Table 1.

Different types of interaction between plant and microbes.

S. No.	Types of Plant-Microbe Interaction	Description
i.	Plant growth-promoting microorganisms (PGPMs)	Microbes which benefit plants majorly through improved acquisition of nutrients by nitrogen fixation [26, 27], solubilizing inorganic phosphate [28, 29], organic phosphorous mineralization and production of siderophores for the uptake of iron [30]. Plant growth-promoting bacteria (PGPM) can enhance the accessibility of water and minerals by synthesizing growth regulators such as gibberellins [31] and auxin.
ii.	Plant disease suppression by rhizobacteria	Rhizobacteria can prevent plant diseases by producing incompatible compounds against phytopathogens (antibiotics competition, siderophores production) through priming. Priming helps in enhancing the defense system of the plants and inducing the resistance against pathogens. Various bacterial traits were discovered as triggers of induced systemic resistance [32] like cell envelope components, flagellae, phenolic compounds, antibiotics and quorum sensing.
iii.	Mycorrhizae	Arbuscular mycorrhizal fungi have the ability to spread the plant root systems and enhance the accessibility of the roots to nutrients with low mobility in plants. The roots of the plant are interconnected by hyphal networks of mycorrhizae. This network assists in resource exchange and also supplies about 90% of nitrogen [33].
iv.	Rhizobia	Nitrogen entry into soil can be identified by interactions between legume and rhizobium. Plants metabolize the ammonium that is produced by the reduction of nitrogenase from atmospheric dinitrogen by nitrogen-fixing bacteria.
v.	Plant-Pathogen Interaction	(a) Biotrophic Pathogens: This type of interaction requires living plant tissue. Fungal haustoria are invaginations in the cell membrane of the living host for the extraction of nutrients.
		(b) Necrotrophic Pathogens: Production of cellulolytic enzymes or toxins causes necrosis in the infected tissues taking up nutrients from the dead spots.
		(c) Hemibiotrophic pathogens: These pathogens include both the biotrophic and necrotrophic pathogens. An early biotrophic infection phase is followed by the necrotrophic spreading phase.