The effects of four liquid modifiers (organic–inorganic composite modifier, inorganic polymer compound modifier, polyacrylate compound modifier, and organic polymer compound modifier) on plant growth, cadmium (Cd) content, photosynthetic parameters and antioxidant enzymes were studied in cotton (Xinluzao) under Cd stress (5 mg kg−1) in a barrel experiment. The results showed that the Cd treatment of soil increased Cd content in cotton and reduced plant height, net photosynthesis rate (Pn), chlorophyll fluorescence parameters, antioxidant enzyme activity, and biomass. However, the application of liquid modifiers alleviated Cd stress, increased plant biomass, and decreased Cd content in plant organs as well as Cd transport coefficients of the stem and cottonseed. At the same time, there was an increase in gas exchange, photosynthetic pigment content, superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) activity in cotton leaves, whereas malondialdehyde content (MDA) decreased. These results suggest a positive role of liquid modifiers in alleviating Cd stress in cotton, which was due to (1) significant reduction in Cd uptake of roots and Cd-transportation to leaves and (2) improvement in the antioxidant activity, which regulated the oxidants to a level under control, minimizing the oxidative damage in cotton.

中文翻译：

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改性剂对镉毒害下棉花生长、光合作用及抗氧化酶的影响

研究了四种液体改性剂（有机-无机复合改性剂、无机高分子复合改性剂、聚丙烯酸酯复合改性剂和有机高分子复合改性剂）对棉花（新陆早）植物生长、镉（Cd）含量、光合参数和抗氧化酶的影响在桶实验中在 Cd 应力 (5 mg kg-1) 下。结果表明，土壤镉处理增加了棉花中的镉含量，降低了株高、净光合速率（Pn）、叶绿素荧光参数、抗氧化酶活性和生物量。然而，液体改性剂的应用减轻了镉胁迫，增加了植物生物量，降低了植物器官中的镉含量以及茎和棉籽的镉转运系数。同时，气体交换、光合色素含量增加，棉花叶片中的超氧化物歧化酶 (SOD)、过氧化氢酶 (CAT) 和过氧化物酶 (POD) 活性，而丙二醛含量 (MDA) 降低。这些结果表明液体改性剂在减轻棉花 Cd 胁迫中的积极作用，这是由于 (1) 显着减少根对 Cd 的吸收和 Cd 向叶片的运输和 (2) 提高抗氧化活性，从而调节氧化剂控制水平，最大限度地减少棉花的氧化损伤。