Modulation of the ROS‐scavenging system in salt‐stressed wheat plants inoculated with arbuscular mycorrhizal fungi

Abstract

AbstractAlthough there is evidence for a positive involvement of the antioxidant defense system in plant response to salt stress, there is poor information regarding the influence of mycorrhizal symbiosis on enzymatic and nonenzymatic antioxidant defense in wheat under saline conditions. The present article focuses on the contribution of mycorrhizae to antioxidant defense in salt‐stressed wheat plants. Two wheat (Triticum aestivum L.) cultivars, Sids 1 and Giza 168, were grown under nonsaline or two saline conditions (4.7 and 9.4 dS m–1) with and without arbuscular mycorrhizal fungi (AMF) inoculation. Salt stress considerably decreased root colonization and plant productivity, particularly in Giza 168. Interestingly, mycorrhizal colonization alleviated the adverse effect of salt stress and significantly enhanced plant productivity, especially in Sids 1. The concentration of glycinebetaine, the activities of antioxidative enzymes (superoxide dismutase, peroxidase, catalase, and glutathione reductase) and the concentrations of antioxidant molecules (glutathione and ascorbate) were increased under saline conditions; these increases were more significant in salt‐stressed mycorrhizal plants, especially in Sids 1. Salt stress induced oxidative damage through increased lipid peroxidation, electrolyte leakage, and hydrogen peroxide concentration, particularly in Giza 168. Mycorrhizal colonization altered plant physiology and significantly reduced oxidative damage. Elimination of reactive oxygen species (ROS) can be one of the mechanisms how AMF improve wheat adaptation to saline soils and increase its productivity.