Previous studies have clearly demonstrated that the putative phytohormone melatonin functions directly in many aspects of plant growth and development. In Arabidopsis (Arabidopsis thaliana), the role of melatonin in seed oil and anthocyanin accumulation, and corresponding underlying mechanisms, remain unclear. Here, we found that serotonin N-acetyltransferase1 (SNAT1) and caffeic acid O-methyltransferase (COMT) genes were ubiquitously and highly expressed and essential for melatonin biosynthesis in Arabidopsis developing seeds. We demonstrated that blocking endogenous melatonin biosynthesis by knocking out SNAT1 and/or COMT significantly increased oil and anthocyanin content of mature seeds. In contrast, enhancement of melatonin signaling by exogenous application of melatonin led to a significant decrease in levels of seed oil and anthocyanins. Further gene expression analysis through RNA sequencing and reverse-transcription quantitative PCR demonstrated that the expression of a series of important genes involved in fatty acid and anthocyanin accumulation was significantly altered in snat1-1 comt-1 developing seeds during seed maturation. We also discovered that SNAT1 and COMT significantly regulated the accumulation of both mucilage and proanthocyanidins in mature seeds. These results not only help us understand the function of melatonin and provide valuable insights into the complicated regulatory network controlling oil and anthocyanin accumulation in seeds, but also divulge promising gene targets for improvement of both oil and flavonoids in seeds of oil-producing crops and plants.

先前的研究清楚地表明，假定的植物激素褪黑激素直接在植物生长和发育的许多方面起作用。在拟南芥（Arabidopsis thaliana）中，褪黑激素在种子油和花色苷积累中的作用以及相应的潜在机制尚不清楚。在这里，我们发现5-羟色胺N-乙酰基转移酶1（SNAT1）和咖啡酸O-甲基转移酶（COMT）基因普遍存在且高度表达，对于拟南芥发育中的种子褪黑素生物合成至关重要。我们证明了通过敲除SNAT1和/或COMT来阻止内源性褪黑素的生物合成显着增加了成熟种子的油和花青素含量。相反，通过外源施用褪黑激素增强褪黑激素信号转导导致种子油和花色苷水平显着降低。通过RNA测序和反转录定量PCR证实了一系列参与脂肪酸和花色素苷积累的重要基因的表达改变显著在进一步的基因表达分析snat1 - 1个COMT - 1在种子成熟过程中发育种子。我们还发现SNAT1和COMT显着调节成熟种子中黏液和原花青素的积累。这些结果不仅有助于我们了解褪黑素的功能，并为控制种子中油和花青素积累的复杂调控网络提供有价值的见解，而且还揭示了改善油料作物和植物种子中油和黄酮类化合物的有前景的基因靶标。 。