SELENIUM NANOPARTICLE PROTECTED STRAWBERRY AGAINST SALT STRESS THROUGH MODIFICATIONS IN SALICYLIC ACID, ION HOMEOSTASIS, ANTIOXIDANT MACHINERY, AND PHOTOSYNTHESIS PERFORMANCE

摘要

Since plant responses to selenium nanoparticles (nSe) had not been clarified, this study was carried out to evaluate the effects of nSe (10 and 100 mu M) on photosynthesis performance, ion homeostasis, antioxidant system, and phenylpropanoids in strawberry exposed to salt stress. Inductively Coupled Plasma-Mass Spectroscopy analyses indicated that foliar-applied nSe can be taken up by leaves and trans-located to roots. Salinity led to an increase in Na concentration and reductions in Ca and K contents which were relieved by the nSe applications. Moreover, the nSe treatment at 10 mu M alleviated the NaCl-induced lesion to PSII functioning, contributing to improvement in water-splitting complex (F-v/F-o) under salinity. The exposure to nSe at a concentration of 100 mu M exhibited a moderate stress, determined by the increases in hydrogen peroxide (H2O2) and lipid peroxidation rate (membrane integrity index). The nSe10 treatment increased catalase activity and phenylpropanoid derivatives contents (salicylic acid, catechin, and caffeic acid) and decreased the content of oxidants under salinity condition. Consequently, nSe utilization at a suitable dose can be an effective method to alleviate signs of salt stress via improvements in photosynthesis, ion hemostasis, photosynthesis performance, salicylic acid (a vital signaling defensive hormone), and antioxidant machinery.