The Calcium Sensor CBL2 and Its Interacting Kinase CIPK6 Are Involved in Plant Sugar Homeostasis via Interacting with Tonoplast Sugar Transporter TST21
The Calcium Sensor CBL2 and Its Interacting Kinase CIPK6 Are Involved in Plant Sugar Homeostasis via Interacting with Tonoplast Sugar Transporter TST21
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DOI：
10.1104/pp.19.01368
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发表时间：
2020-05-01
期刊：
影响因子：
7.4
通讯作者：
Zhang, Xianlong
中科院分区：
文献类型：
--
作者：
Deng, Jinwu;Yang, Xiyan;Zhang, Xianlong
钙调磷酸酶B样蛋白相互作用蛋白激酶6（CIPK 6）被钙调磷酸酶B样蛋白2（CBL 2）募集到液泡膜，并与液泡膜定位的糖转运蛋白TST 2相互作用以促进糖积累，特别是葡萄糖，钙调磷酸酶B样蛋白（CBL）和CBL相互作用蛋白激酶（CIPK）-已广泛报道介导的钙信号传导在植物发育和各种胁迫响应中起作用，特别是在离子稳态中。糖是最重要的初级代谢产物，因此糖的稳态需要精确的调节。在这里，我们描述了CBL 2-CIPK 6-液泡膜定位糖转运蛋白2（TST 2）的分子模块在棉花（陆地棉），调节植物糖稳态，特别是葡萄糖稳态。GhCIPK 6被GhCBL 2募集到液泡膜中，并与液泡膜定位的糖转运蛋白GhTST 2相互作用。GhCBL 2、GhCIPK 6或GhTST 2的过表达足以促进转基因棉花中的糖积累，而RNAi介导的GhCIPK 6表达敲除或CRISPR-Cas9介导的GhTST 2敲除导致葡萄糖含量显著降低。此外，GhCIPK 6过表达棉花中GhCBL 2或GhTST 2的突变恢复了与野生型植物相当的糖含量。GhCIPK 6在拟南芥中的异源表达也促进了Glc的积累，而GhCIPK 6过表达的拟南芥中AtTST 1/2的突变同样恢复了野生型糖含量，从而表明CBL 2-CIPK 6-TST 2介导的糖稳态在不同植物物种中的保守性。我们对植物糖稳态背后的分子参与者的表征可能被利用来提高植物中的糖含量和非生物胁迫抗性。
Calcineurin B-like protein interacting protein kinase 6 (CIPK6) is recruited to the tonoplast by Calcineurin B-like protein 2 (CBL2) and interacts with the tonoplast-localized sugar transporter TST2 to promote sugar accumulation, in particular glucose, in cotton.Calcineurin B-like protein (CBL) and CBL-interacting protein kinase (CIPK)-mediated calcium signaling has been widely reported to function in plant development and various stress responses, particularly in ion homeostasis. Sugars are the most important primary metabolites, and thus sugar homeostasis requires precise regulation. Here, we describe a CBL2-CIPK6-Tonoplast-Localized Sugar Transporter2 (TST2) molecular module in cotton (Gossypium hirsutum) that regulates plant sugar homeostasis, in particular Glc homeostasis. GhCIPK6 is recruited to the tonoplast by GhCBL2 and interacts with the tonoplast-localized sugar transporter GhTST2. Overexpression of either GhCBL2, GhCIPK6, or GhTST2 was sufficient to promote sugar accumulation in transgenic cotton, whereas RNAi-mediated knockdown of GhCIPK6 expression or CRISPR-Cas9-mediated knockout of GhTST2 resulted in significantly decreased Glc content. Moreover, mutation of GhCBL2 or GhTST2 in GhCIPK6-overexpressing cotton reinstated sugar contents comparable to wild-type plants. Heterologous expression of GhCIPK6 in Arabidopsis (Arabidopsis thaliana) also promoted Glc accumulation, whereas mutation of AtTST1/2 in GhCIPK6-overexpressing Arabidopsis similarly reinstated wild-type sugar contents, thus indicating conservation of CBL2-CIPK6-TST2-mediated sugar homeostasis among different plant species. Our characterization of the molecular players behind plant sugar homeostasis may be exploited to improve sugar contents and abiotic stress resistance in plants.