Inoculation of Rhizobium Alleviates Salinity Stress Through Modulation of Growth Characteristics, Physiological and Biochemical Attributes, Stomatal Activities and Antioxidant Defence in Cicer arietinum L.

Abstract

Rhizobium is a plant growth-promoting bacteria, generally involved in nitrogen fixation and promotes growth in plants under abiotic-stressed conditions such as salinity. The present study investigates the significance of Rhizobium application in alleviation of salt stress in chickpea by increasing cell viability, stomatal movement, photosynthetic pigment and protein content, nitrate reductase, carbonic anhydrase as well as enzymatic and non-enzymatic antioxidant activities. Healthy and viable seeds were inoculated with Rhizobium before sowing. Salt treatment was given in terms of NaCl (50 or 150 mM) to the plants through soil at 20 days after sowing. High NaCl level (150 mM) reduced the growth attributes, pigment as well as soluble protein content, altered stomatal behaviour, reduced cell viability and enhanced the formation of superoxide radicals and other reactive oxygen species in foliage. Moreover, Rhizobium inoculation improved the mineral uptake, reduced electrolyte leakage which directly influences photosynthesis and improved yield attributes in the salt-treated chickpea plants. Therefore, Rhizobium could be applied to chickpea plants for efficient growth under salt stress.