Counteraction of ABA-Mediated Inhibition of Seed Germination and Seedling Establishment by ABA Signaling Terminator in Arabidopsis  

作　　者：Zhijuan Wang Ziyin Ren Chunhong Cheng Tao Wang Hongtao Ji Yang Zhao Zhiping Deng Liya Zhi Jingjing Lu Xinying Wu Shimin Xu Mengmeng Cao Hongtao Zhao Liu Liu Jiankang Zhu Xia Li 

机构地区：[1]National Key Laboratory of Crop Genetic Improvement,College of Plant Science and Technology,Huazhong Agricultural University,Wuhan,Hubei 430070,P.R.China [2]Center of Agricultural Resources Research,Institute of Genetics and Developmental Biology,Chinese Academy of Sciences,Shijiazhuang,Hebei 050021,P.R.China [3]University of Chinese Academy of Sciences,Beijing 100049,P.R.China [4]Shanghai Center for Plant Stress Biology,Chinese Academy of Sciences,Shanghai Institutes for Biological Sciences,Shanghai 200032,P.R.China [5]Department of Horticulture and Landscape Architecture,Purdue University,West Lafayette,IN 47907,USA [6]State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products,Institute of Virology and Biotechnology,Zhejiang Academy of Agricultural Sciences,Hangzhou,Zhejiang 3210021,P.R.China [7]College of Life Science and Technology,Yangtze Normal University,Chongqing,P.R.China [8]Key Laboratory of Mental Health,Institute of Psychology,Chinese Academy of Sciences,Beijing,P.R.China [9]College of Life Sciences in Hebei Normal University,Shijiazhuang,Hebei 050024,P.R.China

出　　处：《Molecular Plant》2020年第9期1284-1297,共14页分子植物（英文版）

基　　金：supported by the National Key Research and Development Program of China(2016YFA0500503);the Fundamental Research Funds for the Central Universities(2662018PY075);the National Natural Science Foundation of China(31730066,91540112);the Huazhong Agricultural University's Scientific and Technological Self-innovation Foundation(2015RC014).

摘　　要：Seed germination and seedling establishment are important for the reproductive success of plants,but seeds and seedlings typically encounter constantly changing environmental conditions.By inhibiting seed germination and post-germinative growth through the PYR1/PYL/RCAR ABA receptors and PP2C co-receptors,the phytohormone abscisic acid(ABA)prevents premature germination and seedling growth under unfavorable conditions.However,little is known about how the ABA-mediated inhibition of seed germination and seedling establishment is thwarted.Here,we report that ABA Signaling Terminator(ABT),a WD40 protein,efficiently switches off ABA signaling and is critical for seed germination and seedling establishment.ABT is induced by ABA in a PYR1/PYL/RCAR-PP2C-dependent manner.Overexpression of ABT promotes seed germination and seedling greening in the presence of ABA,whereas knockout of ABT has the opposite effect.We found that ABT interacts with the PYR1/PYL/RCAR and PP2C proteins,interferes with the interaction between PYR1/PYL4 and ABI1/ABI2,and hampers the inhibition of ABI1/ABI2 by ABA-bound PYR1/PYL4,thereby terminating ABA signaling.Taken together,our results reveal a core mechanism of ABA signaling termination that is critical for seed germination and seedling establishment in Arabidopsis.

关 键 词：ABA ABT ABA signaling PYR1/PYL7RCAR-ABA-PP2Cs complex seed germination post-germinative development 

分 类 号：Q94[生物学—植物学]