过表达叶酰聚谷氨酸合成酶对低氮胁迫下叶酸突变体的影响

Effects of the Overexpression of Folylpolyglutamate Synthase to Folate Mutant Influences Responses in Low Nitrogen Stress

为了解低氮胁迫下质体定位的叶酰聚谷氨酸合成酶（DFB）对同工酶（DFC）功能缺失作用,通过在拟南芥dfc突变体中过表达DFB,分析低氮条件下过表达DFB拟南芥的主根长度、相关基因转录水平及叶酸含量的变化。结果显示：在低氮环境和dfc背景下,过表达DFB的拟南芥主根长恢复至野生型拟南芥的65%～131%,叶酸和氮代谢相关基因的RT-PCR电泳条带亮度与野生型拟南芥相似,5-甲酰四氢叶酸含量增加至野生型拟南芥的90%～116%。表明,在低氮胁迫条件下DFB在一定程度上能对DFC的缺失起到弥补作用。

To explore the folylpolyglutamate synthase DFB located in plastid for the loss of function of isozyme DFC under low nitrogen stress,DFB was overexpressed in dfc mutants,and the primary root length,transcriptional levels of related genes and folate content were analyzed in the DFB overexpressing Arabidopsis under low nitrogen.The overexpression of DFB in dfc mutants under low nitrogen resulted that the primary root length was recovered to 65%~131% of that in the wild-type Arabidopsis,the brightness of RT-PCR bands was similar between genes involved in folate and nitrogen metabolism and wild-type genes and 5-formyl-tetrahydrofolate content was increased to 90%~116% of that in the wild-type Arabidopsis.These results implied that DFB could compensate the lack of DFC under low nitrogen stress in some extent.