Abstract
Plant-associated microorganisms that live symbiotically in the plant body without causing disease symptoms are called endophytic microorganisms. Endophytes, including bacteria and fungi, can enhance the growth of the host plant and increase its resistance to pests, phytopathogens, and environmental stresses. In addition, endophytes can regulate the synthesis of plant secondary metabolites. Endophytes are a new reservoir for the discovery and production of valuable active substances. Some endophytic secondary metabolites are the same as host plants, such as paclitaxel. This finding has increased the importance of endophytes because the production of effective substances on an industrial scale in microorganisms is easier than in plants and has lower environmental costs. Therefore, endophytes need more attention in the pharmaceutical industry.