Application of exogenous salicylic acid reduces Cd toxicity and Cd accumulation in rice
Application of exogenous salicylic acid reduces Cd toxicity and Cd accumulation in rice
复制标题
施用外源水杨酸降低水稻Cd毒性和Cd积累
DOI：
10.1016/j.ecoenv.2020.111198
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发表时间：
2021-01-01
影响因子：
6.8
通讯作者：
Zhu, Cheng
中科院分区：
文献类型：
--
作者：
Wang, Feijuan;Tan, Haifeng;Zhu, Cheng
农田镉污染已成为影响水稻生产安全和人类健康的严重问题。水杨酸（SA）在植物生长发育中起着重要作用，并介导植物对生物和非生物胁迫的响应。本研究探讨了水杨酸对水稻镉耐性和镉积累影响的分子和生理机制。喷施0.1 mM SA对水稻农艺性状影响不大，但显著降低了水稻籽粒中Cd的积累量，SA处理提高了叶片中Cd含量（仅在成熟期），降低了穗中Cd含量（仅在灌浆期和成熟期），但对其他组织和生育期的Cd含量影响不明显。喷施水杨酸（SA）可促进Cd在水稻叶片细胞壁的沉积和固定，从而减少Cd在水稻籽粒中的积累，阻止Cd在灌浆期从叶片向籽粒的转移。喷施水杨酸还可通过减少H2O2和MDA的积累，提高叶绿素含量，减轻Cd对水稻的毒害。此外，SA还通过调控水稻Cd转运和积累相关基因的表达水平，控制水稻Cd积累，从而显著降低水稻Cd积累。因此，喷施SA减轻了Cd对水稻株高的抑制作用，增加了水稻幼苗营养生长期地上部干重，减少了Cd从叶片向籽粒的转运，从而降低了水稻体内Cd含量。这些研究结果为减少水稻镉积累提供了新的视角和新的方法。
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 pre-venting Cd being transferred from leaves to rice grains at the filling stage. SA spraying also decreased Cd toxicity by reducing H2O2 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.