Counteraction of ABA-Mediated Inhibition of Seed Germination and Seedling Establishment by ABA Signaling Terminator in Arabidopsis.
Counteraction of ABA-Mediated Inhibition of Seed Germination and Seedling Establishment by ABA Signaling Terminator in Arabidopsis.
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DOI：
10.1016/j.molp.2020.06.011
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发表时间：
2020-06
期刊：
影响因子：
27.5
通讯作者：
Zhijuan Wang;Ziyin Ren;Chunhong Cheng;Tao Wang;Hongtao Ji;Yang Zhao;Z. Deng;Liya Zhi;Jingjing Lu-J
中科院分区：
文献类型：
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作者：
Zhijuan Wang;Ziyin Ren;Chunhong Cheng;Tao Wang;Hongtao Ji;Yang Zhao;Z. Deng;Liya Zhi;Jingjing Lu-J
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.ABTis induced by ABA in a PYR1/PYL/RCAR-PP2C-dependent manner. Overexpression ofABTpromotes seed germination and seedling greening in the presence of ABA, whereas knockout ofABThas 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 inArabidopsis.
