Protective roles of salicylic acid in maintaining integrity and functions of photosynthetic photosystems for alfalfa (Medicago sativa L.) tolerance to aluminum toxicity
Protective roles of salicylic acid in maintaining integrity and functions of photosynthetic photosystems for alfalfa (Medicago sativa L.) tolerance to aluminum toxicity
复制标题
水杨酸在维持紫花苜蓿（Medicago sativa L.）对铝毒性耐受性的光合光系统完整性和功能方面的保护作用
DOI：
10.1016/j.plaphy.2020.08.028
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发表时间：
2020-10-01
影响因子：
6.5
通讯作者：
Zhou, Peng
中科院分区：
文献类型：
--
作者：
Cheng, Xiaoqing;Fang, Tingyu;Zhou, Peng
在铝污染的地区，铝（Al）可能对植物生长有害。研究了水杨酸（SA）对紫花苜蓿（Medicago sativa L.）叶绿体和光合系统的铝毒害作用，并探讨了SA对植物耐铝性的影响。在水培系统中用Al（100 μ M）处理植物3天。铝处理叶片中铝含量增加，导致叶绿体损伤变形。铝胁迫下，叶绿体被膜和淀粉粒消失，片层和基质片层排列疏松，基粒数量减少，出现大量小质体。叶面喷施15 μ M SA可降低根、叶中铝含量，减轻叶绿体铝损伤。经15 μ M SA处理后，叶绿体形状恢复为扁椭圆形，类囊体排列紧密，有规则的排列，叶绿体中淀粉粒完整，小的质体颗粒消失。SA处理的植物有显着较高的地上生物量比未经处理的对照暴露于铝胁迫。光合指数和基因表达分析表明，SA可通过提高光捕获效率、促进光合电子传递链中的电子传递和类囊体腔的脱酸、促进腺苷三磷酸（ATP）和烟酰胺腺嘌呤二核苷酸磷酸（NADPH）的合成来减轻铝毒的不利影响。SA对维持植物光合作用系统的完整性和功能具有保护作用。
Aluminum (Al) can be detrimental to plant growth in areas with Al contamination. The objective of this study was to determine whether salicylic acid (SA) can improve plant tolerance to Al stress by mitigating Al toxicity for chloroplasts and photosynthetic systems in alfalfa (Medicago sativa L.). Plants were treated with Al (100 mu M) for 3 d in a hydroponic system. The content of Al increased in leaves treated with Al, resulting in damage and deformation of chloroplasts. In Al-damaged leaves, chloroplast envelopes and starch granules disappeared; the lamellae and stroma lamella were loosely arranged and indistinguishable, and the number of grana was reduced; a large number of small plastoglobules appeared. Foliar spraying of 15 mu M SA reduced Al content in roots and leaves and alleviated Al damages in chloroplasts. With 15 mu M SA treatments, the chloroplast shape returned to a flat ellipsoid, thylakoids were arranged closely and regularly, chloroplasts had intact starch granules, and small plastoglobules disappeared. SA-treated plants had significantly higher aboveground biomass than the untreated control exposed to Al stress. Photosynthetic index and gene expression analyses demonstrated that SA could alleviate adverse effects of Al toxicity by increasing light capture efficiency, promoting electron transport in the photosynthetic electron transport chain and thylakoid lumen deacidification, and promoting synthesis of aenosine triphosphate (ATP) and nicotinamide adenine dinucleotide phosphate (NADPH). SA played protective roles in maintaining integrity and functions of photosystems in photosynthesis for plant tolerance to Al stress.