| 30 matches found in 12 documents. Search time: 0.009 seconds. |
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Score: 9.00 |
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| 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 .
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Score: 9.00 |
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| 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 .
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[ 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 .
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Score: 4.00 |
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| 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 .
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[ 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 |
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| 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 |
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| 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 | |
