title: A genome-wide survey reveals abundant rice blast R genes in resistant cultivars.
abstract: Plant resistance genes (R genes) harbor tremendous allelic diversity, constituting a robust immune system effective against microbial pathogens. Nevertheless, few functional R genes have been identified for even the best-studied pathosystems. Does this limited repertoire reflect specificity, with most R genes having been defeated by former pests, or do plants harbor a rich diversity of functional R genes, the composite behavior of which is yet to be characterized? Here, we survey 332 NBS-LRR genes cloned from five resistant Oryza sativa (rice) cultivars for their ability to confer recognition of 12 rice blast isolates when transformed into susceptible cultivars. Our survey reveals that 48.5% of the 132 NBS-LRR loci tested contain functional rice blast R genes, with most R genes deriving from multi-copy clades containing especially diversified loci. Each R gene recognized, on average, 2.42 of the 12 isolates screened. The abundant R genes identified in resistant genomes provide extraordinary redundancy in the ability of host genotypes to recognize particular isolates. If the same is true for other pathogens, many extant NBS-LRR genes retain functionality. Our success at identifying rice blast R genes also validates a highly efficient cloning and screening strategy.
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, Department of Biology, Nanjing Agricultural University, Nanjing 210023, China.
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, Department of Biology, Nanjing Agricultural University, Nanjing 210023, China.
authors.forename: Sihai
authors.initials: S
authors.lastname: Yang
authors.affiliation: National Center for Soybean Improvement, National Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Jiao
authors.initials: J
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, Department of Biology, Nanjing Agricultural University, Nanjing 210023, China.
authors.forename: Yanxiao
authors.initials: Y
authors.lastname: Jia
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, Department of Biology, Nanjing Agricultural University, Nanjing 210023, China.
authors.forename: Ju
authors.initials: J
authors.lastname: Huang
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, Department of Biology, Nanjing Agricultural University, Nanjing 210023, China.
authors.forename: Shengjun
authors.initials: S
authors.lastname: Tan
authors.affiliation: College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhong
authors.affiliation: State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, South China Agricultural University, Guangzhou, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, Department of Biology, Nanjing Agricultural University, Nanjing 210023, China.
authors.forename: Longjiang
authors.initials: L
authors.lastname: Gu
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, Department of Biology, Nanjing Agricultural University, Nanjing 210023, China.
authors.forename: Jian-Qun
authors.initials: JQ
authors.lastname: Chen
authors.affiliation: State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, South China Agricultural University, Guangzhou, China.
authors.forename: Qinghua
authors.initials: Q
authors.lastname: Pan
authors.affiliation: Department of Ecology & Evolution, University of Chicago, Chicago, USA.
authors.forename: Joy
authors.initials: J
authors.lastname: Bergelson
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, Department of Biology, Nanjing Agricultural University, Nanjing 210023, China.
authors.forename: Dacheng
authors.initials: D
authors.lastname: Tian
mesh_terms: D060467:Disease Resistance / Q000235:genetics*; D055106:Genome-Wide Association Study; D020082:Magnaporthe / Q000502:physiology; D012275:Oryza / Q000235:genetics* / Q000382:microbiology; D010940:Plant Proteins / Q000235:genetics*; D017422:Sequence Analysis, DNA
chemical_list: D010940:Plant Proteins
keywords: Magnaporthe oryzae; Oryza sativa; genome-wide survey; plant resistance genes; rice blast