Abstract: Endophytes and host plants have a mutual feedback and symbiotic relationship. Endophytes not only play multiple biological functions individually or cooperatively during seed germination, but also participate in the growth of host plants. Endophytes can transmit beneficial ones via vertical transmission when adapting to the symbiotic environment of host plants. This review focused on seed endophytes, and summarized research progress in the aspects of plant hormones synthesis, siderophore formation, phosphate salts dissolving, ACC deaminase production, nitrogen fixation, plant pathogen antagonization, secondary metabolites synthesis, and reactive oxygen species production. Moreover, this review proposed the possible mechanism of mutual benefits between seed endophytes and plants, and pointed out future research directions on the plant-endophyte interaction mechanisms.

Key words: seed, endophyte, growth promotion, pathogen inhibition, symbiotic relationship