Bioprospecting Endophytes for Plant Growth Promotion

The plant–microbe interaction is a well-known relationship that is observed in the soil rhizosphere. Various microorganisms can colonize the interior parts of plants and establish a synergistic relationship. Several studies have described the bioprospecting abilities of these endophytes to facilitate increased growth and development of important agricultural crops. Hence, this chapter provides a description of the plant growth-promoting potential of these endophytes. Various endophytic bacterial species such as Bacillus cereus, Bacillus amyloliquefaciens, Bacillus pumilus, Bacillus megaterium, Bacillus thuringiensis, Bacillus zhangzhouensis, Brevibacillus agri, Paenibacillus barengoltzii, Pseudomonas mosselii, Serratia marcescens, Stenotrophomonas maltophilia, and others were isolated from plants such as Achillea fragrantissima, Fagonia mollis, Triticum aestivum L, etc., demonstrated significant plant growth-promoting abilities. Likewise, several fungal species such as Alternaria tenuissima, Aspergillus fumigates, Fusarium proliferatum, Fusarium solani, Fusarium tricinctum, Pseudochaetosphaeronema sp., and Paraconiothyrium hawaiiense were also isolated from different plants like Dendrobium loddigesii, Oxalis corniculata, Vanda cristata, and others for bioprospecting them towards alleviating plant stresses. These endophytes have shown various mechanisms such as the facilitation of nitrogen fixation, production of phytohormones, antibacterial or antifungal compounds, and induction of systemic acquired host resistance, which confers the stimulation of plant growth along with improved resistance against biotic and abiotic stresses. Therefore, further investigation of the long-term environmental impacts of bioprospecting by these endophytes for plant growth promotion can largely contribute in agricultural productivity and crop yield.