title: Negative feedback regulation of ABA biosynthesis in peanut (Arachis hypogaea): a transcription factor complex inhibits AhNCED1 expression during water stress.
abstract: Abscisic acid (ABA), a key plant stress-signaling hormone, is produced in response to drought and counteracts the effects of this stress. The accumulation of ABA is controlled by the enzyme 9-cis-epoxycarotenoid dioxygenase (NCED). In Arabidopsis, NCED3 is regulated by a positive feedback mechanism by ABA. In this study in peanut (Arachis hypogaea), we demonstrate that ABA biosynthesis is also controlled by negative feedback regulation, mediated by the inhibitory effect on AhNCED1 transcription of a protein complex between transcription factors AhNAC2 and AhAREB1. AhNCED1 was significantly down-regulated after PEG treatment for 10 h, at which time ABA content reached a peak. A ChIP-qPCR assay confirmed AhAREB1 and AhNAC2 binding to the AhNCED1 promoter in response to ABA. Moreover, the interaction between AhAREB1 and AhNAC2, and a transient expression assay showed that the protein complex could negatively regulate the expression of AhNCED1. The results also demonstrated that AhAREB1 was the key factor in AhNCED1 feedback regulation, while AhNAC2 played a subsidiary role. ABA reduced the rate of AhAREB1 degradation and enhanced both the synthesis and degradation rate of the AhNAC2 protein. In summary, the AhAREB1/AhNAC2 protein complex functions as a negative feedback regulator of drought-induced ABA biosynthesis in peanut.
authors.affiliation: Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, China.
authors.forename: Shuai
authors.initials: S
authors.lastname: Liu
authors.affiliation: Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, China.
authors.forename: Meijuan
authors.initials: M
authors.lastname: Li
authors.affiliation: Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, China.
authors.forename: Liangchen
authors.initials: L
authors.lastname: Su
authors.affiliation: Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, China.
authors.forename: Kui
authors.initials: K
authors.lastname: Ge
authors.affiliation: Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, China.
authors.forename: Limei
authors.initials: L
authors.lastname: Li
authors.affiliation: Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, China.
authors.forename: Xiaoyun
authors.initials: X
authors.lastname: Li
authors.affiliation: Molecular Analysis and Genetic Improvement Center, South China Botanical Garden, Chinese Academy of Science, Guangzhou 510650, China.
authors.forename: Xu
authors.initials: X
authors.lastname: Liu
authors.affiliation: Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Li
mesh_terms: D000040:Abscisic Acid / Q000096:biosynthesis* / Q000494:pharmacology; D017360:Arabidopsis / Q000235:genetics; D010367:Arachis / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D050976:Basic-Leucine Zipper Transcription Factors / Q000235:genetics / Q000378:metabolism*; D003681:Dehydration; D055864:Droughts; D025461:Feedback, Physiological; D018506:Gene Expression Regulation, Plant; D018515:Plant Leaves / Q000502:physiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic; D025941:Protein Interaction Mapping
chemical_list: D050976:Basic-Leucine Zipper Transcription Factors; D010940:Plant Proteins; D000040:Abscisic Acid