College of Life Science, Northwest Normal University, Lanzhou, 730070, China.
Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, Lanzhou, 730000, China.
J Plant Res. 2020 May;133(3):393-407. doi: 10.1007/s10265-020-01182-3. Epub 2020 Mar 21.
Hydrogen sulfide (HS) 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 HS responding to osmotic stress and the functions of PLDα1 and ROS in this response were investigated. The results showed that HS, PLDα1 and ROS were involved in osmotic stress resistance. Exogenous sodium hydrosulfide (NaHS) promoted the endogenous HS content and up-regulated the expression of LCD in WT, lcd and plda1. Exogenous phosphatidic acid (PA) enhanced the HS content and up-regulated the expressions of LCD in WT and plda1 but had no significant effect on the HS content and LCD expression in lcd under osmotic stress. This suggested that HS 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 HS 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 HS maintained the membrane integrity. All of these results revealed that HS alleviated the osmotic stress by elevating PLD and suppressing ROS in A. thaliana.
硫化氢（HS）是一种响应植物渗透胁迫的重要气态分子。磷脂酶 Dα1（PLDα1）和活性氧（ROS）参与许多生物或非生物胁迫反应。本研究以拟南芥生态型（WT）、PLDα1 缺陷突变体（pldα1）和 L-半胱氨酸脱硫酶（L-DEs）缺陷突变体（lcd）的幼苗为材料，研究了 HS 响应渗透胁迫的作用以及 PLDα1 和 ROS 在该反应中的功能。结果表明，HS、PLDα1 和 ROS 参与了渗透胁迫抗性。外源硫氢化钠（NaHS）促进 WT、lcd 和 plda1 中内源性 HS 含量的增加，并上调 LCD 的表达。外源性磷脂酸（PA）增强了 WT 和 plda1 中的 HS 含量和 LCD 的表达，但对渗透胁迫下 lcd 中的 HS 含量和 LCD 表达无显著影响。这表明 HS 位于 PLDα1 的下游，参与渗透胁迫信号反应。外源 NaHS 处理调节抗氧化酶（SOD、POD 和 CAT）。在渗透胁迫下，plda1 和 lcd 中的抗氧化酶活性和基因相对表达高于 WT。这表明 HS 和 PLD 在渗透胁迫下调节抗氧化酶系统。ROS 水平、电解质渗漏（EL）和丙二醛（MDA）在渗透胁迫下被 NaHS 降低，表明 HS 维持了膜的完整性。这些结果表明，HS 通过提高 PLD 和抑制 ROS 缓解了 A. thaliana 的渗透胁迫。
