title: The role of ANAC072 in the regulation of chlorophyll degradation during age- and dark-induced leaf senescence.
abstract: ANAC072 positively regulates both age- and dark-induced leaf senescence through activating the transcription of NYE1. Leaf senescence is integral to plant development, which is age-dependent and strictly regulated by internal and environmental signals. Although a number of senescence-related mutants and senescence-associated genes (SAGs) have been identified and characterized in the past decades, the general regulatory network of leaf senescence is still far from being elucidated. Here, we report the role of ANAC072, an SAG identified through bioinformatics analysis, in the regulation of chlorophyll degradation during natural and dark-induced leaf senescence. The expression of ANAC072 was increased with advancing leaf senescence in Arabidopsis. Leaf degreening was significantly delayed under normal or dark-induced conditions in anac072-1, a knockout mutant of ANAC072, with a higher chlorophyll level detected. In contrast, an overexpression mutant, anac072-2, with ANAC072 transcription markedly upregulated, showed an early leaf-yellowing phenotype. Consistently, senescent leaves of the loss-of-function mutant anac072-1 exhibited delays in the decrease of photosynthesis efficiency of photosystem II (F v/F m ratio) and the increase of plasma membrane ion leakage rate as compared with corresponding leaves of wild-type Col-0 plants, whereas the overexpression mutant anac072-2 showed opposite changes. Our data suggest that ANAC072 plays a positive role during natural and dark-induced leaf senescence. In addition, the transcript level of NYE1, a key regulatory gene in chlorophyll degradation, relied on the function of ANAC072. Combining these analyses with electrophoretic mobility shift assay and chromatin immunoprecipitation, we demonstrated that ANAC072 directly bound to the NYE1 promoter in vitro and in vivo, so ANAC072 may promote chlorophyll degradation by directly upregulating the expression of NYE1.
authors.affiliation: State Key Laboratory of Genetic Engineering, Institute of Plant Biology, School of Life Sciences, Fudan University, 220 Handan Road, Shanghai, 200433, China.
authors.forename: Shou
authors.initials: S
authors.lastname: Li
authors.affiliation: State Key Laboratory of Genetic Engineering, Institute of Plant Biology, School of Life Sciences, Fudan University, 220 Handan Road, Shanghai, 200433, China.
authors.forename: Jiong
authors.initials: J
authors.lastname: Gao
authors.affiliation: State Key Laboratory of Genetic Engineering, Institute of Plant Biology, School of Life Sciences, Fudan University, 220 Handan Road, Shanghai, 200433, China.
authors.forename: Lingya
authors.initials: L
authors.lastname: Yao
authors.affiliation: State Key Laboratory of Genetic Engineering, Institute of Plant Biology, School of Life Sciences, Fudan University, 220 Handan Road, Shanghai, 200433, China.
authors.forename: Guodong
authors.initials: G
authors.lastname: Ren
authors.affiliation: State Key Laboratory of Genetic Engineering, Institute of Plant Biology, School of Life Sciences, Fudan University, 220 Handan Road, Shanghai, 200433, China.
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Genetic Engineering, Institute of Plant Biology, School of Life Sciences, Fudan University, 220 Handan Road, Shanghai, 200433, China.
authors.forename: Shan
authors.initials: S
authors.lastname: Gao
authors.affiliation: State Key Laboratory of Genetic Engineering, Institute of Plant Biology, School of Life Sciences, Fudan University, 220 Handan Road, Shanghai, 200433, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Qiu
authors.affiliation: State Key Laboratory of Genetic Engineering, Institute of Plant Biology, School of Life Sciences, Fudan University, 220 Handan Road, Shanghai, 200433, China. zhouxin@fudan.edu.cn.
authors.forename: Xin
authors.initials: X
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Genetic Engineering, Institute of Plant Biology, School of Life Sciences, Fudan University, 220 Handan Road, Shanghai, 200433, China. bkkuai@fudan.edu.cn.
authors.forename: Benke
authors.initials: B
authors.lastname: Kuai
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D002734:Chlorophyll / Q000378:metabolism*; D003624:Darkness; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D018515:Plant Leaves / Q000254:growth & development* / Q000378:metabolism*; D013997:Time Factors; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D015854:Up-Regulation / Q000235:genetics
chemical_list: C493661:ANAC072 protein, Arabidopsis; D029681:Arabidopsis Proteins; D014157:Transcription Factors; D002734:Chlorophyll
keywords: ANAC072; Chlorophyll degradation; Leaf senescence; NYE1