College of Life Science, Nanjing Normal University, Nanjing 210023, China.
College of Life Science, Nanjing Normal University, Nanjing 210023, China.
Ecotoxicol Environ Saf. 2018 Jan;147:500-508. doi: 10.1016/j.ecoenv.2017.09.015. Epub 2017 Sep 14.
Cadmium (Cd) is a significant environmental pollutant in the aquatic environment. Salicylic acid (SA) is a ubiquitous phenolic compound. The goal of this study was to assess the morphological, physiological and biochemical changes in duckweed (L. minor) upon exposure to 10μM CdCl, 10μM CdCl plus 50μM SA, or 50μM SA for 7 days. Reversing the effects of Cd, SA decreased Cd accumulation in plants, improved accumulation of minerals (Ca, Mg, Fe, B, Mo) absorption, increased endogenous SA concentration, and phenylalanine ammonialyase (PAL) activity. Chlorosis-associated symptoms, the reduction in chlorophyll content, and the overproduction of reactive oxygen species induced by Cd exposure were largely reversed by SA. SA significantly decreased the toxic effects of Cd on the activities of the superoxide dismutase, peroxidase, catalase, ascorbate peroxidase, and glutathione reductase in the fronds of L. minor. Furthermore, SA reversed the detrimental effects of Cd on total ascorbate, glutathione, the ascorbic acid/oxidized dehydroascorbate and glutathione/glutathione disulphide ratios, lipid peroxidation, malondialdehyde concentration, lipoxygenase activity, and the accumulation of proline. SA induced the up-regulation of heat shock proteins (Hsp70) and attenuated the adverse effects of Cd on cell viability. These results suggest that SA confers tolerance to Cd stress in L. minor through different mechanisms.
镉（Cd）是水生环境中一种重要的环境污染物。水杨酸（SA）是一种普遍存在的酚类化合物。本研究的目的是评估浮萍（L. minor）在暴露于 10μM CdCl、10μM CdCl 和 50μM SA 或 50μM SA 7 天后形态、生理和生化变化。SA 逆转了 Cd 的作用，降低了植物中 Cd 的积累，增加了矿物质（Ca、Mg、Fe、B、Mo）的吸收，提高了内源 SA 浓度和苯丙氨酸解氨酶（PAL）活性。SA 显著减轻了 Cd 暴露引起的浮萍叶片黄化相关症状、叶绿素含量降低和活性氧过度产生。SA 显著降低了 Cd 对浮萍叶片中超氧化物歧化酶、过氧化物酶、过氧化氢酶、抗坏血酸过氧化物酶和谷胱甘肽还原酶活性的毒性作用。此外，SA 逆转了 Cd 对总抗坏血酸、谷胱甘肽、抗坏血酸/氧化脱氢抗坏血酸和谷胱甘肽/谷胱甘肽二硫化物比值、脂质过氧化、丙二醛浓度、脂氧合酶活性和脯氨酸积累的不利影响。SA 诱导热休克蛋白（Hsp70）的上调，并减轻了 Cd 对细胞活力的不利影响。这些结果表明，SA 通过不同的机制赋予浮萍对 Cd 胁迫的耐受性。
