Mechanisms and Strategies of Plant Microbiome Interactions to Mitigate Abiotic Stresses

Abiotic stresses are the most significant factors reducing agricultural productivity. Plants face extreme environmental conditions that may affect their biological mechanisms, thereby influencing their growth and development. Microorganisms possess substantial metabolites that aid in helping plants mitigate abiotic stresses. Plants’ interaction with microbes constitutes a diversified ecosystem, as sometimes both the partners share a mutualistic relationship. Endophytes, plant-growth-promoting rhizobacteria (PGPRs), and arbuscular mycorrhizal fungi (AMFs) are examples of microorganisms that play an essential role in alleviating abiotic stresses and, hence, improving plant growth. The plant–microbe interaction leads to the modulation of complex mechanisms in the plant cellular system. Moreover, the residing microbial flora also inhibits the phytopathogens, therefore, it becomes part of plants’ innate defense system. Keeping in view the growing environmental concerns, it is important to identify the role of the plant microbiome in the transportation of nutrients to maintain sustainable production. Furthermore, it is important to identify the factors enabling plants to recruit beneficial microbial species and how to deal with the potential pathogens. Therefore, this review aims to summarize the impacts of various abiotic stressors on agricultural productivity and the role of beneficial microorganisms in mitigating the negative effects of abiotic stresses. The literature review also shows that the beneficial microbes, including PGPRs, AMFs, and endophytes, adopt various mechanisms for ameliorating the negative effects of various stresses. It has been observed that biochar and microbes, either individually or in combination, can play a significant role in maintaining plant growth under stress conditions. Although conventional inoculation of beneficial microbes mitigates abiotic stresses and enhances productivity, the advancement in genetic engineering would help transfer specific genes from the microbes to plants to aid in abiotic stress mitigation.