Arabidopsis VQ18 and VQ26 proteins interact with ABI5 transcription factor to negatively modulate ABA response during seed germination
Arabidopsis VQ18 and VQ26 proteins interact with ABI5 transcription factor to negatively modulate ABA response during seed germination
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拟南芥 VQ18 和 VQ26 蛋白与 ABI5 转录因子相互作用，负向调节种子萌发过程中的 ABA 反应
DOI：
10.1111/tpj.13969
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发表时间：
2018-08-01
期刊：
影响因子：
7.2
通讯作者：
Yu, Diqiu
中科院分区：
文献类型：
--
作者：
Pan, Jinjing;Wang, Houping;Yu, Diqiu
种子萌发和早期成苗是种子植物生活史中的关键发育阶段，受多种内源激素和周围环境的调节。拟南芥脱落酸不敏感5（ABI5）是脱落酸（阿坝）信号转导的一个中心转录因子，抑制这些过程。ABI5在翻译后水平被精确调控，然而，它是否与其他关键的转录调控因子相互作用仍有待研究。在这项研究中，VQ 18和VQ 26，最近确定的VQ家族的两个成员，被发现在体外和体内与ABI 5相互作用。表型分析表明，VQ18和VQ26对阿坝有反应，并在种子萌发过程中负介导阿坝信号。同时降低VQ18和VQ26的表达水平增强阿坝信号抑制种子萌发，而过表达这两个VQ基因导致发芽的种子ABA敏感性降低。因此，几种ABI5靶标的表达水平受到VQ18和VQ26的调节。VQ18和VQ26同时被抑制的植物中增加的阿坝信号传导需要ABI5。另外，VQ18和VQ26作为ABI5转录因子的负相互作用物。我们的研究揭示了VQ蛋白以前未识别的调节作用，它们与ABI5起拮抗作用，以维持适当的阿坝信号水平，从而微调种子萌发和早期幼苗建立。
Seed germination and early seedling establishment, critical developmental stages in the life cycle of seed plants, are modulated by diverse endogenous hormones and the surrounding environment. Arabidopsis ABSCISIC ACID-INSENSITIVE5 (ABI5) is a central transcription factor of abscisic acid (ABA) signaling that represses those processes. ABI5 is precisely modulated at post-translational level; however, whether it interacts with other crucial transcriptional regulators remains to be investigated. In this study, VQ18 and VQ26, two members of the recently-identified VQ family, were found to interact with ABI5 in vitro and in vivo. Phenotypic analysis showed that VQ18 and VQ26 are responsive to ABA and negatively mediate ABA signaling redundantly during seed germination. Simultaneously decreasing VQ18 and VQ26 expression levels enhanced ABA signaling to suppress seed germination, whereas overexpressing these two VQ genes resulted in the germinated seeds being less ABA-sensitive. Consistently, the expression levels of several ABI5 targets were modulated by VQ18 and VQ26. The increased ABA signaling of plants in which VQ18 and VQ26 were simultaneously suppressed required ABI5. Additionally, VQ18 and VQ26 acted as negative interactors of the ABI5 transcription factor. Our study reveals a previously unidentified regulatory role of VQ proteins, which act antagonistically with ABI5 to maintain the appropriate ABA signaling level to fine-tune seed germination and early seedling establishment.