转BpCHS基因过量表达白桦叶片和韧皮部色素含量及植株表型分析  

Overexpression of BpCHS Confers Changes of Pigment Content in Leaves and Phloem and Other Phenotypic Traits in Transgenic Birch

作　　者：范志勇 姜晶[2] 王芳[2] 吕东林 顾宸瑞 李腾 姜静[2] Fan Zhiyong;Jiang Jing;Wang Fang;Lü Donglin;Gu Chenrui;Li Teng(Fourth middle school of Daqing City,Daqing 163711,P.R.China;State Key Laboratory of Tree Genetics and Breeding,Northeast Forestry University;Liaoning Forestry Vocation-Technical College)

机构地区：[1]黑龙江省大庆市第四中学,大庆163711 [2]林木遗传育种国家重点实验室(东北林业大学) [3]辽宁林业职业技术学院

出　　处：《东北林业大学学报》2018年第6期8-13,共6页Journal of Northeast Forestry University

基　　金：国家重点研发计划课题(2017YFD0600603)

摘　　要：查尔酮合酶(chalcone synthase,CHS)是类黄酮类物质生物合成途径中的关键酶,该酶不仅在植物花色及叶色形成中起决定作用,同时还参与植物的多种生理生化过程。为了揭示白桦查耳酮合酶的功能,试验以白桦成熟合子胚为受体,以35S启动子驱动的BpCHS3为载体,采用农杆菌介导法开展转BpCHS3基因研究,利用含50 mg/L Hyg的培养基进行抗性筛选转基因株系,同时结合目标基因的PCR验证,试验获得转BpCHS3白桦15个阳性株系,分子检测证明,目标基因整合到白桦基因组中,BpCHS3能在转基因白桦中过量表达。2年生转基因白桦生长及表型观察发现,转基因白桦与WT株系的苗高及地径差异不显著,而侧枝数显著高于WT株系(P<0.01);转基因白桦叶片呈现浅绿色、茎杆为浅黄绿色,光合色素及花青素质量分数测定显示,叶片组织中转基因白桦的叶绿素、类胡萝卜素及花青素质量分数均显著低于WT株系(P<0.01),花青素相对质量分数均值低于WT株系的45.99%;韧皮组织中转基因株系的光合色素质量分数均高于WT,花青素相对质量分数与WT株系差异不显著。转基因白桦中BpCHS1和BpCHS2家族基因表达特性分析发现,相对WT株系转基因白桦的BpCHS1和BpCHS2基因均呈下调表达(OE1株系除外),认为过量表达BpCH3白桦中发生了BpCH1和BpCH2的共抑制现象。Chalcone synthase （CHS） is a key enzyme in the flavonoid biosynthesis pathway. It not only plays a decisive role in the formation of plant flower color and leaf color, but also participates in many other physiological and biochemical processes in plants. In order to reveal the function of CHS in Betula platyphylla , the mature zygotic embryo of B. platyphylla was used for transgenic experiment through Agrobacterium -mediated transformation. The 35S promoter-driven BpCHS3 was used as an expression vector. We obtained 15 positive BpCH3 transgenic lines, and confirmed by target gene PCR and qPCR. BpCH3 gene was over expressed in these transgenic lines. There were no difference in height and diameter, whereas the number of sylleptic branch was significant higher in transgenic lines than that of wild type （ P 〈0.01）. Leaf color of transgenic plants was in light green, and stem in light yellow green. The transgenic plants were significantly lower for chlorophyll and carotenoid than wild type （ P 〈0.01）. Anthocyanin was 45.99% lower than wild type. Photosynthetic pigment content of transgenic lines in phloem was higher than that of WT, but no difference for anthocyanin. Analysis of gene expression profiles of BpCHS1 and BpCHS2 in transgenic birch found that both BpCHS1 and BpCHS2 genes were down-regulated （except OE1）, suggesting that co-suppression of BpCH1 and BpCH2 occurred in over-expressed BpCHS3 birch.

关 键 词：查耳酮合酶 转基因白桦 花青素 

分 类 号：S722.3[农业科学—林木遗传育种]