转玉米PEPC和PPDK基因杨树苗期的光合生理特性  

Photosynthetic Characteristics of Transgenic Poplars with Maize PEPC and PPDK Gene at Young Plant Stage

作　　者：孙伟博 宫新栋 周燕 李红岩 Sun Weibo;Gong Xindong;Zhou Yan;Li Hongyan(College of Biology and the Environment,Nanjing Forestry University,Nanjing 210037)

机构地区：[1]南京林业大学生物与环境学院,南京210037

出　　处：《林业科学》2020年第7期33-43,共11页Scientia Silvae Sinicae

基　　金：国家林业局林业科技发展项目(KJZXSA2018004);转基因生物新品种培育重大专项(2018ZX08020002)。

摘　　要：【目的】磷酸烯醇式丙酮酸羧化酶(PEPC)和磷酸丙酮酸二激酶(PPDK)是保证C4植物高效光合作用的关键酶。杨树作为光合效率较低的C3植物,其光能利用率低,本研究以玉米PEPC基因和PPDK基因分别作为目的基因进行杨树遗传转化,分别获得转基因的高效表达植株,并进行分子检测及相关功能分析,为培育杨树高光效新品种提供依据。【方法】通过生物信息学筛选玉米PEPC和PPDK基因。利用Gateway系统,将PEPC和PPDK基因分别构建到植物表达载体pGWB406,通过农杆菌介导法转化南林895杨。比较分析转基因植株与对照(南林895杨)的光合生理特性。【结果】筛选克隆的PEPC及PPDK基因均编码典型的C4光合作用关键酶。南林895杨转PEPC基因获得5个株系,不同株系间基因表达量具有差异,最大达1.79倍,但编码蛋白在不同株系叶片中的表达量无显著差异;转PPDK基因获得3个株系,各株系间基因及蛋白表达量无显著差异。PEPC和PPDK在叶片中的表达量均高于茎中,且随着植株生长发育而提高;PEPC和PPDK基因的表达均受光照条件的影响,在高光照下表达量上升2~3倍。转基因株系净光合速率在11:00—14:00出现双峰状态,且显著高于对照组,最高达16.2%(PEPC-5株系);气孔导度在12:00—16:00高于对照组;除PPDK-2株系外,转基因株系都检测到比对照组更高的胞间CO2浓度,除PEPC-1和PEPC-4株系外,转基因株系CO2饱和点均低于对照组;全部转基因株系CO2补偿点均低于对照组,且光饱和点以及在光饱和点的光合速率均高于对照组。生长参数方面,PEPC-3和PEPC-4株系多个指标显著优于对照组(P<0.05),平均株高分别高于对照组5.6%和2.9%,叶面积分别高于对照组13.8%和8.9%,叶片质量分别高于对照组23.6%和19.8%,地径分别高于对照组13.5%和5.4%;转基因株系的茎生物量均高于对照组,叶生物量优势最为明显的依次是PEPC-3、PEPC-5和PEPC-4株系,分别高于对�【Objective】Phosphoenol pyruvate carboxylase(PEPC)and phosphopyruvate dikinase(PPDK)are the key enzymes to ensure efficient photosynthesis in C4 plants.Poplar,as a C3 plant with low photosynthetic efficiency,has low light energy utilization.In this study,maize PEPC gene and PPDK gene were used as target genes for genetic transformation in poplar,respectively,to obtain highly expressed transgenic plants,and molecular detection and functional analysis were carried out to provide a basis for breeding new poplar varieties with high light efficiency.【Method】The PEPC and PPDK genes of maize were screened through bioinformatics.With Gateway system,PEPC and PPDK genes were constructed into plant expression vector pGWB406,respectively,and transformed into‘Nanlin 895’poplars(Populus deltoides×P.euramericana‘Nanlin 895’)by Agrobacterium-mediated transformation.The photosynthetic physiological characteristics of transgenic plants and control(‘Nanlin 895’poplars)were compared and analyzed.【Result】The cloned PEPC and PPDK genes all encode typical key enzymes of C4 photosynthesis.There were 5 lines transformed with PEPC gene and 3 lines transformed with PPDK gene.There were differences in gene expression among different lines of PEPC gene,up to 1.79 times,but there was no significant difference in the expression of proteins in leaves of different lines,and no significant difference in gene and protein expression among lines of PPDK gene;the expression of the two genes in leaves were higher than that in stems,and increased with time during plant growth and development;the expression of PEPC gene and PPDK gene were affected by light conditions,and increased 2-3 times under high illumination;the net photosynthetic rate of the transgenic lines showed a double peak at 11:00—14:00,which were significantly higher than that of the control group,with a maximum of 16.2%(PEPC-5 line);the stomatal conductance were higher at 12:00—16:00 than that of the control group;except PPDK-2 line,higher intercellular CO2 co

关 键 词：PEPC PPDK 转基因杨树 基因表达 光合作用 

分 类 号：S718.43[农业科学—林学] S718.46