Mutation of chloroplast CHLM contributes to down-regulation of multiple stress response genes in Arabidopsis

编号 040023804

推送时间 20200511

研究领域 森林培育 

年份 2020 

类型 期刊 

语种 英语

标题 Mutation of chloroplast CHLM contributes to down-regulation of multiple stress response genes in Arabidopsis

来源期刊 Plant Growth Regulation

期 第238期

发表时间 20200403

关键词 Arabidopsis thaliana;  CHLM;  reactive oxygen species;  salt stress;  nuclear gene expression; 

摘要 Mg-protoporphyrin IX methyltransferase (CHLM) plays a crucial role in chlorophyll biosynthesis and converts Mg-protoporphyrin IX to Mg-protoporphyrin IX monomethyl ester. Previous research has indicated that down-expression of CHLM causes a pale green phenotype and Mg-protoporphyrin IX accumulation in Arabidopsis thaliana plants. Here, we report that a novel missense mutation (G to A transition) in the CHLM gene, results in the Gly59 → Glu amino acid substitution in the corresponding protein of Arabidopsis chlm-4 mutant plants. In silico modelling studies suggested that this substitution may disrupt membrane association of CHLM. Functional studies showed that the mutant form of CHLM leads to the excessive accumulation of superoxide anion radicals (O2?), although elimination of O2? could alleviate the yellow phenotype observed in chlm-4. In addition, qRT-PCR and western blotting analysis demonstrated that the expression of O2? scavengers, FSD1 and CSD2, were repressed in chlm-4 plants. The accumulation of photosystem II proteins was also decreased due to the CHLM mutation. Furthermore, we found that chlm-4 plants exhibited hypersensitive salt-stress during seed germination and down-expression of the salt stress-responsive CBFs-family genes. These results suggest CHLM positively regulates the expression of multiple photosynthetic-related and stress-responsive nuclear genes.

服务人员 孙小满

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