Hydrogen sulfide (H2S) is an important gaseous molecule responding to osmotic stress in plant. Phospholipase Dα1 (PLDα1) and reactive oxygen species (ROS) are involved in many biotic or abiotic stress responses. Using the seedlings of Arabidopsis thaliana ecotype (WT), PLDα1 deficient mutant (pldα1) and the L-cysteine desulfhydrase (L-DEs) deficient mutant (lcd) as materials, the effect of H2S responding to osmotic stress and the functions of PLDα1 and ROS in this response were investigated. The results showed that H2S, PLDα1 and ROS were involved in osmotic stress resistance. Exogenous sodium hydrosulfide (NaHS) promoted the endogenous H2S content and up-regulated the expression of LCD in WT, lcd and plda1. Exogenous phosphatidic acid (PA) enhanced the H2S content and up-regulated the expressions of LCD in WT and plda1 but had no significant effect on the H2S content and LCD expression in lcd under osmotic stress. This suggested that H2S was located downstream of PLDα1 to participate in the osmotic stress signal response. Exogenous NaHS treatment regulated the antioxidant enzymes (SOD, POD, and CAT). The activities and the gene relative expressions of antioxidant enzymes in pldα1 and lcd were higher than those in WT under osmotic stress. This indicated that H2S and PLD regulated the antioxidant enzyme system under osmotic stress. The ROS level, electrolyte leakage (EL), malondialdehyde (MDA) were decreased by NaHS under osmotic stress, demonstrating H2S maintained the membrane integrity. All of these results revealed that H2S alleviated the osmotic stress by elevating PLD and suppressing ROS in A. thaliana.

中文翻译：

---

H2S减轻渗透胁迫与拟南芥中PLDα1的调节和ROS的抑制有关。

硫化氢（H2S）是一种重要的气体分子，对植物体内的渗透胁迫有反应。磷脂酶Dα1（PLDα1）和活性氧（ROS）参与许多生物或非生物胁迫反应。以拟南芥生态型（WT），PLDα1缺陷型突变体（pldα1）和L-半胱氨酸脱硫酶（L-DEs）缺陷型突变体（lcd）的幼苗为材料，H2S对渗透胁迫的响应以及PLDα1和PLDα1的功能研究了这种反应中的ROS。结果表明，H2S，PLDα1和ROS与渗透胁迫抗性有关。外源性硫化氢钠（NaHS）促进内源性H2S含量并上调LCD在WT，lcd和plda1中的表达。外源性磷脂酸（PA）提高了WT和plda1中H2S的含量，上调了LCD的表达，但对渗透胁迫下lcd中的H2S和LCD的表达没有显着影响。这表明H2S位于PLDα1的下游以参与渗透胁迫信号响应。外源NaHS处理可调节抗氧化酶（SOD，POD和CAT）。在渗透胁迫下，pldα1和lcd中抗氧化酶的活性和基因相对表达均高于野生型。这表明H2S和PLD在渗透胁迫下调节抗氧化酶系统。NaHS在渗透胁迫下降低了ROS水平，电解质泄漏（EL），丙二醛（MDA），表明H2S保持了膜的完整性。