紫花苜蓿甘氨酸脱羧酶H-蛋白基因MsGDC-H1功能分析  

Functional analysis of glycine decarboxylase H-protein gene MsGDC-H1 in Medicago sativa

作　　者：尉春雪 何飞 许蕾 李霄 张立霞 李明娜[1] 陈林 康俊梅[1] 杨青川[1] 龙瑞才[1] WEI Chun-xue;HE Fei;XU Lei;LI Xiao;ZHANG Li-xia;LI Ming-na;CHEN Lin;KANG Jun-mei;YANG Qing-chuan;LONG Rui-cai(Institute of Animal Sciences,Chinese Academy of Agricultural Sciences,Beijing 100193,China)

机构地区：[1]中国农业科学院北京畜牧兽医研究所,北京100193

出　　处：《草业学报》2022年第12期95-105,共11页Acta Prataculturae Sinica

基　　金：内蒙古自治区科技重大专项(2021ZD0031);国家现代农业产业技术体系项目(CARS-34)资助。

摘　　要：光呼吸通过清除2-磷酸乙醇酸(2-PG)使氧合光合作用成为可能,该过程对C3植物至关重要。H-蛋白是光呼吸过程中将甘氨酸转化为丝氨酸的甘氨酸脱羧酶(GDC)的关键组成蛋白之一。本研究克隆了紫花苜蓿MsGDCH1,该基因编码166个氨基酸,具有1个硫辛酰基附着位点保守结构域和1个N6-硫辛酰赖氨酸保守位点。进化分析表明,MsGDC-H1蛋白与双子叶植物的甘氨酸脱羧酶H-蛋白(GDC-H)亲缘关系近。表达模式分析表明,MsGDC-H1在苜蓿叶中表达丰度高,且受光诱导。为了探究MsGDC-H1基因对拟南芥生长的影响,分别使用光诱导的茎叶特异性启动子ST-LS1和组成型启动子CaMV 35S驱动MsGDC-H1(ST-LS1::MsGDC-H1;CaMV35S::MsGDC-H1)在拟南芥中异源表达。检测过表达植株生物量、淀粉、可溶性糖含量以及光合速率。数据分析显示,CaMV 35S::MsGDC-H1过表达拟南芥(G系列植株)生长受阻,淀粉含量比ST-LS1::MsGDC-H1特异性表达拟南芥(GS系列植株)增加了34%~67%,比野生型(WT)增加了7。3%~33。7%;可溶性糖含量比GS系列降低了36%~38%,比WT增加了44。3%~49。7%;与WT相比,GS系列植株生长更快,淀粉含量无显著差异(P>0。05),可溶性糖含量显著增加(P<0。05)。试验结果表明,MsGDC-H1基因在调控拟南芥光合速率、碳水化合物合成以及生长等方面发挥重要作用,未来可作为提高苜蓿产量的基因工程育种候选基因。Photorespiration is essential for C3plants,allowing oxygenated photosynthesis by removing 2-phosphoglycolate.H-protein is one of the key components of glycine decarboxylase(GDC),which converts glycine to serine during photorespiration.The MsGDC-H1 gene was cloned from Medicago sativa.The cloned gene encoded 166 amino acids and had a conserved lipoyl-binding domain and a conserved N6-lipoyllysine site.Phylogenetic analysis showed that MsGDC-H1 was closely related to glycine decarboxylase H-protein(GDC-H)in other dicotyledons.The expression pattern analysis showed that MsGDC-H1 was highly expressed in leaves and was induced by light.To explore the effects of MsGDC-H1 on Arabidopsis thaliana growth,photoinduced stem-leaf specific promoter ST-LS1 and constitutive promoter CaMV 35S were used to drive MsGDC-H1 expression(STLS1::MsGDC-H1;CaMV 35S::MsGDC-H1).MsGDC-H1 is heterogeneously expressed in A.thaliana.Biomass,starch and soluble sugar content and photosynthetic rate of overexpressed plants were evaluated.Data analysis showed that CaMV 35S::MsGDC-H1 overexpression(G series)inhibited A.thaliana growth.The starch content of G series was increased by 34%-67%compared with A.thaliana in which ST-LS1::MsGDC-H1 was overexpressed(GS series),and was increased by 7.3%-33.7%compared with wild type(WT)A.thaliana;The soluble sugar content was decreased by 36%-38%compared with GS series and increased by 44.3%-49.7%compared with WT A.thaliana.Compared with WT,GS series plants grew faster,starch content was not significantly different(P>0.05),and soluble sugar content was significantly increased(P<0.05).The experiment results show that MsGDC-H1 plays an important role in regulating photosynthetic rate,carbohydrate synthesis and growth of A.thaliana,and can be used as a candidate gene in genetic engineering breeding to improve alfalfa yield in the future.

关 键 词：甘氨酸脱羧酶H-蛋白 产量 光合速率 糖含量 拟南芥 

分 类 号：S541.9[农业科学—作物学]