Aquaporins facilitate hydrogen peroxide entry into guard cells to mediate ABA- and pathogen-triggered stomatal closure
Aquaporins facilitate hydrogen peroxide entry into guard cells to mediate ABA- and pathogen-triggered stomatal closure
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DOI：
10.1073/pnas.1704754114
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发表时间：
2017-08-22
影响因子：
11.1
通讯作者：
Verdoucq, Lionel
中科院分区：
文献类型：
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作者：
Rodrigues, Olivier;Reshetnyak, Ganna;Verdoucq, Lionel
气孔运动对于植物水分状况的控制和对病原体的保护至关重要。对表皮的分析表明，类似于脱落酸（阿坝），病原体相关分子模式（PAMP）flg 22需要AtPIP 2; 1水通道蛋白诱导气孔关闭。Flg 22还通过激活AtPIP 2诱导保卫细胞原生质体的渗透水透性（P-f）增加; 1.细胞内过氧化氢（H2 O2）的遗传探针Hyperer的使用表明，阿坝和flg 22都引发了H2 O2在野生型但不是pip 2; 1保卫细胞中的积累。用flg 22或阿坝预处理保卫细胞有利于外源H2 O2的内流。在体外，对类甾醇不敏感的1相关受体激酶1（BAK 1）和开放气孔1（OST 1）/Snf 1相关蛋白激酶2.6（SnRK2.6）都是flg 22诱导P-f所必需的，并且都磷酸化Ser 121上的AtPIP 2; 1。过氧化氢的积累和气孔关闭诱导flg 22恢复pip 2; 1保卫细胞的拟磷酸化形式（Ser 121 Asp），但不是由磷酸缺乏形式（Ser 121 Ala）的AtPIP 2; 1。我们提出了一种机制，即由BAK 1和/或OST 1磷酸化AtPIP 2; 1 Ser 121被flg 22激活其水和H2 O2转运活性。这项工作确立了质膜水通道蛋白在保卫细胞中的信号传导作用，并可能在其他涉及H2 O2信号传导的细胞环境中发挥作用。
Stomatal movements are crucial for the control of plant water status and protection against pathogens. Assays on epidermal peels revealed that, similar to abscisic acid (ABA), pathogen-associated molecular pattern (PAMP) flg22 requires the AtPIP2; 1 aquaporin to induce stomatal closure. Flg22 also induced an increase in osmotic water permeability (P-f) of guard cell protoplasts through activation of AtPIP2; 1. The use of HyPer, a genetic probe for intracellular hydrogen peroxide (H2O2), revealed that both ABA and flg22 triggered an accumulation of H2O2 in wild-type but not pip2; 1 guard cells. Pre-treatment of guard cells with flg22 or ABA facilitated the influx of exogenous H2O2. Brassinosteroid insensitive 1-associated receptor kinase 1 (BAK1) and open stomata 1 (OST1)/Snf1-related protein kinase 2.6 (SnRK2.6) were both necessary to flg22-induced P-f and both phosphorylated AtPIP2; 1 on Ser121 in vitro. Accumulation of H2O2 and stomatal closure as induced by flg22 was restored in pip2; 1 guard cells by a phosphomimetic form (Ser121Asp) but not by a phosphodeficient form (Ser121Ala) of AtPIP2; 1. We propose amechanismwhereby phosphorylation of AtPIP2; 1 Ser121 by BAK1 and/or OST1 is triggered in response to flg22 to activate its water and H2O2 transport activities. This work establishes a signaling role of plasmamembrane aquaporins in guard cells and potentially in other cellular context involving H2O2 signaling.