title: Characterization and fine mapping of a light-dependent leaf lesion mimic mutant 1 in rice.
abstract: Plants that spontaneously produce lesion mimics or spots, without any signs of obvious adversity, such as pesticide and mechanical damage, or pathogen infection, are so-called lesion mimic mutants (lmms). In rice, many lmms exhibit enhanced resistance to pathogens, which provides a unique opportunity to uncover the molecular mechanism underlying lmms. We isolated a rice light-dependent leaf lesion mimic mutant 1 (llm1). Lesion spots appeared in the leaves of the llm1 mutant at the tillering stage. Furthermore, the mutant llm1 had similar agronomic traits to wild type rice. Trypan blue and diamiobenzidine staining analyses revealed that the lesion spot formation on the llm1 mutant was due to programmed cell death and reactive oxygen species. The chloroplasts were severely damaged in the llm1 mutant, suggesting that chloroplast damage was associated with the formation of lesion spots in llm1. More importantly, llm1 exhibited enhanced resistance to bacterial blight pathogens within increased expression of pathogenesis related genes (PRs). Using a map-based cloning approach, we delimited the LLM1 locus to a 121-kb interval between two simple sequence repeat markers, RM17470 and RM17473, on chromosome 4. We sequenced the candidate genes on the interval and found that a base mutation had substituted adenine phosphate for thymine in the last exon of LOC_Os04g52130, which led to an amino acid change (Asp(388) to Val) in the llm1 mutant. Our investigation showed that the putative coproporphyrinogen III oxidase (CPOX) encoded by LOC_Os04g52130 was produced by LLM1 and that amino acid Asp(388) was essential for CPOX function. Our study provides the basis for further investigations into the mechanism underlying lesion mimic initiation associated with LLM1.
authors.affiliation: Rice Research Institute, Sichuan Agricultural University at Wenjiang, Chengdu, Sichuan 611130, China; Key Laboratory of Major Crop Diseases, Sichuan Agricultural University at Wenjiang, Chengdu 611130, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.affiliation: Rice Research Institute, Sichuan Agricultural University at Wenjiang, Chengdu, Sichuan 611130, China; Key Laboratory of Major Crop Diseases, Sichuan Agricultural University at Wenjiang, Chengdu 611130, China.
authors.forename: Bangquan
authors.initials: B
authors.lastname: Ye
authors.affiliation: Rice Research Institute, Sichuan Agricultural University at Wenjiang, Chengdu, Sichuan 611130, China; Key Laboratory of Major Crop Diseases, Sichuan Agricultural University at Wenjiang, Chengdu 611130, China.
authors.forename: Junjie
authors.initials: J
authors.lastname: Yin
authors.affiliation: Rice Research Institute, Sichuan Agricultural University at Wenjiang, Chengdu, Sichuan 611130, China; Key Laboratory of Major Crop Diseases, Sichuan Agricultural University at Wenjiang, Chengdu 611130, China.
authors.forename: Can
authors.initials: C
authors.lastname: Yuan
authors.affiliation: Rice Research Institute, Sichuan Agricultural University at Wenjiang, Chengdu, Sichuan 611130, China; Key Laboratory of Major Crop Diseases, Sichuan Agricultural University at Wenjiang, Chengdu 611130, China.
authors.forename: Xiaogang
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Rice Research Institute, Sichuan Agricultural University at Wenjiang, Chengdu, Sichuan 611130, China; Key Laboratory of Major Crop Diseases, Sichuan Agricultural University at Wenjiang, Chengdu 611130, China.
authors.forename: Weitao
authors.initials: W
authors.lastname: Li
authors.affiliation: Rice Research Institute, Sichuan Agricultural University at Wenjiang, Chengdu, Sichuan 611130, China; Key Laboratory of Major Crop Diseases, Sichuan Agricultural University at Wenjiang, Chengdu 611130, China.
authors.forename: Min
authors.initials: M
authors.lastname: He
authors.affiliation: Rice Research Institute, Sichuan Agricultural University at Wenjiang, Chengdu, Sichuan 611130, China; Key Laboratory of Major Crop Diseases, Sichuan Agricultural University at Wenjiang, Chengdu 611130, China.
authors.forename: Jichun
authors.initials: J
authors.lastname: Wang
authors.affiliation: Rice Research Institute, Sichuan Agricultural University at Wenjiang, Chengdu, Sichuan 611130, China; Key Laboratory of Major Crop Diseases, Sichuan Agricultural University at Wenjiang, Chengdu 611130, China.
authors.forename: Weilan
authors.initials: W
authors.lastname: Chen
authors.affiliation: Rice Research Institute, Sichuan Agricultural University at Wenjiang, Chengdu, Sichuan 611130, China; Key Laboratory of Major Crop Diseases, Sichuan Agricultural University at Wenjiang, Chengdu 611130, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Qin
authors.affiliation: Rice Research Institute, Sichuan Agricultural University at Wenjiang, Chengdu, Sichuan 611130, China; Key Laboratory of Major Crop Diseases, Sichuan Agricultural University at Wenjiang, Chengdu 611130, China.
authors.forename: Bintian
authors.initials: B
authors.lastname: Ma
authors.affiliation: Rice Research Institute, Sichuan Agricultural University at Wenjiang, Chengdu, Sichuan 611130, China; Key Laboratory of Major Crop Diseases, Sichuan Agricultural University at Wenjiang, Chengdu 611130, China; Collaborative Innovation Center for Hybrid Rice in Yangtze River Basin at Sichuan, Chengdu 611130, China.
authors.forename: Yuping
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Rice Research Institute, Sichuan Agricultural University at Wenjiang, Chengdu, Sichuan 611130, China; Key Laboratory of Major Crop Diseases, Sichuan Agricultural University at Wenjiang, Chengdu 611130, China; State Key Laboratory of Hybrid Rice, Sichuan Agricultural University at Wenjiang, Chengdu 611130, China; Collaborative Innovation Center for Hybrid Rice in Yangtze River Basin at Sichuan, Chengdu 611130, China.
authors.forename: Shigui
authors.initials: S
authors.lastname: Li
authors.affiliation: Rice Research Institute, Sichuan Agricultural University at Wenjiang, Chengdu, Sichuan 611130, China; Key Laboratory of Major Crop Diseases, Sichuan Agricultural University at Wenjiang, Chengdu 611130, China; State Key Laboratory of Hybrid Rice, Sichuan Agricultural University at Wenjiang, Chengdu 611130, China; Collaborative Innovation Center for Hybrid Rice in Yangtze River Basin at Sichuan, Chengdu 611130, China. Electronic address: xwchen88@163.com.
authors.forename: Xuewei
authors.initials: X
authors.lastname: Chen
mesh_terms: D002736:Chloroplasts / Q000648:ultrastructure; D002874:Chromosome Mapping; D003304:Coproporphyrinogen Oxidase / Q000235:genetics* / Q000378:metabolism; D060467:Disease Resistance; D056426:Genetic Loci / Q000235:genetics; D008027:Light; D009154:Mutation; D012275:Oryza / Q000201:enzymology* / Q000235:genetics / Q000276:immunology / Q000528:radiation effects; D010641:Phenotype; D010935:Plant Diseases / Q000276:immunology*; D018515:Plant Leaves / Q000201:enzymology / Q000235:genetics / Q000276:immunology / Q000528:radiation effects; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D012639:Seeds / Q000201:enzymology / Q000235:genetics / Q000276:immunology / Q000528:radiation effects
chemical_list: D010940:Plant Proteins; D017382:Reactive Oxygen Species; D003304:Coproporphyrinogen Oxidase
keywords: Chloroplast; Gene mapping; Lesion mimic; Rice