Characterization of potential ABA receptors in Vitis vinifera
Characterization of potential ABA receptors in Vitis vinifera
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DOI：
10.1007/s00299-011-1166-z
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发表时间：
2012-02-01
影响因子：
6.2
通讯作者：
Ben-Ari, Giora
中科院分区：
文献类型：
--
作者：
Boneh, Uri;Biton, Iris;Ben-Ari, Giora
非生物胁迫耐受性的分子调控机制是基于特定胁迫相关基因的激活和调控。植物激素脱落酸（阿坝）是植物对这种胁迫反应的关键内源信使。最近发现了一种新的阿坝结合机制，它在植物细胞信号级联中起着关键作用。在不存在阿坝的情况下，2C型蛋白磷酸酶（PP 2C）相互作用并抑制激酶SnRK 2。阿坝与PYR/PYLs受体的结合使得阿坝受体与PP 2C蛋白之间能够相互作用，并消除SnRK 2失活。然后，活性SnRK 2自由激活靶向ABA依赖性基因表达的ABA响应元件结合因子。本文以葡萄为模型，研究了阿坝在果树中的感受机制。葡萄阿坝信号级联由至少7个阿坝受体和6个PP 2Cs组成。我们使用酵母双杂交系统来研究葡萄阿坝受体和它们的相互作用伙伴之间的体外物理相互作用，发现22个受体-PP 2C相互作用可以发生。此外，通过使用LacZ报告分子定量这些亲和力使我们能够表明VvPP 2C 4和VvPP 2C 9是阿坝受体的主要结合伴侣。我们还在体内测试了各种阿坝受体和PP 2Cs在外源阿坝的存在下，在不同的非生物胁迫下，如高盐浓度，寒冷和干旱的根和叶的基因表达，并发现这些基因中的许多被这样的非生物环境因子调节。我们的研究结果表明阿坝受体基因的器官特异性和压力特异性的VvPP 2Cs。我们认为，VvPP 2C 4是参与叶片和根中阿坝感知的主要PP 2C，VvRCAR 6和VvRCAR 5分别是这些器官中参与阿坝感知的主要受体。在果树阿坝信号级联的核心球员的识别，表征和操纵可能被证明是必不可少的，以提高他们的表现在未来。
Molecular control mechanisms for abiotic stress tolerance are based on the activation and regulation of specific stress-related genes. The phytohormone abscisic acid (ABA) is a key endogenous messenger in a plant's response to such stresses. A novel ABA binding mechanism which plays a key role in plant cell signaling cascades has recently been uncovered. In the absence of ABA, a type 2C protein phosphatase (PP2C) interacts and inhibits the kinase SnRK2. Binding of ABA to the PYR/PYLs receptors enables interaction between the ABA receptor and the PP2C protein, and abrogates the SnRK2 inactivation. The active SnRK2 is then free to activate the ABA-responsive element Binding Factors which target ABA-dependent gene expression. We used the grape as a model to study the ABA perception mechanism in fruit trees. The grape ABA signaling cascade consists of at least seven ABA receptors and six PP2Cs. We used a yeast two-hybrid system to examine physical interaction in vitro between the grape ABA receptors and their interacting partners, and found that twenty-two receptor-PP2C interactions can occur. Moreover, quantifying these affinities by the use of the LacZ reporter enables us to show that VvPP2C4 and VvPP2C9 are the major binding partners of the ABA receptor. We also tested in vivo the root and leaf gene expression of the various ABA receptors and PP2Cs in the presence of exogenic ABA and under different abiotic stresses such as high salt concentration, cold and drought, and found that many of these genes are regulated by such abiotic environmental factors. Our results indicate organ specificity in the ABA receptor genes and stress specificity in the VvPP2Cs. We suggest that VvPP2C4 is the major PP2C involved in ABA perception in leaves and roots, and VvRCAR6 and VvRCAR5 respectively, are the major receptors involved in ABA perception in these organs. Identification, characterization and manipulation of the central players in the ABA signaling cascades in fruit trees is likely to prove essential for improving their performance in the future.