Research On The Mechanism Of Melatonin Affecting Seed Germination

Seed germination is an important developmental stage in the life cycle of seed plants that regulated by complex signals.Melatonin is a small molecule thought to be associated with seed germination.In this study,we found that melatonin regulated seed germination had significant dose-effect.Low concentrations of melatonin(10μM)promote seed germination,while high concentrations of melatonin(500μM and 1000μM)inhibit seed germination.After high-concentration melatonin treatment of seeds,RNA-Seq was used to explore germination-related candidate genes.It was found that melatonin regulates seed germination mainly by regulating sugar metabolism and the related synthesis,metabolism and repair processes of cell.In addition,melatonin also inhibits the synthesis,transport and response gen of auxin.The Arabidopsis seeds were co-treated by exogenous addition of melatonin and other plant hormones.When Arabidopsis seeds were treated by auxin and melatonin together,auxin could alleviate the inhibition of high concentration of melatonin on seed germination.This result indicating that there would exist a cross-talk regulation process,which:in turn affects plant seed germination.The germination experiment was carried out by constructing overexpression plants and T-DNA insertion mutants of melatonin synthase genes serotonin N-acetyltransferase(SNAT)and N-acetyl serotonin methyltransferase(AMST).It was shown that the seed germination were delayed in the overexpressed plants,and advanced in the mutants,further confirming that melatonin plays a role in seed germination.This research provides new light and directions for exploring the regulation mechanism of seed germination from the perspective of melatonin,and discovers new possibilities for studying the cross-talk between hormones and auxins.