Bioefficacy of Endophytes in the Control of Plant Diseases

Plants establish multiple kinds of interactions with microorganisms, which can be neutral, beneficial, or detrimental for the plant host. Interactions also occur between endophytic microorganisms that colonize inner parts of plants, beneficial in nature, and able to promote plant growth both directly or indirectly. Direct plant-growth promotion includes the production of phytohormones, nitrogen fixation, and an increase in nutrient availability. On the other hand, endophytes can promote plant growth indirectly by contributing some beneficial attributes to plant health. Direct interaction between pathogens and endophytes also induces systemic resistance in the host, which allows the plant to respond faster and/or more intensively upon pathogen infection. Usually, endophytes share more than one of these mechanisms so the outcome of the interaction is the sum of different strategies. In this chapter, review on bacterial and fungal endophytes as potential biological control agents and their mechanisms of action have been documented. Besides it analyzes the most recent information about the nutrient uptake/management, specifically iron and nitrogen nutrition, with the biological control exerted by beneficial microorganisms.