Abstract

The present work was conducted to assess the effects of arsenic (As, 1000 µM), diphenyleneiodonium (DPI, 10 µM) and reduced glutathione (GSH, 500 µM) on Isatis cappadocica. As treatment decreased plant growth and fresh and dry weight of shoot and root and also enhanced the accumulation of As. As stress also enhanced the oxidative stress biomarkers, hydrogen peroxide (H₂O₂) and malondialdehyde (MDA) content. However, the application of GSH decreased the content of H₂O₂ and MDA by 43% and 55%, respectively, as compared to As treatment. The antioxidants like superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), ascorbate peroxidase (APX), glutathione reductase (GR) and glutathione S-transferase (GST) also enhanced with As stress. NADPH oxidase inhibitor, the DPI, enhances the effect of As toxicity by increasing the accumulation of As, H₂O₂, MDA. DPI also enhances the activity of antioxidant enzymes except GR and GST, However, the application GSH increased the plant growth and biomass yield, decreases accumulation of As, H₂O₂ and MDA content in As as well as As + DPI treated plants. The thiols content [total thiol (TT), non-protein thiol (NPT) protein thiols (PT), and glutathione (GSH)] were decreased in the As + DPI treatment but supplementation of GSH enhanced them.

Novelty statement: The study reveals the beneficial role of GSH in mitigating the deleterious effects of Arsenic toxicity through its active involvement in the antioxidant metabolism, thiol synthesis and osmolyte accumulation. Apart from As, We provided the plants NADPH oxidase inhibitor, the diphenyleneiodonium (DPI), which boosts the As toxicity. At present, there is dearth of information pertaining to the effects of DPI on plants growth and their responses under heavy metal stress.

GSH application reversed the effect of diphenyleneiodonium (DPI) under As stress preventing the oxidative damage to biomolecules through the modulation of different antioxidant enzymes. The application of GSH for As stressed soil could be a sustainable approach for crop production.

摘要

目前的工作是评估砷 (As, 1000 µM)、二亚苯基碘 (DPI, 10 µM) 和还原型谷胱甘肽 (GSH, 500 µM) 对卡帕多西卡的影响。由于处理降低了植物生长以及地上部和根的鲜重和干重，并且还增加了砷的积累。由于压力还增强了氧化应激生物标志物、过氧化氢 (H ₂ O ₂ ) 和丙二醛 (MDA) 的含量。然而，GSH的应用降低了H ₂ O ₂的含量和 MDA 分别比 As 处理高 43% 和 55%。超氧化物歧化酶 (SOD)、过氧化氢酶 (CAT)、过氧化物酶 (POD)、抗坏血酸过氧化物酶 (APX)、谷胱甘肽还原酶 (GR) 和谷胱甘肽 S-转移酶 (GST) 等抗氧化剂也随着砷胁迫而增强。NADPH 氧化酶抑制剂 DPI 通过增加 As、H ₂ O ₂、MDA的积累来增强 As 毒性的作用。DPI 还增强了除 GR 和 GST 之外的抗氧化酶的活性，但施用 GSH 增加了植物生长和生物量产量，减少了 As、H ₂ O _{2 的}积累As 以及 As + DPI 处理的植物中的 MDA 含量。硫醇含量 [总硫醇 (TT)、非蛋白质硫醇 (NPT)、蛋白质硫醇 (PT) 和谷胱甘肽 (GSH)] 在 As + DPI 处理中降低，但补充 GSH 会增强它们。

新颖性声明：该研究揭示了 GSH 通过其积极参与抗氧化剂代谢、硫醇合成和渗透剂积累，在减轻砷毒性的有害影响方面的有益作用。除了 As，我们还提供了植物 NADPH 氧化酶抑制剂二亚苯基碘鎓 (DPI)，可增强 As 毒性。目前，缺乏有关 DPI 对植物生长的影响及其在重金属胁迫下的反应的信息。

GSH的应用逆转了As胁迫下二苯碘鎓（DPI）的作用，通过调节不同的抗氧化酶来防止对生物分子的氧化损伤。在砷胁迫的土壤中应用 GSH 可能是一种可持续的作物生产方法。