Overexpression of the protein disulfide isomerase AtCYO1 in chloroplasts slows dark-induced senescence in Arabidopsis

BMC Plant Biology

Hiroshi Shimada¹  Yasutoshi Nakahara¹  Daisuke Horikawa¹  Atsushi Sakamoto¹  Jun Tominaga¹  Ayumi Tanaka²  Wataru Sakamoto³  Tsuneaki Takami³  Kazutoshi Unno⁴  Maki Kondo⁵  Yasuhiro Kamei⁵ 

[1]Department of Mathematical and Life Sciences, Graduate School of Science, Hiroshima University

[2]Institute of Low Temperature Science, Hokkaido University

[3]Institute of Plant Science and Resources, Okayama University

[4]Laboratory of Electron Microscopy, University Hospital, Mizonokuchi, Teikyo University School of Medicine

[5]National Institute for Basic Biology

关键词: DnaJ-like zinc-finger protein;    Stay-green;    Redox;    Proteolysis;    Ectopic expression;    Arabidopsis thaliana;   

DOI  :  10.1186/s12870-018-1294-5

来源: DOAJ

【 摘 要 】

Abstract Background Chlorophyll breakdown is the most obvious sign of leaf senescence. The chlorophyll catabolism pathway and the associated proteins/genes have been identified in considerable detail by genetic approaches combined with stay-green phenotyping. Arabidopsis CYO1 (AtCYO1), a protein disulfide reductase/isomerase localized in the thylakoid membrane, is hypothesized to assemble the photosystem by interacting with cysteine residues of the subunits. Results In this study, we report that ectopic overexpression of AtCYO1 in leaves induces a stay-green phenotype during darkness, where oxidative conditions favor catabolism. In AtCYO1ox leaves, Fv/Fm and both chlorophyll a and chlorophyll b content remained high during dark-induced senescence. The thylakoid ultrastructure was preserved for a longer time in AtCYO1ox leaves than in wild type leaves. AtCYO1ox leaves maintained thylakoid chlorophyll-binding proteins associated with both PSII (D1, D2, CP43, CP47, LHCB2, and Cyt f) and PSI (PSA-A/B), as well as stromal proteins (Rubisco and ferredoxin-NADP+ reductase). AtCYO1ox did not affect senescence-inducible gene expression for chlorophyll catabolism or accumulation of chlorophyll catabolites. Conclusions Our results suggest that ectopic overexpression of AtCYO1 had a negative impact on the initiation of chlorophyll degradation and proteolysis within chloroplasts. Our findings cast new light on the redox regulation of protein disulfide bonds for the maintenance of functional chloroplasts.

【 授权许可】

Unknown