Institute of Environment, Resource, Soil and Fertilizer, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China.
Key Laboratory of Environment Remediation and Ecological Health, Ministry of Education, Hangzhou 310058, China.
Int J Mol Sci. 2019 Jun 18;20(12):2960. doi: 10.3390/ijms20122960.
Salicylic acid (SA), as an enigmatic signalling molecule in plants, has been intensively studied to elucidate its role in defence against biotic and abiotic stresses. This review focuses on recent research on the role of the SA signalling pathway in regulating cadmium (Cd) tolerance in plants under various SA exposure methods, including pre-soaking, hydroponic exposure, and spraying. Pretreatment with appropriate levels of SA showed a mitigating effect on Cd damage, whereas an excessive dose of exogenous SA aggravated the toxic effects of Cd. SA signalling mechanisms are mainly associated with modification of reactive oxygen species (ROS) levels in plant tissues. Then, ROS, as second messengers, regulate a series of physiological and genetic adaptive responses, including remodelling cell wall construction, balancing the uptake of Cd and other ions, refining the antioxidant defence system, and regulating photosynthesis, glutathione synthesis and senescence. These findings together elucidate the expanding role of SA in phytotoxicology.
水杨酸（SA）作为植物中一种神秘的信号分子，其在植物防御生物和非生物胁迫方面的作用已得到深入研究。本综述重点介绍了在各种 SA 暴露方法下，SA 信号通路在调节植物镉（Cd）耐受性方面的最新研究进展，包括预浸泡、水培暴露和喷雾。适当水平的 SA 预处理对 Cd 损伤表现出缓解作用，而过量的外源 SA 则加剧了 Cd 的毒性作用。SA 信号机制主要与植物组织中活性氧（ROS）水平的修饰有关。然后，ROS 作为第二信使，调节一系列生理和遗传适应性反应，包括重塑细胞壁结构、平衡 Cd 和其他离子的摄取、优化抗氧化防御系统以及调节光合作用、谷胱甘肽合成和衰老。这些发现共同阐明了 SA 在植物毒理学中的作用不断扩大。
