Nitric oxide‐mediated regulation of oxidative stress in plants under metal stress: a review on molecular and biochemical aspects

Abstract

Given their sessile nature, plants continuously face unfavorable conditions throughout their life cycle, including water scarcity, extreme temperatures and soil pollution. Among all, metal(loid)s are one of the main classes of contaminants worldwide, posing a serious threat to plant growth and development. When in excess, metals which include both essential and non‐essential elements, quickly become phytotoxic, inducing the occurrence of oxidative stress. In this way, in order to ensure food production and safety, attempts to enhance plant tolerance to metal(loid)s are urgently needed. Nitric oxide (NO) is recognized as a signaling molecule, highly involved in multiple physiological events, like the response of plants to abiotic stress. Thus, substantial efforts have been made to assess NO potential in alleviating metal‐induced oxidative stress in plants. In this review, an updated overview of NO‐mediated protection against metal toxicity is provided. After carefully reviewing NO biosynthetic pathways, focus was given to the interaction between NO and the redox homeostasis followed by photosynthetic performance of plants under metal excess.

Phytohormones Regulate Accumulation of Osmolytes Under Abiotic Stress

“…Phytohormones play an important role in various biochemical and physiological mechanisms in plants. Their role in alleviating abiotic stress is critical in providing tolerance to plants under adverse condition [5,9,10,11,23,24,25,26,27,28]. Since both osmolytes and plant hormones have been known to play major roles during challenging environments, it is therefore imperative to correlate both and to further elucidate the role of phytohormones in the regulation of osmolytes under abiotic stress.…”

Involvement of nitrate reductase‐dependent nitric oxide production in magnetopriming‐induced salt tolerance in soybean

“…Nitric oxide (NO) is a bioactive and gaseous molecule that is repeatedly identified as an important signal in seed germination process, growth, development, resistance to plant disease and responses against abiotic stresses like drought, heavy metal and salt (Asai et al , Tripathi et al , b, Ahmad et al , Arif et al , Nabi et al , Prakash et al , Sharma et al ). In several crop seeds, NO was also found to proficiently break the dormancy and increase seed germination (Bethke et al , Sarath et al , Sarath et al , Li et al ).…”

Modulation of the Functional Components of Growth, Photosynthesis, and Anti-Oxidant Stress Markers in Cadmium Exposed Brassica juncea L.

“…Any major deviation from these required optimum conditions affects the plants adversely and may lead to death of the plants. The damage to plants results in retardation of growth, fresh weight, and food production [1,2,3,4,5,6,7,8,9,10]. Heavy metals are one of the major environmental toxicants.…”

“…The toxicity of these metals to plants depends upon the oxidation states [14]. The metal toxicity at cellular and molecular level changes various vital activities of plants, which includes deactivation and degradation of enzymes, proteins, displacement/substitution of important metal ions, blocking of functional groups of metabolically important molecules, structural changes, and membrane destabilization [5,14,15,16,17,18]. As a consequence, change in plant metabolism, decrease in respiration, photosynthesis, and change in enzyme activities is observed.…”