ( ABL ) possessing the gene Pi40 for durable rice blast resistance .
In all , 4 resistant genotypes , 4 japonica cultivars , and 10 monogenic differential rice genotypes with some known resistance genes were bioassayed in the greenhouse using seven sequential plantings and 29 virulent M grisea isolates of Korea .
The genotypes with the Pi40 gene had <3% diseased leaf area , which was significantly below the disease threshold level of 40% considered for durable blast resistance .
Moreover , the genotypes with the Pi40 gene expressed compatibility with only two to three virulent M grisea isolates supporting durability of resistance , in contrast to susceptible cultivars with >50% diseased leaf area and 10 compatible isolates .
Of the 10 known resistance genes tested , Piz-t , Piz-5 , and Pi9 showed differential reactions to the pathogen isolates in seven plantings .
Genotyping of the ABL with 260 simple sequence repeat ( SSR ) markers revealed rapid conversion toward recurrent parent genotypes with fewer donor chromosomal segments ( 5 . 3 to 14 . 5% ) .
Our study based on a sequential testing and background selection of breeding lines with the resistance gene Pi40 provided valuable information for durable blast resistance breeding in rice .
| Matching Sentences:
[ Sen. 8, subscore: 1.00 ]: Of the 10 known resistance genes tested , Piz-t , Piz-5 , and Pi9 showed differential reactions to the pathogen isolates in seven plantings .
| | Supplemental links/files: reference in endnote online text related articles pubmed citation | |
Score: 1.00 |
|---|
| Title: Two broad-spectrum blast resistance genes , Pi9 ( t ) and Pi2 ( t ) , are physically linked on rice chromosome 6 .
| | Author: Liu G Lu G Zeng L Wang GL .
| | Journal: Mol . Genet . Genomics Citation: V : 267 ( 4 ) P : 472-80 Year: 2002 Type: ARTICLE | | Literature: oryza Field: title Doc ID: pub12111554 Accession (PMID): 12111554 | | Abstract: To understand the molecular basis of broad-spectrum resistance to rice blast , fine-scale mapping of the two blast resistance ( R ) genes , Pi9 ( t ) and Pi2 ( t ) , was conducted .
These two genes were introgressed from different resistance donors , previously reported to confer resistance to many blast isolates in the Philippines , and were mapped to an approximately 10-cM interval on chromosome 6 .
To further test their resistance spectrum , 43 blast isolates collected from 13 countries were used to inoculate the Pi2 ( t ) and Pi9 ( t ) plants .
Pi9 ( t ) -bearing lines were highly resistant to all isolates tested , and lines carrying Pi2 ( t ) were resistant to 36 isolates , confirming the broad-spectrum resistance of these two genes to diverse blast isolates .
Three RAPD markers tightly linked to Pi9 ( t ) were identified using the bulk segregant analysis technique .
Twelve positive bacterial artificial chromosome ( BAC ) clones were identified and a BAC contig covering about 100 kb was constructed when the Pi9 ( t ) BAC library was screened with one of the markers .
A high-resolution map of Pi9 ( t ) was constructed using BAC ends .
The Pi2 ( t ) gene was tightly linked to all of the Pi9 ( t ) markers in 450 F ( 2 ) plants .
These data suggest that Pi9 ( t ) and Pi2 ( t ) are either allelic or tightly linked in an approximately 100-kb region .
The mapping results for Pi9 ( t ) and Pi2 ( t ) provide essential information for the positional cloning of these two important blast resistance genes in rice . | Matching Sentences:
[ Sen. 1, subscore: 1.00 ]: Two broad-spectrum blast resistance genes , Pi9 ( t ) and Pi2 ( t ) , are physically linked on rice chromosome 6 .
| | Supplemental links/files: reference in endnote online text related articles pubmed citation | |
Score: 1.00 |
|---|
| Title: The broad-spectrum blast resistance gene Pi9 encodes a nucleotide-binding site-leucine-rich repeat protein and is a member of a multigene family in rice .
| | Author: Qu S Liu G Zhou B Bellizzi M Zeng L Dai L Han B Wang GL .
| | Journal: Genetics Citation: V : 172 ( 3 ) P : 1901-14 Year: 2006 Type: ARTICLE | | Literature: oryza Field: title Doc ID: pub16387888 Accession (PMID): 16387888 | | Abstract: The broad-spectrum rice blast resistance gene Pi9 was cloned using a map-based cloning strategy .
Sequencing of a 76-kb bacterial artificial chromosome ( BAC ) contig spanning the Pi9 locus led to identification of six tandemly arranged resistance-like genes with a nucleotide-binding site ( NBS ) and leucine-rich repeats ( LRRs ) ( Nbs1-Pi9-Nbs6-Pi9 ) .
Analysis of selected Pi9 deletion mutants and transformation of a 45-kb fragment from the BAC contig into the susceptible rice cultivar TP309 narrowed down Pi9 to the candidate genes Nbs2-Pi9 and Nbs3-Pi9 .
Disease evaluation of the transgenic lines carrying the individual candidate genes confirmed that Nbs2-Pi9 is the Pi9 gene .
Sequence comparison analysis revealed that the six paralogs at the Pi9 locus belong to four classes and gene duplication might be one of the major evolutionary forces contributing to the formation of the NBS-LRR gene cluster .
Semiquantitative reverse transcriptase ( RT ) -PCR analysis showed that Pi9 was constitutively expressed in the Pi9-resistant plants and was not induced by blast infection .
The cloned Pi9 gene provides a starting point to elucidate the molecular basis of the broad-spectrum disease resistance and the evolutionary mechanisms of blast resistance gene clusters in rice .
| Matching Sentences:
[ Sen. 1, subscore: 1.00 ]: The broad-spectrum blast resistance gene Pi9 encodes a nucleotide-binding site-leucine-rich repeat protein and is a member of a multigene family in rice .
| | Supplemental links/files: reference in endnote online text related articles pubmed citation | |
Score: 1.00 |
|---|
| Title: Genetic characterization and fine mapping of the blast resistance locus Pigm ( t ) tightly linked to Pi2 and Pi9 in a broad-spectrum resistant Chinese variety .
| | Author: Deng Y Zhu X Shen Y He Z | | Journal: Theor . Appl . Genet . Citation: V : 113 ( 4 ) P : 705-13 Year: 2006 Type: ARTICLE | | Literature: oryza Field: title Doc ID: pub16832648 Accession (PMID): 16832648 | | Abstract: The identification and utilization of broad-spectrum resistance genes have been proven the most effective and economical approach to control rice blast disease .
To understand the molecular mechanism of broad-spectrum resistance to rice blast , we conducted genetic and fine mapping analysis of the blast resistance gene in a Chinese rice variety : Gumei 4 ( GM4 ) identified with broad-spectrum resistance and used in rice breeding for blast resistance for more than 20 years .
Genetic and mapping analysis indicated that blast resistance to nine isolates of different Chinese races in GM4 was controlled by the same dominant locus designated as Pigm ( t ) that was finely mapped to an approximately 70-kb interval between markers C5483 and C0428 on chromosome 6 , which contains five candidate NBS--LRR disease resistance genes .
The allelism test showed that Pigm ( t ) was either tightly linked or allelic to Pi2 and Pi9 , two known blast resistance genes .
Mapping information also indicated that another blast resistance gene Pi26 ( t ) might also be located at the same region .
Candidate genes were identified by sequence analysis of the Nipponbare and Pi9 locus and the corresponding region in GM4 .
Sequence divergence of candidate genes was observed between GM4 and model varieties Nipponbare and 9311 , and Pi9 .
Our current study provides essential information and new genetic resource for the cloning of functional resistance gene ( s ) and for marker-assisted selection in rice breeding for broad-spectrum blast resistance . | Matching Sentences:
[ Sen. 1, subscore: 1.00 ]: Genetic characterization and fine mapping of the blast resistance locus Pigm ( t ) tightly linked to Pi2 and Pi9 in a broad-spectrum resistant Chinese variety .
| | Supplemental links/files: reference in endnote online text related articles pubmed citation | |
