Arabidopsis RAV1 transcription factor, phosphorylated by SnRK2 kinases, regulates the expression of ABI3, ABI4, and ABI5 during seed germination and early seedling development
Arabidopsis RAV1 transcription factor, phosphorylated by SnRK2 kinases, regulates the expression of ABI3, ABI4, and ABI5 during seed germination and early seedling development
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拟南芥 RAV1 转录因子被 SnRK2 激酶磷酸化，在种子萌发和早期幼苗发育过程中调节 ABI3、ABI4 和 ABI5 的表达
DOI：
10.1111/tpj.12670
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发表时间：
2014-11-01
期刊：
影响因子：
7.2
通讯作者：
Chen, Yi-Fang
中科院分区：
文献类型：
--
作者：
Feng, Cui-Zhu;Chen, Yun;Chen, Yi-Fang
植物激素脱落酸（阿坝）调节植物生长发育过程中的许多过程。本研究探讨了拟南芥RAV（Related to ABI 3/VP 1）转录因子RAV 1参与阿坝信号转导的分子机制。RAV 1低表达株系在种子萌发和幼苗早期发育过程中对阿坝比野生型植株更敏感，而RAV 1过表达株系表现出强烈的ABA不敏感表型。RAV 1的过表达抑制ABI 3、ABI 4和ABI 5的表达，并且RAV 1在体外和体内与ABI 3、ABI 4和ABI 5启动子结合，表明RAV 1直接下调ABI 3、ABI 4和ABI 5的表达。在RAV 1-U abi 5植物中ABI 5功能的中断消除了RAV 1-U植物的ABA过敏表型，表明ABI 5对RAV 1具有上位性。RAV 1在细胞核中与SNF 1相关蛋白激酶SnRK2.2、SnRK2.3和SnRK2.6相互作用。体外激酶试验表明，SnRK2.2、SnRK2.3和SnRK2.6磷酸化RAV 1。瞬时表达分析表明，SnRK2.2，SnRK2.3和SnRK2.6减少RAV 1依赖的ABI 5的抑制，RAV 1过表达系的ABA不敏感表型被RAV 1 OE 3植物中SnRK2.3的过表达所损害。总之，这些结果表明，拟南芥RAV 1转录因子通过调节ABI 3、ABI 4和ABI 5的表达在阿坝信号传导中发挥重要作用，并且其活性受到SnRK 2的负面影响。
The phytohormone abscisic acid (ABA) modulates a number of processes during plant growth and development. In this study, the molecular mechanism of Arabidopsis RAV (Related to ABI3/VP1) transcription factor RAV1 involving ABA signaling was investigated. RAV1-underexpressing lines were more sensitive to ABA than wild-type plants during seed germination and early seedling development, whereas RAV1-overexpressing lines showed strong ABA-insensitive phenotypes. Overexpression of RAV1 repressed ABI3, ABI4, and ABI5 expression, and RAV1 bound to the ABI3, ABI4, and ABI5 promoters in vitro and in vivo, indicating that RAV1 directly down-regulates the expression of ABI3, ABI4, and ABI5. The interruption of ABI5 function in RAV1-U abi5 plants abolished the ABA-hypersensitive phenotype of RAV1-U plants, demonstrating that ABI5 is epistatic to RAV1. RAV1 interacted with SNF1-RELATED PROTEIN KINASE SnRK2.2, SnRK2.3 and SnRK2.6 in the nucleus. In vitro kinase assays showed that SnRK2.2, SnRK2.3 and SnRK2.6 phosphorylated RAV1. Transient expression assays revealed that SnRK2.2, SnRK2.3 and SnRK2.6 reduced the RAV1-dependent repression of ABI5, and the ABA-insensitive phenotype of the RAV1-overexpressing line was impaired by overexpression of SnRK2.3 in the RAV1 OE3 plants. Together, these results demonstrated that the Arabidopsis RAV1 transcription factor plays an important role in ABA signaling by modulating the expression of ABI3, ABI4, and ABI5, and that its activity is negatively affected by SnRK2s.