Role of NO-Mediated H_2O_2 Signaling under Abiotic Stress (Heavy Metal)-Induced Oxidative Stress in Plants: An Overview

摘要

Environmental stress, like heavy metal, constitutes the most significant factor leading to a substantial and unpredictable decrease in crop yield in agriculture. Hydrogen peroxide (H_2O_2) and nitrogen oxide (NO) are produced as primary signals in a stress signal cascade. H_2O_2 accumulation can lead to either enhanced expression of antioxidant enzymes or increased expression of other defense proteins. Alternatively, it can initiate programmed cell death, particularly when NO is also produced, depending on the intensity of the oxidative signal or oxidative load exerted by heavy metal toxicity in tissues. In this review, we examine the regulatory role of H_2O_2 and NO signaling in oxidative stress induced by heavy metals in plants, exemplified by a number of research studies and show how this signaling in response to heavy metals may provide some clues to improving crop productivity.