镉 (Cd) 是一种非必需的剧毒元素，在浓度相当低的情况下就会对植物、人类和动物构成潜在的健康威胁。由于镉的高流动性，植物可以从土壤和水中吸收镉。本文综述了植物对镉药害的反应以及镉耐受机制。镉毒性在植物中的普遍反应是 DNA 损伤、基因表达改变、细胞分裂和细胞死亡，从而导致代谢、解剖和形态改变，包括蛋白质降解、水分和养分吸收降低、失绿、光合作用抑制、和农作物产量损失。植物拥有一系列机制，如细胞壁结合、减少转运、液泡分隔以及解毒过程中与金属硫蛋白或植物螯合素的螯合，从而对镉具有耐受性。一些植物发展出结构和遗传适应以实现对镉的耐受性。植物抗氧化防御系统的激活和激素水平的调节、次生代谢物的改变以及更高的矿物质营养可以缓解镉胁迫。还讨论了目前关于镉胁迫影响的知识状况以及避免损害和开发抗镉作物的可能管理策略。

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Cadmium (Cd) is a non-essential highly toxic element that poses a potential health threat for plants, humans, and animals at considerably smaller concentrations. Plants can uptake Cd from soil and water due to its high mobility. In this review, the plant responses towards Cd phytotoxicity and the mechanism of Cd tolerance are summarized. Prevalent responses of Cd toxicity in plants are DNA damage, alteration in gene expression, cell division, and cell death which lead to metabolic, anatomic, and morphological modifications ranging from protein degradation to lower uptake of water and nutrients, chlorosis, inhibition of photosynthesis, and crop yield losses. Plants possess an array of mechanisms like cell wall binding, reduced transport, compartmentation in the vacuole, and chelation with metallothioneins, or phytochelatins in the detoxification and thus tolerance to Cd. Some plants develop structural and genetic adaption to achieve tolerance to Cd. Activation of plant antioxidative defense system and modulation of hormonal levels, alteration of secondary metabolites, and higher mineral nutrition triggers alleviation of Cd stress. The current state of knowledge on the effect of Cd stress and possible management strategies to avert damage and develop Cd-resistant crops have also been discussed.