Melatonin reprograms soil microbial community, creates friendly soil environments, and promotes peanut growth

Melatonin coated crop seeds have been shown to promote plant growth and development, but the relationship between melatonin mediated plant-soil microorganisms and soil environment remains unclear. In this study, we analyzed the regulation effect of melatonin on the growth and development of peanut through seed coating and the internal factors of synergistic interaction between soil microbial flora and root exudates to create a favorable living environment for the growth and development of peanut. The results showed that melatonin could promote the growth of peanut by enhancing the photosynthetic efficiency of peanut. In addition, melatonin also mediated the changes of the root exudate components to recruiting the enrichment of beneficial bacteria and fungi in soil and increase their relative abundance. These bacteria and fungi produce secondary metabolites (such as chenodeoxycholic acid and capric acid) and combine with plant hormones (including jasmonic acid and salicylic acid) to resist pathogen invasion. Some bacteria (such as Gymnopus fungi) can also secrete secondary metabolites in response to changes in soil pH, creating a suitable environment for plants to grow. We provide a theoretical basis for its application in agriculture by studying the interaction between plant growth mediated by melatonin and soil microorganisms.