Bacterial Endophytes: A Versatile Factory for Producing Indole-3-acetic Acid, Recent Advances and Development

The growing scientific interest and exploration of endophytes from plants have shown vital plant health promotion, and are attracting scientific interest. The endophytes, including bacteria, significantly strengthen the host plants' growth and resilience, fortifying the plants’ ability to combat pathogens and adapt to environmental stresses. Previous studies have investigated the pivotal role of endophytic bacteria in modulating the synthesis of secondary metabolites with medicinal properties and diverse biological effects. Endophytic bacteria are well-known sources of metabolites with notable medicinal potential and ability to boost plant growth, fortifying invulnerability to abiotic stress and biotic stress on plants. The catalog of primary and secondary metabolites that are produced by different endophytes indole-3-acetic acid (IAA) is an eminent constituent of the auxin in the indole derivatives family. IAA governs nearly every facet of botanical growth and progression, making it among the most significant phytohormones for plants. Notably, the endophyte bacteria deliver IAA which holds significance in growth and progression interactions with plants. Delving into the mechanisms underlying the biological synthesis and functions of IAA in endophytic bacteria can boost the production and application of IAA in agriculture and allied sectors. This review unifies recent research advancements in the production of IAA from bacterial endophytes and explains the pathway analysis for the biological synthesis of IAA.