5-甲酰四氢叶酸促进水稻幼苗在低氮条件下生长发育的研究  

Exogenous 5-Formyltetrahydrofolate Improves Rice Seedlings Growth Under Limiting Nitrogen Condition

作　　者：易尘 张春义[1] 梁秋菊[1] YI Chen;ZHANG Chunyi;LIANG Qiuju(Biotechnology Research Institute,Chinese Academy of Agricultural Sciences,Beijing 100081,China)

机构地区：[1]中国农业科学院生物技术研究所,北京100081

出　　处：《中国农业科技导报》2020年第4期33-43,共11页Journal of Agricultural Science and Technology

基　　金：国家转基因生物新品种培育重大专项(2016ZX08003-002)。

摘　　要：叶酸又称为维生素B9,是生物体生长发育的重要辅因子。前期研究发现拟南芥叶酸代谢突变体的氮代谢也出现异常,但目前叶酸代谢影响植物氮代谢的分子机制还不是很清晰。以水稻日本晴为材料,分析不同氮浓度条件下施加5-甲酰四氢叶酸对水稻幼苗生长发育、氮代谢的影响及分子机制。结果表明:在低氮条件下,水稻幼苗的叶片发育缓慢,叶绿素含量、株高、鲜重均显著降低;在水稻幼苗根部施加5-甲酰四氢叶酸(200μmol·L^-1)能够显著促进幼苗在低氮条件下的生长发育,株高、鲜重、叶绿素含量均有提高,叶酸衍生物含量、可溶性蛋白含量、游离氨基酸含量均显著提高;5-甲酰四氢叶酸处理后,幼苗体内的谷氨酸合酶活性增加、谷氨酸合酶基因的转录水平上调,推测叶酸可能通过促进水稻谷氨酸合酶基因表达、酶活性进而影响氮代谢。这些结果为理解叶酸代谢与植物氮代谢的作用关系奠定基础,为农业生产中缓解低氮胁迫、提高植物氮素利用效率提供新思路。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.

关 键 词：叶酸 5-甲酰四氢叶酸 低氮 氮代谢 水稻 

分 类 号：S511[农业科学—作物学]