Abstract
Present work was carried out to investigate the possible role of arbuscular mycorrhizal fungi (AMF) in mitigating salinity-induced alterations in Brassica juncea L. Exposure to NaCI stress altered the morphological, physio-biochemical attributes, antioxidant activity, secondary metabolites and phytohormones in the mustard seedlings. The growth and biomass yield, leaf water content, and total chlorophyll content were decreased with NaCI stress. However, AMF-inoculated plants exhibited enhanced shoot and root length, elevated relative water content, enhanced chlorophyll content, and ultimately biomass yield. Lipid peroxidation and proline content were increased by 54.53 and 63.47%, respectively with 200 mM NaCI concentration. Further increase in proline content and decrease in lipid peroxidation was observed in NaCI-treated plants inoculated with AMF. The antioxidants, superoxide dismutase, ascorbate peroxidase, glutathione reductase, and reduced glutathione were increased by 48.35, 54.86, 43.85, and 44.44%, respectively, with 200 mM NaCI concentration. Further increase in these antioxidants has been observed in AMF-colonized plants indicating the alleviating role of AMF to salinity stress through antioxidant modulation. The total phenol, flavonoids, and phytohormones increase with NaCI treatment. However, NaCI-treated plants colonized with AMF showed further increase in the above parameters except ABA, which was reduced with NaCI+AMF treatment over the plants treated with NaCI alone. Our results demonstrated that NaCI caused negative effect on a juncea seedlings; however, colonization with AMF enhances the NaCI tolerance by reforming the physic biochemical attributes, activities of antioxidant enzymes, and production of secondary metabolites and phytohormones.