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HEREDITAS ›› 2012, Vol. 34 ›› Issue (3): 296-306.doi: 10.3724/SP.J.1005.2012.00296

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Molecular mechanism for dynamic regulation of endogenous ABA signal level

WEI Kai-Fa1, CHEN Juan1, CHEN Yan-Feng1, WU Ling-Juan1, JIA Wen-Suo2   

  1. 1. Department of Biological Sciences and Biotechnology, Zhangzhou Normal University, Zhangzhou 363000, China 2. College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China
  • Received:2011-11-05 Revised:2011-12-26 Online:2012-03-20 Published:2012-03-25
  • Contact: WEI Kai-Fa E-mail:kaifa-wei@163.com

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 en-dogenous 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 re-vealed that endogenous ABA signal levels are synergistically controlled by the expressions of synthases and degradative enzymes.

Key words: degradative regulation, feedback regulation, transportation regulation, miRNA pathway, synergistic control, ABA signal levels, biosynthetic regulation