关键词: 叶酸, 5甲酰四氢叶酸, 低氮, 氮代谢, 水稻

Abstract: Folates, also known as vitamin B9, are essential cofacotors for growth and development of almost all organisms. Previously, it was found that the nitrogen metabolism was disturbed in Arabidopsis folatedefect mutants. However, the molecular mechanisms remain completely unknown. This study used rice (Oryza sativa L. Japonica) as material and explored the effect of 5formyltetrahydrofolate supplement on rice seedling growth and nitrogen metabolism under different nitrogen conditions and the molecular mechanism. The results showed as follows: under low nitrogen conditions, a slow growth and decrease in shoot length, fresh weight and chlorophyll content were observed in rice seedlings; exogenous 5formyltetrahydrofolate (200 μmol·L-1) could significantly promote the growth of rice seedlings and increase the shoot length, fresh weight and chlorophyll content under low nitrogen conditions; the content of folate derivatives, soluble protein, free amino acid were elevated with the addition of 5formyltetrahydrofolate; further analysis revealed that the enzymatic activity and gene transcription level of glutamate synthase were significantly increased. It predicted that folates could be involved in rice nitrogen metabolism by regulating the transcription and activity of glutamate synthase. These results were helpful for understanding the molecular mechanism underlying folates’ participation in plant nitrogen metabolism and provided new clues for the alleviation of lownitrogen stress and to increase plant nitrogen use efficiency.

Key words: folates, 5FTHF, low nitrogen, nitrogen metabolism, rice