Hebei Key Laboratory of Molecular and Cellular Biology, College of Life Science, Hebei Normal University, Shijiazhuang, 050024, China; Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.
Plant Cell Environ. 2014 Jul;37(7):1548-60. doi: 10.1111/pce.12259. Epub 2014 Jan 21.
Multiple cellular events like dynamic actin reorganization and hydrogen peroxide (H(2)O(2)) production were demonstrated to be involved in abscisic acid (ABA)-induced stomatal closure. However, the relationship between them as well as the underlying mechanisms remains poorly understood. Here, we showed that H(2)O(2) generation is indispensable for ABA induction of actin reorganization in guard cells of Arabidopsis that requires the presence of ARP2/3 complex. H(2)O(2) -induced stomatal closure was delayed in the mutants of arpc4 and arpc5, and the rate of actin reorganization was slowed down in arpc4 and arpc5 in response to H(2)O(2), suggesting that ARP2/3-mediated actin nucleation is required for H(2)O(2) -induced actin cytoskeleton remodelling. Furthermore, the expression of H(2)O(2) biosynthetic related gene AtrbohD and the accumulation of H(2)O(2) was delayed in response to ABA in arpc4 and arpc5, demonstrating that misregulated actin dynamics affects H(2)O(2) production upon ABA treatment. These results support a possible causal relation between the production of H(2)O(2) and actin dynamics in ABA-mediated guard cell signalling: ABA triggers H(2)O(2) generation that causes the reorganization of the actin cytoskeleton partially mediated by ARP2/3 complex, and ARP2/3 complex-mediated actin dynamics may feedback regulate H(2)O(2) production.
多种细胞事件，如动态肌动蛋白重组和过氧化氢（H₂O₂）的产生，被证明参与脱落酸（ABA）诱导的气孔关闭。然而，它们之间的关系以及潜在的机制仍知之甚少。在这里，我们表明 H₂O₂ 的产生对于 ABA 诱导拟南芥保卫细胞肌动蛋白重组是必不可少的，这需要 ARP2/3 复合物的存在。在 arpc4 和 arpc5 的突变体中，H₂O₂ 诱导的气孔关闭被延迟，并且在 H₂O₂ 响应中，arpc4 和 arpc5 中的肌动蛋白重组速度减慢，表明 ARP2/3 介导的肌动蛋白成核是 H₂O₂ 诱导肌动蛋白细胞骨架重塑所必需的。此外，在 arpc4 和 arpc5 中，H₂O₂ 生物合成相关基因 AtrbohD 的表达和 H₂O₂ 的积累对 ABA 的反应延迟，表明失调的肌动蛋白动力学会影响 ABA 处理时的 H₂O₂ 产生。这些结果支持了 ABA 介导的保卫细胞信号中 H₂O₂ 产生和肌动蛋白动力学之间可能存在因果关系：ABA 触发 H₂O₂ 的产生，导致肌动蛋白细胞骨架的重组，部分由 ARP2/3 复合物介导，而 ARP2/3 复合物介导的肌动蛋白动力学可能反馈调节 H₂O₂ 的产生。
