Xiao Yuansong, Wu Xuelian, Sun Maoxiang, Peng Futian
State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai'an, China.
Front Plant Sci. 2020 May 29;11:696. doi: 10.3389/fpls.2020.00696. eCollection 2020.
Peach ( L. Batsch) is a shallow root fruit tree with poor waterlogging tolerance. Hydrogen sulfide (HS) is a signal molecule which regulates the adaptation of plants to adverse environments. Nevertheless, the effects of exogenous applications of HS in fruit tree species especially in peach trees under waterlogging stress have been scarcely researched. Thus, the goal of this research was to investigate the alleviating effect of exogenous HS on peach seedlings under waterlogging stress. In the present study, we found that the effect of exogenous HS depended on the concentration and 0.2 mM sodium hydrosulfide (NaHS) showed the best remission effect on peach seedlings under waterlogging stress. Waterlogging significantly reduced the stomatal opening, net photosynthetic rate, and Fv/Fm of peach seedlings. The results of histochemical staining and physiological and biochemical tests showed that waterlogging stress increased the number of cell deaths and amounts of reactive oxygen species (ROS) accumulated in leaves, increased the number of root cell deaths, significantly increased the electrolyte permeability, O. production rate, HO content and ethylene synthesis rate of roots, and significantly reduced root activity. With prolonged stress, antioxidative enzyme activity increased initially and then decreased. Under waterlogging stress, application of 0.2 mM NaHS increased the number of stomatal openings, improved the chlorophyll content, and photosynthetic capacity of peach seedlings. Exogenous HS enhanced antioxidative system and significantly alleviate cell death of roots and leaves of peach seedlings caused by waterlogging stress through reducing ROS accumulation in roots and leaves. HS can improve the activity and proline content of roots, reduce oxidative damage, alleviated lipid peroxidation, and inhibit ethylene synthesis. The HS scavenger hypotaurine partially eliminated the effect of exogenous HS on alleviating waterlogging stress of peach seedlings. Collectively, our results provide an insight into the protective role of HS in waterlogging-stressed peach seedlings and suggest HS as a potential candidate in reducing waterlogging-induced damage in peach seedlings.
桃（L. Batsch）是一种浅根果树，耐涝性差。硫化氢（HS）是一种调节植物对逆境环境适应性的信号分子。然而，外源施用HS对果树尤其是淹水胁迫下桃树的影响鲜有研究。因此，本研究的目的是探讨外源HS对淹水胁迫下桃幼苗的缓解作用。在本研究中，我们发现外源HS的作用取决于浓度，0.2 mM硫氢化钠（NaHS）对淹水胁迫下的桃幼苗显示出最佳的缓解效果。淹水显著降低了桃幼苗的气孔开度、净光合速率和Fv/Fm。组织化学染色以及生理生化测试结果表明，淹水胁迫增加了叶片中细胞死亡数量和活性氧（ROS）积累量，增加了根细胞死亡数量，显著提高了根的电解质渗透率、O.产生速率、HO含量和乙烯合成速率，并显著降低了根活性。随着胁迫时间延长，抗氧化酶活性先升高后降低。在淹水胁迫下，施用0.2 mM NaHS增加了气孔开度，提高了桃幼苗的叶绿素含量和光合能力。外源HS增强了抗氧化系统，并通过减少根和叶中ROS的积累，显著缓解了淹水胁迫引起的桃幼苗根和叶的细胞死亡。HS可以提高根的活性和脯氨酸含量，减少氧化损伤，减轻脂质过氧化，并抑制乙烯合成。HS清除剂次牛磺酸部分消除了外源HS对缓解桃幼苗淹水胁迫的作用。总的来说，我们的结果揭示了HS在淹水胁迫桃幼苗中的保护作用，并表明HS是减轻桃幼苗淹水诱导损伤的潜在候选物质。
