Ranjan Plant Physiology and Biochemistry Laboratory, Department of Botany, University of Allahabad, Prayagraj, U.P., 211002, India.
Plant Physiol Biochem. 2021 Jul;164:173-184. doi: 10.1016/j.plaphy.2021.05.001. Epub 2021 May 6.
In the present study, the role of hydrogen sulfide (HS) in alleviating NaCl (20 mM) induced toxicity on growth, photosynthetic pigments and photochemistry of PS II, and impact on oxidative stress and antioxidant systems of eggplant and tomato was studied. To confirm the role of HS (donor sodium hydrogen sulphide (NaHS; 40 μM)) under stress, HS scavenger; hypotaurine (HT; 200 μM) and inhibitor, propargylglycine (PAG; 100 μM) in combination with NaHS was added to the growth medium of NaCl stressed seedlings. The NaCl reduced the overall growth of the seedlings as the Na uptake was increased which led to removal of K, thereby Na/K homeostasis was disturbed. This condition caused severe impact on photosynthetic pigments and PS II photochemistry, thus significant decline in the values of fluorescence kinetics parameters such as F/F, F/F, φE, ѱ PI except F/F and enhancement in energy flux parameters such as ABS/RC, TR/RC, ET/RC and DI/RC was obtained. Exogenous HS not only abolished the toxic symptoms in test seedlings but also completely alleviated the decline in growth in case of tomato seedlings. Reactive oxygen species accumulation was significantly declined in both the seedlings as evident by in vitro and in vivo analysis with the supplementation of NaHS, indicating appreciable recovery in membrane damage caused by NaCl toxicity. Antioxidative enzymes: SOD, POD, CAT and GST activities were further stimulated in response to HS (NaHS) supplementation to the stressed seedlings, thus maintaining the redox homeostasis of cell and bringing the seedlings back to the healthy state. Moreover, the role of endogenous and exogenous HS was also justified using the scavenger of HS (HT; 200 μM) and inhibitor of enzymes of HS (PAG; 100 μM). Thus, present study emphasizes the role of NaHS as HS donor in alleviating NaCl stress in crops particularly vegetables tomato and eggplant, and may be considered as a part of important strategies to cope up with NaCl toxicity which is prevailing in natural field condition.
在本研究中，研究了硫化氢 (HS) 在缓解 NaCl（20 mM）对茄子和番茄生长、光合色素和 PS II 光化学的毒性中的作用，以及对氧化应激和抗氧化系统的影响。为了证实 HS（供体硫氢化钠 (NaHS；40 μM）在胁迫下的作用，将 HS 清除剂；高半胱氨酸 (HT；200 μM）和抑制剂炔丙基甘氨酸 (PAG；100 μM）添加到 NaCl 胁迫幼苗的生长介质中。随着 Na 吸收的增加，NaCl 降低了幼苗的整体生长，导致 K 的去除，从而破坏了 Na/K 平衡。这种情况对光合色素和 PS II 光化学产生了严重影响，因此荧光动力学参数的数值如 F/F、F/F、φE、ѱ PI 除了 F/F 显著下降，能量通量参数如 ABS/RC、TR/RC、ET/RC 和 DI/RC 得到增强。外源性 HS 不仅消除了试验幼苗的毒性症状，而且完全缓解了番茄幼苗的生长下降。ROS 积累在两种幼苗中均显著下降，这表明在体外和体内分析中，补充 NaHS 可明显减轻 NaCl 毒性引起的膜损伤。抗氧化酶：SOD、POD、CAT 和 GST 活性在 HS（NaHS）补充到胁迫幼苗后进一步受到刺激，从而维持细胞的氧化还原平衡，并使幼苗恢复健康状态。此外，还使用 HS 的清除剂（HT；200 μM）和 HS 酶的抑制剂（PAG；100 μM）来验证内源性和外源性 HS 的作用。因此，本研究强调了 NaHS 作为 HS 供体在缓解作物特别是蔬菜番茄和茄子中 NaCl 胁迫中的作用，并且可以被认为是应对普遍存在于自然田间条件下的 NaCl 毒性的重要策略的一部分。
