ABA Regulates Subcellular Redistribution of OsABI-LIKE2, a Negative Regulator in ABA Signaling, to Control Root Architecture and Drought Resistance in Oryza sativa
ABA Regulates Subcellular Redistribution of OsABI-LIKE2, a Negative Regulator in ABA Signaling, to Control Root Architecture and Drought Resistance in Oryza sativa
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DOI：
10.1093/pcp/pcv154
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发表时间：
2015-12-01
影响因子：
4.9
通讯作者：
Wang, Xuelu
中科院分区：
文献类型：
--
作者：
Li, Chengxiang;Shen, Hongyun;Wang, Xuelu
植物激素阿坝是植物体内重要的逆境信号。虽然阿坝受体的鉴定导致了对拟南芥阿坝信号通路的理解取得了重大进展，但关于单子叶植物（如水稻）中的阿坝信号通路仍有许多未解之谜。在这里，我们报告，水稻直系同源的AtABI 1和AtABI 2，命名为OsABI-LIKE 2（OsABIL 2），在水稻阿坝信号中起着负作用。OsABIL 2的过量表达不仅导致阿坝不敏感，而且显著改变了植物的气孔密度和根构型等发育表型，这可能是导致植物对干旱胁迫敏感的原因。OsABIL 2与OsPYL 1、SAPK 8和SAPK 10在体内外均能相互作用，OsPYL 1与ABA结合后可抑制OsABIL 2的磷酸酶活性。然而，与许多其他仅核定位的进化枝A型2C蛋白磷酸酶（PP 2Cs）不同，OsABIL 2定位于细胞核和细胞质中。此外，OsABIL 2与OsPYL 1主要在胞质中相互作用并共定位，阿坝处理可调节OsABIL 2在核-胞质中的分布，这表明阿坝信号的激活机制与OsPYL 1不同。综上所述，本研究为水稻阿坝信号转导提供了重要的见解，并表明OsABIL 2在调控根发育中的重要作用。
The phytohormone ABA is a key stress signal in plants. Although the identification of ABA receptors led to significant progress in understanding the Arabidopsis ABA signaling pathway, there are still many unsolved mysteries regarding ABA signaling in monocots, such as rice. Here, we report that a rice ortholog of AtABI1 and AtABI2, named OsABI-LIKE2 (OsABIL2), plays a negative role in rice ABA signaling. Overexpression of OsABIL2 not only led to ABA insensitivity, but also significantly altered plant developmental phenotypes, including stomatal density and root architecture, which probably caused the hypersensitivity to drought stress. OsABIL2 interacts with OsPYL1, SAPK8 and SAPK10 both in vitro and in vivo, and the phosphatase activity of OsABIL2 was repressed by ABA-bound OsPYL1. However, unlike many other solely nuclear-localized clade A type 2C protein phosphatases (PP2Cs), OsABIL2 is localized in both the nucleus and cytosol. Furthermore, OsABIL2 interacts with and co-localized with OsPYL1 mainly in the cytosol, and ABA treatment regulates the nucleus-cytosol distribution of OsABIL2, suggesting a different mechanism for the activation of ABA signaling. Taken together, this study provides significant insights into rice ABA signaling and indicates the important role of OsABIL2 in regulating root development.