Key Laboratory of Marine Food Quality and Hazard Controlling Technology of Zhejiang Province, College of Life Sciences, China Jiliang University; Hangzhou, 310018, China.
Key Laboratory of Marine Food Quality and Hazard Controlling Technology of Zhejiang Province, College of Life Sciences, China Jiliang University; Hangzhou, 310018, China.
Ecotoxicol Environ Saf. 2021 Jan 1;207:111198. doi: 10.1016/j.ecoenv.2020.111198. Epub 2020 Sep 6.
Cd pollution in farmland is becoming a serious problem because it affects the safety of rice production and human health. Salicylic acid (SA) plays crucial roles in plant development and mediates plant responses to biotic and abiotic stress. This study assessed the molecular and physiological mechanisms of SA spraying effects on Cd tolerance and Cd accumulation in rice. Spraying of 0.1 mM SA had no great effect on the agronomic traits of rice, but significantly decreased Cd accumulation in rice grains, and SA spraying increased the Cd contents in leaves (only at the mature stage) and decreased the Cd contents in panicles (only at the filling and mature stage), but had no evident impact on the Cd content of other tissues and other growth stages. SA spraying reduced Cd accumulation in rice grains by promoting the deposition and fixation of Cd in the cell wall of leaves, thus preventing Cd being transferred from leaves to rice grains at the filling stage. SA spraying also decreased Cd toxicity by reducing HO and MDA accumulation and increasing the chlorophyll content in rice leaves. Furthermore, SA spraying remarkably decreased Cd accumulation in rice grains by modulating the expression level of the genes associated with Cd translocation and accumulation to control the Cd accumulation in rice. Hence, SA spraying reduced the inhibition of Cd on the plant height caused by Cd and increased the dry weight of shoots in the vegetative growth period of rice seedlings, and it reduced Cd transport from leaves to grains, thus reducing Cd content in rice. These findings provide a novel perspective and a new method for reducing Cd accumulation in rice.
农田镉污染正成为一个严重的问题，因为它影响到水稻生产的安全和人类健康。水杨酸（SA）在植物发育中起着至关重要的作用，并介导植物对生物和非生物胁迫的反应。本研究评估了喷施 SA 对水稻 Cd 耐性和 Cd 积累的分子和生理机制。喷施 0.1mM SA 对水稻的农艺性状没有很大影响，但显著降低了水稻籽粒中的 Cd 积累，SA 喷施增加了叶片中的 Cd 含量（仅在成熟阶段），降低了穗中的 Cd 含量（仅在灌浆和成熟阶段），但对其他组织和其他生长阶段的 Cd 含量没有明显影响。SA 喷施通过促进 Cd 在叶片细胞壁中的沉积和固定，从而阻止 Cd 在灌浆期从叶片向水稻籽粒转移，减少了水稻籽粒中的 Cd 积累。SA 喷施还通过减少 HO 和 MDA 积累，增加叶片中叶绿素含量，降低 Cd 毒性。此外，SA 喷施通过调节与 Cd 转运和积累相关的基因的表达水平，显著减少了水稻籽粒中的 Cd 积累，从而控制了水稻中的 Cd 积累。因此，SA 喷施减少了 Cd 对 Cd 抑制的抑制作用，增加了水稻幼苗营养生长期地上部分的干重，并减少了 Cd 从叶片向籽粒的运输，从而降低了稻米中的 Cd 含量。这些发现为减少水稻中的 Cd 积累提供了新的视角和新方法。
