An insight into conflict and collaboration between plants and microorganisms

Plants and microorganisms have been co-evolving and interacting for billions of years. Prior researchers have explored the plant’s immune system responses and interaction with diverse microbes, but several ambiguities need further explanation. This review provides insight into mechanisms underlying plant–microbe interaction and knowledge dearth domains, along with possibilities to use beneficial microbes to improve plant growth, disease resistance, nutritional value, and productivity. Microorganisms in the phyllosphere and the rhizosphere could be beneficial or pathogenic. Host plants use their innate immune system and the antagonistic competence of plant-growth-promoting microbes against pathogens. The innate immune system of plants has two paramount protection forms involving different types of immune receptors, which assist in recognizing non-self-components. The first group of receptors is membrane-resident pattern recognition receptors (PRRs), which are responsible for sensing microbe-associated molecular patterns (MAMPs) and damage-associated molecular patterns (DAMPs). The second group consists of intracellular immune sensors, specifically resistance (R) proteins, astute in recognizing the structure or function of strain-specific pathogen effectors injected into host plant cells. Plants activate their pattern-triggered immunity (PTI) and effector-triggered immunity (ETI) defense mechanisms to counter the infection. Plants benefit from certain microbes by promoting their growth, disease resistance, and resilience under various stress conditions in exchange for shelter and nutrients. Graphical Abstract