Sinha S, Gupta M, Chandra P
Aquatic Botany Laboratory, National Botanical Research Institute, Lucknow, India.
Ecotoxicol Environ Saf. 1997 Dec;38(3):286-91. doi: 10.1006/eesa.1997.1598.
The effect of iron (FeCl3) on chlorophyll content, lipid peroxidation product, potassium ion leakage (a measure of damage to the permeability barrier), and antioxidants was studied in Hydrilla verticillata. The effect of iron-induced damage to the plant was compared with those of N-ethyl maleimide (NEM), a sulfhydryl reagent, and cumene hydroperoxide (CHP), an organic peroxide known to induce lipid peroxidation by free radical formation. The level of lipid peroxidation product was increased in the plants treated with Fe, CHP, and CHP + NEM but not with NEM alone. A significant increase in potassium ion leakage to the external solution was observed by the addition of Fe, CHP, and CHP + NEM, while this did not increase significantly in NEM-treated plants. When NEM and CHP were added simultaneously, the results were the same as those obtained with high iron concentrations, suggesting a combined effect of thiol depletion and lipid peroxidation by Fe ions. In addition, the results indicated loss of glutathione (GSH) and increased oxidized glutathione (GSSG) under Fe stress, indicative of oxidative stress. The oxidative stress may increase the production of free radicals and subsequently resulted in peroxidation of lipids. Further, addition of iron increased the activity of superoxide dismutase (SOD) which may be due to enhanced production of oxygen free radical and related tissue damage. The results suggest that iron-induced damage in plants can be ascribed to a direct metal action on thiols and by toxic oxygen species. An increase in lipid peroxidation product and K+ leakage are the primary responses of iron toxicity on membrane damage. However, the decrease in chlorophyll content is part of the overall expression of iron toxicity.
研究了铁（FeCl₃）对黑藻叶绿素含量、脂质过氧化产物、钾离子渗漏（衡量对渗透屏障的损伤程度）和抗氧化剂的影响。将铁诱导的植物损伤效应与N - 乙基马来酰亚胺（NEM，一种巯基试剂）和氢过氧化异丙苯（CHP，一种已知通过自由基形成诱导脂质过氧化的有机过氧化物）的效应进行了比较。在用铁、CHP和CHP + NEM处理的植物中，脂质过氧化产物水平升高，但单独用NEM处理的植物中未升高。添加铁、CHP和CHP + NEM后，观察到外部溶液中钾离子渗漏显著增加，而在NEM处理的植物中钾离子渗漏未显著增加。当同时添加NEM和CHP时，结果与高铁浓度下获得的结果相同，表明铁离子导致的巯基消耗和脂质过氧化具有联合效应。此外，结果表明在铁胁迫下谷胱甘肽（GSH）损失且氧化型谷胱甘肽（GSSG）增加，这表明存在氧化应激。氧化应激可能会增加自由基的产生，随后导致脂质过氧化。此外，添加铁会增加超氧化物歧化酶（SOD）的活性，这可能是由于氧自由基产生增加及相关组织损伤所致。结果表明，铁诱导的植物损伤可归因于金属对巯基的直接作用以及有毒氧物种的作用。脂质过氧化产物增加和K⁺渗漏是铁毒性对膜损伤的主要反应。然而，叶绿素含量降低是铁毒性总体表现的一部分。
