Reactive oxygen species (ROS), produced by respiratory burst oxidase homologs (RBOHs) at the apoplast, play a key role in local and systemic cell-to-cell signaling, required for plant acclimation to stress. Here we reveal that the Arabidopsis thaliana leucine-rich-repeat receptor-like kinase H2O2-INDUCED CA2+ INCREASES 1 (HPCA1) acts as a central ROS receptor required for the propagation of cell-to-cell ROS signals, systemic signaling in response to different biotic and abiotic stresses, stress responses at the local tissue, and plant acclimation to stress, following a local treatment of high light stress. We further report that HPCA1 is required for systemic calcium signals, but not systemic membrane depolarization responses, and identify the calcium-permeable channel MECHANOSENSITIVE ION CHANNEL LIKE 3, CALCINEURIN B-LIKE CALCIUM SENSOR 4 (CBL4), CBL4-INTERACTING PROTEIN KINASE 26, and Sucrose-non-fermenting-1-related Protein Kinase 2.6/OPEN STOMATA 1 (OST1) as required for the propagation of cell-to-cell ROS signals. In addition, we identify serine residues S343 and S347 of RBOHD (the putative targets of OST1) as playing a key role in cell-to-cell ROS signaling in response to a local application of high light stress. Our findings reveal that HPCA1 plays a key role in mediating and coordinating systemic cell-to-cell ROS and calcium signals required for plant acclimation to stress.

中文翻译：

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HPCA1 是全身活性氧和钙细胞间信号传导以及植物适应胁迫所必需的

活性氧 (ROS) 由质外体中的呼吸爆发氧化酶同系物 (RBOH) 产生，在植物适应应激所需的局部和全身细胞间信号传导中发挥着关键作用。在这里，我们揭示了拟南芥富含亮氨酸重复受体样激酶 H2O2 诱导的 CA2+ 增加 1 (HPCA1) 作为细胞间 ROS 信号传播所需的中央 ROS 受体，系统信号响应不同的信号局部强光胁迫处理后，生物和非生物胁迫、局部组织的胁迫反应以及植物对胁迫的适应。我们进一步报道，HPCA1 是全身钙信号所必需的，但不是全身膜去极化反应所必需的，并确定了钙渗透通道机械敏感离子通道样 3、钙调磷酸酶 B 样钙传感器 4 (CBL4)、CBL4 相互作用蛋白激酶 26、以及细胞间 ROS 信号传播所需的蔗糖非发酵 1 相关蛋白激酶 2.6/OPEN STOMATA 1 (OST1)。此外，我们还发现 RBOHD 的丝氨酸残基 S343 和 S347（OST1 的推定靶标）在响应局部强光应激的细胞间 ROS 信号传导中发挥着关键作用。我们的研究结果表明，HPCA1 在介导和协调植物适应胁迫所需的系统细胞间 ROS 和钙信号方面发挥着关键作用。