Kaya Cengiz, Murillo-Amador Bernardo, Ashraf Muhammad
Soil Science and Plant Nutrition Department, Agriculture Faculty, Harran University, Sanliurfa 6300, Turkey.
Centro de Investigaciones Biológicas del Noroeste, S.C. Avenida Instituto Politécnico Nacional No. 195, Colonia Playa Palo de Santa Rita Sur, La Paz 23096, Baja California Sur, Mexico.
Antioxidants (Basel). 2020 Jul 10;9(7):603. doi: 10.3390/antiox9070603.
The aim of this study is to assess the role of -cysteine desulfhydrase (-DES) and endogenous hydrogen sulfide (HS) in glutathione (GSH)-induced tolerance to salinity stress (SS) in sweet pepper ( L.). Two weeks after germination, before initiating SS, half of the pepper seedlings were retained for 12 h in a liquid solution containing HS scavenger, hypotaurine (HT), or the -DES inhibitor -propargylglycine (PAG). The seedlings were then exposed for three weeks to control or SS (100 mmol L NaCl) and supplemented with or without GSH or GSH+NaHS (sodium hydrosulfide, HS donor). Salinity suppressed dry biomass, leaf water potential, chlorophyll contents, maximum quantum efficiency, ascorbate, and the activities of dehydroascorbate reductase, monodehydroascorbate reductase, and glyoxalase II in plants. Contrarily, it enhanced the accumulation of hydrogen peroxide, malondialdehyde, methylglyoxal, electrolyte leakage, proline, GSH, the activities of glutathione reductase, peroxidase, catalase, superoxide dismutase, ascorbate peroxidase, glyoxalase I, and -DES, as well as endogenous HS content. Salinity enhanced leaf Na but reduced K; however, the reverse was true with GSH application. Overall, the treatments, GSH and GSH+NaHS, effectively reversed the oxidative stress and upregulated salt tolerance in pepper plants by controlling the activities of the AsA-GSH and glyoxalase-system-related enzymes as well as the levels of osmolytes.
本研究旨在评估β-半胱氨酸脱硫酶（β-DES）和内源性硫化氢（H₂S）在甜椒（Capsicum annuum L.）中谷胱甘肽（GSH）诱导的耐盐胁迫（SS）中的作用。发芽两周后，在开始盐胁迫之前，将一半的辣椒幼苗在含有H₂S清除剂次牛磺酸（HT）或β-DES抑制剂β-炔丙基甘氨酸（PAG）的液体溶液中保留12小时。然后将幼苗暴露于对照或盐胁迫（100 mmol L⁻¹ NaCl）三周，并补充或不补充GSH或GSH+NaHS（氢硫化钠，H₂S供体）。盐胁迫抑制了植物的干生物量、叶片水势、叶绿素含量、最大量子效率、抗坏血酸以及脱氢抗坏血酸还原酶、单脱氢抗坏血酸还原酶和乙二醛酶II的活性。相反，它增强了过氧化氢、丙二醛、甲基乙二醛、电解质渗漏、脯氨酸、GSH、谷胱甘肽还原酶、过氧化物酶、过氧化氢酶、超氧化物歧化酶、抗坏血酸过氧化物酶、乙二醛酶I和β-DES的活性以及内源性H₂S含量的积累。盐胁迫增加了叶片中的Na⁺但降低了K⁺；然而，施用GSH时情况则相反。总体而言，GSH和GSH+NaHS处理通过控制AsA-GSH和乙二醛酶系统相关酶的活性以及渗透调节物质的水平，有效地逆转了辣椒植株的氧化应激并上调了其耐盐性。
