An overview of the roles of critical insiders and outsiders for reciprocal plant–microbe interaction: Heterotrimeric G-proteins, small RNAs, pollinators, microalgae

Plants are exposed to various abiotic stresses, which lead to crop losses and become a significant threat to agriculture worldwide. To survive, they have developed a range of mechanisms throughout their life cycle. While they develop immunity against stressors through their metabolic and hormonal pathways, as another strategy, they can also modify their environment by interacting with symbiotic microorganisms involved in the critical pathways for plant health. Several beneficial microorganisms can be used as plant stimulants to augment plant health and growth. Therefore, elucidating the cause-effect relationship and possible roles of critical players during plant–microbe interaction may help us better understand the usage of microorganisms for plant benefits. The presented review discusses the molecular mechanisms regulating the responses of plants and their environment during plant–microbe interactions. We focus on the potential roles of plant heterotrimeric G-proteins and small RNAs as inside players and the possible roles, connections, and effects of microalgae and pollinators as outside players/elements during plant–microbe interactions under abiotic stress. Utilizing microbial inoculants with a better combination of endophytes based on various plant species/populations under different environmental conditions is critical for successful field applications. The current knowledge in this review may provide a detailed assessment to gain insight into unraveling different parameters for efficient use of the endophytes on plants/crops to address food security challenges and mitigate the impact of climate change on agriculture.