Endophytic bacteria: A biotechnological potential in agrobiology system

Abstract

Endophytes are microorganisms that inhabit the interior of plant tissues without causing harm to the host. This definition includes internal colonists with apparently neutral behavior as well as symbionts. It also includes bacteria that migrate back and forth between the surface and the inside of the plant during their endophytic phase. The utilization of endophytic bacteria for biotechnological purposes has increased recently, especially in pest and disease control and in plant growth promotion. Endophytic bacteria promote plant growth function in three different ways: they synthesize particular compounds for the plants, facilitate the uptake of certain nutrients from the soil, and control or prevent diseases (biological control). Growth promotion mediated by endophytic bacteria includes several mechanisms: the production of vital enzymes; the production of hormones such as auxin (indole acetic acid [IAA]); symbiotic nitrogen fixation; antagonism against phytopathogens caused by the production of siderophores, chitinases, or antibiotics; and the solubilization and mineralization of nutrients, particularly mineral phosphates. Exploitation of the interactions between endophytes and plants can promote plant health and play a significant role in low-input sustainable agriculture for both food and nonfood crops. An understanding of the mechanisms enabling these endophytic bacteria to interact with plants is essential to achieve the biotechnological potential of these microorganisms.