title: [Molecular mechanism for dynamic regulation of endogenous ABA signal level].
abstract: The process from stress signal perception and the trigger of ABA biosynthesis to dynamic regulation of ABA level is an important stress signaling pathway in cells. Compared to the downstream events in ABA signal transduction, the researches in this field are relatively lagged. Expression of synthase genes, such as ZEP in roots and rate-limiting enzyme genes NCED, AtRGS1 and ABA2, can be activated in response to stresses. However, the expression of genes encoding degradative enzymes, including 7'-, 8'-, 9'-hydroxylase and glucosyltransferase, negatively regulates ABA accumulation. Meanwhile, the expressions of the synthases, such as ZEP and NCED3, are induced by increasing endogenous ABA contents. Additionally, the analyses of gene expression and source-sink dynamics indicates that sustained supply from root-sourced ABA is required for the maintenance of leaf ABA dynamic pool. It is notable that miRNAs should be involved in ABA signal origin and ABA level dynamic adjustment. Further dynamic analysis of ABA metabolism revealed that endogenous ABA signal levels are synergistically controlled by the expressions of synthases and degradative enzymes.
authors.affiliation: Department of Biological Sciences and Biotechnology, Zhangzhou Normal University, China. kaifa-wei@163.com
authors.forename: Kai-Fa
authors.initials: KF
authors.lastname: Wei
authors.forename: Juan
authors.initials: J
authors.lastname: Chen
authors.forename: Yan-Feng
authors.initials: YF
authors.lastname: Chen
authors.forename: Ling-Juan
authors.initials: LJ
authors.lastname: Wu
authors.forename: Wen-Suo
authors.initials: WS
authors.lastname: Jia
mesh_terms: D000040:Abscisic Acid / Q000096:biosynthesis / Q000378:metabolism*; D025461:Feedback, Physiological; D018506:Gene Expression Regulation, Plant; D035683:MicroRNAs / Q000235:genetics; D010944:Plants / Q000201:enzymology / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics
chemical_list: D035683:MicroRNAs; D000040:Abscisic Acid