A Raf-like protein kinase BHP mediates blue light-dependent stomatal opening.
A Raf-like protein kinase BHP mediates blue light-dependent stomatal opening.
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DOI：
10.1038/srep45586
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发表时间：
2017-03-30
影响因子：
4.6
通讯作者：
Kinoshita T
中科院分区：
文献类型：
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作者：
Hayashi M;Inoue SI;Ueno Y;Kinoshita T
植物表皮的气孔对蓝光有反应，通过调节CO2吸收和蒸腾作用影响光合作用和植物生长。在蓝光下，气孔保卫细胞质膜H+-ATPase通过蓝光受体光致蛋白和信号转导蛋白BLUS 1磷酸化并激活，H+-ATPase激活驱动气孔开放。然而，向光蛋白和H+-ATP酶之间的信号转导的细节仍然在很大程度上未知。本研究通过筛选蓝光依赖的H ~+-ATP酶磷酸化的特异性抑制剂，鉴定出一种Raf-like蛋白激酶，即蓝光依赖的H ~+-ATP酶磷酸化（BLUE LIGHT-DEPENDENT H ~+-ATP酶PHOSPHORILATION，BHP）。bhp突变体中的保卫细胞对蓝光的反应表现出气孔开放和H+-ATP酶磷酸化的损害。BHP在保卫细胞的胞质溶胶中大量表达，并在体外和体内与BLUS 1相互作用。基于这些结果，BHP是蓝光依赖的气孔开放的一种新的信号介质，可能是BLUS 1的下游。
Stomata in the plant epidermis open in response to blue light and affect photosynthesis and plant growth by regulating CO2 uptake and transpiration. In stomatal guard cells under blue light, plasma membrane H+-ATPase is phosphorylated and activated via blue light-receptor phototropins and a signaling mediator BLUS1, and H+-ATPase activation drives stomatal opening. However, details of the signaling between phototropins and H+-ATPase remain largely unknown. In this study, through a screening of specific inhibitors for the blue light-dependent H+-ATPase phosphorylation in guard cells, we identified a Raf-like protein kinase, BLUE LIGHT-DEPENDENT H+-ATPASE PHOSPHORYLATION (BHP). Guard cells in the bhp mutant showed impairments of stomatal opening and H+-ATPase phosphorylation in response to blue light. BHP is abundantly expressed in the cytosol of guard cells and interacts with BLUS1 both in vitro and in vivo. Based on these results, BHP is a novel signaling mediator in blue light-dependent stomatal opening, likely downstream of BLUS1.