The Flowering Repressor SVP Confers Drought Resistance in Arabidopsis by Regulating Abscisic Acid Catabolism

First author: Zhen Wang; Affiliations: Shanghai Center for Plant Stress Biology and Center of Excellence in Molecular Plant Sciences, Chinese Academy of Sciences (中科院上海植物逆境生物学研究中心): Shanghai China

Corresponding author: Jian-Kang Zhu (朱健康)

Terrestrial plants must cope with (应付) drought stress for survival. Under drought stress, plants accumulate the phytohormone abscisic acid (ABA) by increasing biosynthesis and decreasing catabolism (分解代谢). However, the regulatory pathway controlling ABA catabolism in response to drought is unclear. Here, we report that the flowering repressor SHORT VEGETATIVE PHASE (SVP) is induced by drought stress, associates with the promoter regions of ABA catabolism pathway genes CYP707A1/3 and AtBG1, causing repression of CYP707A1/3 and enhancement of AtBG1 expression in Arabidopsis leaves. Loss-of-function mutations in CYP707A1/3 or overexpression of AtBG1 can rescue the drought-hypersensitive phenotype of svp mutant plants via increasing cellular ABA levels. Our results suggest that SVP is a central regulator of ABA catabolism, and the regulatory pathway involving SVP, CYP707A1/3 and AtBG1 in response to water deficit plays a critical role in plant drought resistance.

陆地植物为了生存必须能够应对干旱胁迫。在干旱胁迫时，植物会通过增加脱落酸ABA的生物合成和降低ABA的分解代谢在植物体内积累ABA。然而，植物体内响应干旱条件调控ABA分解代谢的分子调控通路还不清楚。本文报道了开花抑制基因SVP受到干旱胁迫的诱导，并与ABA分解代谢通路基因CYP707A1/3和AtBG1的启动子区域相关联，能够在拟南芥叶片中抑制CYP707A1/3基因的表达，增强AtBG1基因的表达。CYP707A1/3基因功能缺失突变体或者AtBG1基因过表达突变体能够通过增加细胞内ABA的水平恢复svp突变体植株干旱超敏感的表型。本文的结果显示SVP是ABA分解代谢的关键调控子，同时响应于水分缺失的SVP、CYP707A1/3和AtBG1基因组成的调控通路在植物干旱抗性中发挥重要作用。

doi: https://doi.org/10.1016/j.molp.2018.06.009

Journal: Molecular Plant

Accepted Date: 13 July, 2018

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