Physiological responses of crop plants against Trichoderma harzianum in saline environment

Abstract

The physiological response of crop plants against Trichoderma harzianum (Th-6) in a saline habitat was studied. Trichoderma harzianum (Th-6) is an endophytic fungus that shows salt tolerance and establishes a symbiotic relationship with a host plant. To evaluate the role of Trichoderma harzianum (Th-6) in mitigating the consequences of salinity stress on crop plants, seeds of maize and rice were coated with Trichoderma before sowing and salt treatment. Later, after germination, twenty-one day old seedlings were subjected to NaCl concentrations (50, 100 and 150 mM). Salinity negatively affected all investigated physiological parameters in both crops. Treatment of seeds with Trichoderma improved plant growth and Th-treated plants exhibited substantial physiological adjustment in a saline environment compared to Th-untreated plants. The Th-treated plants under salt stress showed higher relative water content and stomatal conductance, better photosynthetic performance and higher pigment concentrations, as well as higher catalase and superoxide dismutase activities. Moreover, proline content in salt stress environment was higher in Th-treated plants, while H2O2 content declined. The physiological role of Trichoderma harzianum in mitigating the salt related consequences of both crop plants is discussed.