The role of priming with biosynthesized silver nanoparticles in the response of Triticum aestivum L. to salt stress

T HE PRESENT study investigated the synthesis of silver nanoparticles (AgNPs) using Capparis spinosa extract as reducing and stabilizing agent. The biosynthesized AgNPs were characterized by UV-vis spectrophotometer and energy dispersive spectroscopy (EDS) analysis. The shape and size of the biosynthesized AgNPs were studied using transmission electron microscope (TEM). The study also investigated whether the biosynthesized AgNPs (as a priming agent; 1 mg L-1) has a role in the alleviation of the salt-induced toxicity of germinating Triticum aestivum L. grains grown under salt stress (25 and 100 mM NaCl). Generally, AgNPs priming stimulate the germination and growth of wheat grains. In addition, it affects the plant phytohormones balance by stimulating indole-3-butyric acid (IBA), 1-naphthalene acetic acid (NAA), 6-benzylaminopurine (BAP) contents and reducing abscicic acid (ABA) content. Slat stress had an inhibitory effect on wheat seedling as evident by a significant decrease in GP, growth index, pigment contents and chlorophyll stability index (CSI), auxins and cytokinins contents and a marked increase in ABA content particularly at 100 mM NaCl. All these parameters were markedly improved by AgNPs priming notably growth parameters and photosynthetic efficiency as well phtyohormones balance suggesting that AgNPs priming might has a role in the improvement of plant tolerance against environmental stresses such as salinity.