title: Cloning of novel rice blast resistance genes from two rapidly evolving NBS-LRR gene families in rice.
abstract: Most rice blast resistance genes (R-genes) encode proteins with nucleotide-binding site (NBS) and leucine-rich repeat (LRR) domains. Our previous study has shown that more rice blast R-genes can be cloned in rapidly evolving NBS-LRR gene families. In the present study, two rapidly evolving R-gene families in rice were selected for cloning a subset of genes from their paralogs in three resistant rice lines. A total of eight functional blast R-genes were identified among nine NBS-LRR genes, and some of these showed resistance to three or more blast strains. Evolutionary analysis indicated that high nucleotide diversity of coding regions served as important parameters in the determination of gene resistance. We also observed that amino-acid variants (nonsynonymous mutations, insertions, or deletions) in essential motifs of the NBS domain contribute to the blast resistance capacity of NBS-LRR genes. These results suggested that the NBS regions might also play an important role in resistance specificity determination. On the other hand, different splicing patterns of introns were commonly observed in R-genes. The results of the present study contribute to improving the effectiveness of R-gene identification by using evolutionary analysis method and acquisition of novel blast resistance genes.
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, 210023, China.
authors.forename: Changjiang
authors.initials: C
authors.lastname: Guo
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, 210023, China.
authors.forename: Xiaoguang
authors.initials: X
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, 210023, China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, 210023, China.
authors.forename: Sihai
authors.initials: S
authors.lastname: Yang
authors.affiliation: Institute for Research on Cancer and Ageing, Nice (IRCAN), University of Nice, Nice, France.
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, 210023, China. wanglong@nju.edu.cn.
authors.forename: Long
authors.initials: L
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, 210023, China. xiaohuizhang@nju.edu.cn.
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Zhang
mesh_terms: D001665:Binding Sites; D003001:Cloning, Molecular; D060467:Disease Resistance; D007930:Leucine; D020082:Magnaporthe / Q000502:physiology*; D005810:Multigene Family; D012275:Oryza / Q000235:genetics* / Q000276:immunology / Q000382:microbiology; D010802:Phylogeny; D010935:Plant Diseases / Q000276:immunology* / Q000382:microbiology; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment
chemical_list: D010940:Plant Proteins; D007930:Leucine
keywords: K a /K s; NBS-LRR; Nucleotide diversity; Resistance gene; Rice blast