The effects of some Trichoderma spp. strains in maize (Zea mays L.) plants under salt stress

The effects of the Trichoderma atroviride ID20G, Trichoderma harzianum ID11C and ID11D strains on salt stress were investigated in maize plants (Zea mays L. cv Samada 07) in the present study. After pre-treatment of maize seeds with fungal strains, differences in root and shoot growth parameters were recorded in 50 mM and 100 mM NaCl treated plants. Moreover, Relative water content, lipid peroxidation, prolin, soluble proteins, photosynthetic pigment amounts, antioxidant enzyme activities such as superoxide dismutase (SOD), guaiacol peroxidase (GPX), glutathione reductase (GR) and catalase (CAT) maximum quantum yield of PSII photochemistry (Fv/Fm),the effective quantum yield of (QPS2), electron transfer rate (ETR), non-photochemical quenching (NPQ) and photochemical quenching(qP) values were measured in roots and shoots. Pre-treatment of Trichoderma strains significantly rescued the adverse effects of salt stress in relative water (RWC) content, total carotenoid and chlorophyll contents. While lipid peroxidation, soluble protein and prolin contents were increased in maize seedlings under salt stress, fungal treatment significantly decreased the lipid peroxidation in roots and shoots. The increment was much more in soluble protein and prolin contents in Trichoderma treated maize seedlings. The activity of SOD, GPX, GR and CAT were increased with salt stress. Variations were obtained regarding enzyme activities in maize plants, depends on the effect of pre-treated fungal strains and applied salt concentration. While salt stress caused reduction in Fv/Fm, QPS2, ETR and qP, NPQ was enhanced in maize seedlings under salt stress. Fv/Fm, QPS2, ETO and qP values were recorded higher than that of salt stress treated only seedlings, as for NPQ values were decrased in of Trichoderma and salt treated plants.These results show that these fungal strains have capability to increase photosynthetic efficiency in maize plants under salt stress. In addition, related strains significantly rescued the adverse effects of salt stress and T. atroviride ID20G was determined the most effective strain among all strains.