Article

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.

Laboratory of Plant Resistasnce and Genetics, College of Resources and Environmental Sciences, South China Agricultural University, Guangzhou 510642, China.
Genetics (Impact Factor: 4.39). 09/2007; 176(4):2541-9. DOI: 10.1534/genetics.107.075465
Source: PubMed

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.

1 Bookmark
 · 
76 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The Pi9 gene in rice confers resistance to strains of blast pathogen Magnaporthe oryzae. Pi9 is a typical broad spectrum resistance gene containing nucleotide binding site, leucine rich repeat family of sequences. In the present study, presence of the Pi9 gene in 47 rice germplasm accessions was determined using dominant sequence tagged site marker 195R-1/195F-1 derived from the Nbs2-Pi9 candidate gene and resistance confirmed by inoculating rice germplasm with a mixture of aggressive isolates of M. oryzae namely Mo-ei-66, Mo-ei-79, Mo-ei-119, and Mo-ei-202. The Pi9 gene was found in six rice germplasm accessions from eastern India. Usefulness of this STS marker for determination of the genotype of rice germplasm was thus demonstrated. Rare occurrence of Pi9 gene in the evaluated rice germplasm suggests that its introgression is very less in indica rice. These results are useful for incorporating Pi9 gene into elite cultivars by marker assisted selection in rice breeding programs worldwide.
    Proceedings of the National Academy of Sciences, India - Section B: Biological Sciences 12/2013; · 0.40 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The dominant rice blast resistance gene Pi54 cloned by map-based cloning approach from indica rice cultivar Tetep confers broad spectrum resistance to Magnaporthe oryzae. In this investigation, an orthologue of Pi54 designated as Pi54of was cloned from Oryza officinalis conferring high degree of resistance to M. oryzae and is functionally validated. We have also characterized the Pi54of protein and demonstrate its interaction with AVR-Pi54 protein. The Pi54of encoded ∼43 kDa small and unique cytoplasmic LRR family of disease resistance protein having unique Zinc finger domain overlapped with the leucine rich repeat regions. Pi54of showed Magnaporthe-induced expression. The phylogenetic and western blot analysis confirmed orthologous nature of Pi54 and Pi54of genes, whereas the identity of protein was confirmed through MALDI-TOF analysis. The in silico analysis showed that Pi54of is structurally more stable than other cloned Pi54 proteins. The molecular docking revealed that Pi54of protein interacts with AVR-Pi54 through novel non-LRR domains such as STI1 and RhoGEF. The STI1 and GEF domains which interact with AVR-Pi54 are also components of rice defensome complex. The Pi54of protein showed differential domain specificity while interacting with the AVR protein. Functional complementation revealed that Pi54of transferred in two rice lines belonging to indica and japonica background imparts enhanced resistance against three highly virulent strains of M. oryzae. In this study, for the first time, we demonstrated that a rice blast resistance gene Pi54of cloned from wild species of rice provides high degree of resistance to M. oryzae and might display different molecular mechanism involved in AVRPi54-Pi54of interaction.
    PLoS ONE 01/2014; 9(8):e104840. · 3.53 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Bacterial leaf steak (BLS) is one of the most destructive diseases in rice. Studies have shown that BLS resistance in rice is quantitatively inherited, controlled by multiple quantitative trait loci (QTLs). A QTL with relatively large effect, qBlsr5a, was previously mapped in a region of ∼380 kb on chromosome 5. To fine map qBlsr5a further, a set of overlapping sub-chromosome segment substitution lines (sub-CSSLs) were developed from a large secondary F2 population (containing more than 7000 plants), in which only the chromosomal region harboring qBlsr5a was segregated. By genotyping the sub-CSSLs with molecular markers covering the target region and phenotyping the sub-CSSLs with artificial inoculation, qBlsr5a was delimited to a 30.0-kb interval, in which only three genes were predicted. qRT-PCR analysis indicated that the three putative genes did not show significant response to the infection of BLS pathogen in both resistant and susceptible parental lines. However, two nucleotide substitutions were found in the coding sequence of gene LOC_Os05g01710, which encodes the gamma chain of transcription initiation factor IIA (TFIIAγ). The nucleotide substitutions resulted in a change of the 39th amino acid from valine (in the susceptible parent) to glutamic acid (in the resistant parent). Interestingly, the resistant parent allele of LOC_Os05g01710 is identical to xa5, a major gene resistant to bacterial leaf blight (another bacterial disease of rice). These results suggest that LOC_Os05g01710 is very possibly the candidate gene of qBlsr5a.
    PLoS ONE 01/2014; 9(4):e95751. · 3.53 Impact Factor

Full-text

View
0 Downloads
Available from