College of Life Science, Northwest Normal University, Lanzhou, 730070, China.
College of Life Science, Northwest Normal University, Lanzhou, 730070, China.
Biochem Biophys Res Commun. 2021 Jan 1;534:914-920. doi: 10.1016/j.bbrc.2020.10.074. Epub 2020 Nov 10.
Osmotic stress is one of the main stresses seriously affects the growth and development of plants. Hydrogen sulfide (HS) emerges as the third gaseous signal molecule to involve in the complex network of signaling events. Phospholipase Dδ (PLDδ), as signal enzyme, responds to many biotic or abiotic stress responses. In this study, the functions and the relationship of PLDδ and HS in stomatal closure induced by osmotic stress were explored. Using the seedlings of ecotype (WT), PLDδ deficient mutant (pldδ), L-cysteine desulfhydrase (LCD) deficient mutant (lcd) and pldδlcd double mutant as materials, the Real-time quantitative PCR (RT-qPCR) and the stomatal aperture were analyzed. Osmotic stress induced the expressions of PLDδ and LCD. The HS content and the activities of PLD and LCD ascended in WT under osmotic stress. The phenotypes of pldδ, lcd and pldδlcd were more sensitive to osmotic stress than WT. Compared with pldδ, the stomatal of lcd showed lower sensitivity to osmotic stress, and the stomatal aperture of pldδlcd was similar to that of lcd. Simultaneous application of PA and NaHS resulted in tighter closure of stomatal than application of either PA or NaHS alone. These results suggested that osmotic stress-triggered stomatal closure requires PLDδ and HS in A. thaliana. LCD acted downstream of PLDδ to regulate the stomatal closure induced by osmotic stress.
渗透胁迫是严重影响植物生长和发育的主要胁迫之一。硫化氢（HS）作为第三种气态信号分子，参与到复杂的信号事件网络中。磷脂酶 Dδ（PLDδ）作为信号酶，响应许多生物或非生物胁迫反应。在这项研究中，探索了 PLDδ 和 HS 在渗透胁迫诱导的气孔关闭中的功能和关系。使用生态型（WT）、PLDδ 缺陷突变体（pldδ）、L-半胱氨酸脱硫酶（LCD）缺陷突变体（lcd）和 pldδlcd 双突变体的幼苗作为材料，分析了实时定量 PCR（RT-qPCR）和气孔孔径。渗透胁迫诱导了 PLDδ 和 LCD 的表达。在渗透胁迫下，WT 中 HS 含量和 PLD 和 LCD 的活性上升。pldδ、lcd 和 pldδlcd 的表型比 WT 对渗透胁迫更敏感。与 pldδ 相比，lcd 的气孔对渗透胁迫的敏感性较低，pldδlcd 的气孔孔径与 lcd 相似。同时施加 PA 和 NaHS 导致的气孔关闭比单独施加 PA 或 NaHS 更紧密。这些结果表明，渗透胁迫诱导的气孔关闭需要拟南芥中的 PLDδ 和 HS。LCD 作为 PLDδ 的下游因子，调节渗透胁迫诱导的气孔关闭。
