Mangrove endophytes and their natural metabolites: role in promoting plant health

Mangroves are forests commonly found in tropical and subtropical countries at the interface between the aquatic and the terrestrial environment. In this unique environment, plants have adapted to thrive in extreme conditions such as high salinity, strong light intensity, regular tidal floodings, and low oxygen levels. Mangrove plants harbor a rich diversity of microbial symbionts, called endophytes, that produce a wide range of natural metabolites. Mangrove endophytes and their metabolites have been reported to enhance plant fitness by promoting growth and increasing resistance to abiotic and biotic stress. This chapter will focus on mangrove endophytes, the metabolites they produce, and their role in stimulating plant development and strengthening plant defenses against pathogens and pests. A special emphasis will be placed on Avicennia endophytes and their metabolites, as Avicennia has been described as the only mangrove genus occurring all over the world.