title: AtACDO1, an ABC1-like kinase gene, is involved in chlorophyll degradation and the response to photooxidative stress in Arabidopsis.
abstract: ABC1 (activity of bc1 complex) is a newly discovered atypical kinase in plants. Here, it is reported that an ABC1 protein kinase-encoded gene, AtACDO1 (ABC1-like kinase related to chlorophyll degradation and oxidative stress), located in chloroplasts, was up-regulated by methyl viologen (MV) treatment. AtACDO1 RNAi (RNA interference) plants showed developmental defects, including yellow-green leaves and reduced contents of carotenoids and chlorophyll; the chlorophyll reduction was associated with a change in the numbers of chlorophyll-binding proteins of the photosynthetic complexes. Chlorophyllide (Chlide) a the first product of chlorophyll degradation, and pheophorbide a, a subsequent intermediate of Chlide a degradation, were increased in AtACDO1 RNAi plants. The AtACDO1 RNAi plants were more sensitive to high light and MV than wild-type plants. The AtACDO1 RNAi plants had lower transcript levels of the oxidative stress response genes FSD1, CSD1, CAT1, and UTG71C1 after MV treatment compared with wild-type or 35S::AtACDO1 plants. Taken together, the results suggest that the chloroplast AtACDO1 protein plays important roles in mediating chlorophyll degradation and maintaining the number of chlorophyll-binding photosynthetic thylakoid membranes, as well as in the photooxidative stress response.
authors.affiliation: Guangdong Key Laboratory of Biotechnology for Plant Development, College of Life Science, South China Normal University, Guangzhou, China.
authors.forename: Songguang
authors.initials: S
authors.lastname: Yang
authors.forename: Xueqin
authors.initials: X
authors.lastname: Zeng
authors.forename: Tao
authors.initials: T
authors.lastname: Li
authors.forename: Ming
authors.initials: M
authors.lastname: Liu
authors.forename: Shengchun
authors.initials: S
authors.lastname: Zhang
authors.forename: Sujuan
authors.initials: S
authors.lastname: Gao
authors.forename: Yaqin
authors.initials: Y
authors.lastname: Wang
authors.forename: Changliang
authors.initials: C
authors.lastname: Peng
authors.forename: Ling
authors.initials: L
authors.lastname: Li
authors.forename: Chengwei
authors.initials: C
authors.lastname: Yang
mesh_terms: D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects*; D002734:Chlorophyll / Q000378:metabolism*; D002735:Chlorophyllides / Q000378:metabolism; D060365:Chloroplast Proteins / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D008027:Light; D018384:Oxidative Stress / Q000528:radiation effects*; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism*
chemical_list: D002735:Chlorophyllides; D060365:Chloroplast Proteins; D002734:Chlorophyll; D011494:Protein Kinases