Bioinoculants as mitigators of multiplestresses: A ray of hope for agriculture in the darkness of climate change

Abstract

Plant encounters various biotic and abiotic stresses, that affect agricultural productivity and reduce farmer's income especially under changing global climate. These environmental stresses can advance plant senescence by inducing osmotic stress, nutrient stress, hormonal imbalance, production of oxygen radicals, and ion toxicity, etc. Additionally, these stresses are not limited to plant health but also deteriorate soil health by affecting the microbial diversity of soil. To tackle this global delinquent of agriculture, several methods are suggested to ameliorate the negative effect of different types of stresses, the application of beneficial microorganisms or bioinoculants is one of them. Beneficial microorganisms that are used as bioinoculants not only facilitate plant growth by fulfilling the nutrient requirements but also assist the plant to withstand these stresses. These microorganisms produce certain chemicals such as 1-aminocyclopropane-1-carboxylate (ACC) deaminase, phytohormones, antioxidants, extracellular polysaccharide (EPS), siderophores, antibiotics, and volatile organic compounds (VOCs), etc. which help the plants to mitigate various stresses. Besides, these microbes also activate plant defence responses. Thus, these bioinoculants can effectively replace chemical inputs to supplement nutrient requirements and mitigation of multiple stresses in plants.