Contamination of heavy metal in soil causes several severe environmental problems. Cadmium is one of the most toxic metals to organisms. In plants, Cd toxicity often results in over-accumulation of reactive oxygen species (ROS), which causes oxidative damage to the plant organs. In this review, we discussed the processes of how Cd stress causes over-accumulation of ROS in plant and how plant recovers from the Cd-induced oxdative stress. We especially focused on the roles of signal, including nitric oxide (NO), calcium (Ca), plant hormones (e.g. auxin and abscisic acid) and mitogen-activated protein kinases (MAPKs), in above two processes. Our review may provide theoretical basis for future research on the mechanism of plant tolerating Cd stress.
土壤重金属污染引发了一系列严峻的环境问题.其中,镉(Cd)是生物毒性最强的重金属元素之一.活性氧(ROS)过量积累引起的氧化胁迫,是Cd毒害植物的主要原因之一.本文围绕Cd胁迫引起的ROS积累及清除过程,重点阐述介导上述过程的一些信号调控物质包括一氧化氮(NO)、钙(Ca)、植物激素如生长素(IAA)和脱落酸(ABA)等及有丝分裂原活化蛋白激酶(MAPKs)的变化及其在缓解Cd诱导的氧化胁迫中的作用,以期为今后植物抗Cd胁迫生理生化机制的研究提供一定的理论依据.
Keywords: Ca; NO; ROS; cadmium stress; plant hormone.