THI1, a Thiamine Thiazole Synthase, Interacts with Ca2+-Dependent Protein Kinase CPK33 and Modulates the S-Type Anion Channels and Stomatal Closure in Arabidopsis
THI1, a Thiamine Thiazole Synthase, Interacts with Ca2+-Dependent Protein Kinase CPK33 and Modulates the S-Type Anion Channels and Stomatal Closure in Arabidopsis
复制标题
THI1 是一种硫胺噻唑合酶，与 Ca2 依赖性蛋白激酶 CPK33 相互作用并调节拟南芥中的 S 型阴离子通道和气孔关闭
DOI：
10.1104/pp.15.01649
复制
发表时间：
2016-02-01
期刊：
影响因子：
7.4
通讯作者：
Zhang, Wei
中科院分区：
文献类型：
--
作者：
Li, Chun-Long;Wang, Mei;Zhang, Wei
硫胺素是植物生长和发育所必需的。在这里，参与硫胺素噻唑合酶，THI1，已被证明在保卫细胞脱落酸（阿坝）信号和干旱反应在拟南芥（拟南芥）。THI1过表达被证明是更敏感的阿坝比野生型方面的激活保卫细胞慢型阴离子通道和气孔关闭，这有效地降低了水分从植物的损失率，从而提高其耐旱性的水平。酵母双杂交策略被用来筛选的cDNA文库从表皮条的THI1调节因子，并确定CPK33，钙依赖性蛋白激酶，作为相互作用与THI1在质膜界定的方式。功能丧失型cpk33突变体对阿坝激活慢型阴离子通道和ABA诱导的气孔关闭表现出高度敏感性，而CPK33过表达株系表现出相反的表型。CPK33激酶活性是ABA诱导气孔关闭所必需的。与它们在气孔关闭上的相反调节作用一致，THI1在体外抑制CPK33激酶活性。总之，我们的数据揭示了一种新的调节作用，硫胺噻唑合酶激酶活性在保卫细胞信号。
Thiamine is required for both plant growth and development. Here, the involvement of a thiamine thiazole synthase, THI1, has been demonstrated in both guard cell abscisic acid (ABA) signaling and the drought response in Arabidopsis (Arabidopsis thaliana). THI1 overexpressors proved to be more sensitive to ABA than the wild type with respect to both the activation of guard cell slow type anion channels and stomatal closure; this effectively reduced the rate of water loss from the plant and thereby enhanced its level of drought tolerance. A yeast two-hybrid strategy was used to screen a cDNA library from epidermal strips of leaves for THI1 regulatory factors, and identified CPK33, a Ca2+-dependent protein kinase, as interactor with THI1 in a plasma membrane-delimited manner. Loss-of-function cpk33 mutants were hypersensitive to ABA activation of slow type anion channels and ABA-induced stomatal closure, while the CPK33 overexpression lines showed opposite phenotypes. CPK33 kinase activity was essential for ABA-induced stomatal closure. Consistent with their contrasting regulatory role over stomatal closure, THI1 suppressed CPK33 kinase activity in vitro. Together, our data reveal a novel regulatory role of thiamine thiazole synthase to kinase activity in guard cell signaling.