苦荞转录因子基因FtMYB56的克隆及其对黄酮合成的调控  

Transcription Factors Gene FtMYB56 Cloned from Fagopyrum tataricum,and Its Effects on Flavonoid Biosynthesis

作　　者：余艳 廖小龙 肖玉华 赵海霞[1] Yu Yan;Liao Xiaolong;Xiao Yuhua;Zhao Haixia(College of Life Science,Sichuan Agricultural University,Ya'an,625014)

机构地区：[1]四川农业大学生命科学学院,雅安625014

出　　处：《基因组学与应用生物学》2020年第10期4664-4671,共8页Genomics and Applied Biology

基　　金：四川农业大学创新训练计划(编号:201710626040)资助。

摘　　要：本研究基于苦荞转录组,筛选克隆一条与黄酮合成相关的MYB转录因子基因,命名为FtMYB56。生物信息学分析表明,该基因cDNA全长825 bp,编码蛋白含有274个氨基酸,包括R2和R3保守结构域,属于R2R3-MYB家族。实时荧光定量PCR检测结果显示,FtMYB56基因随苦荞发育在各组织具有不同的表达趋势,其中在叶中随发育期至花期达到峰值后迅速减少,而在生殖器官随种子成熟过程急速上升。FtMYB56在拟南芥中过表达的黄酮成分分析发现,两个阳性转基因株系中花青素、芦丁和总黄酮含量极显著增加(p<0.01),分别为野生型的3.51和3.98倍、1.20和1.42倍及0.77和0.68倍;基因表达量检测表明,拟南芥黄酮合成途径AtDFR、AtFLS和AtANS等晚期基因均极显著上调(p<0.01),而AtPAL、AtCHS、AtCHI和AtF3'H等早期基因表达无明显变化(p>0.05)。综上可见,苦荞转录因子FtMYB56可能通过增强黄酮合成途径晚期基因的表达,同时增加花青素和黄酮醇支路的合成代谢来提高黄酮物质的积累。In this study,a MYB transcription factor gene related to flavonoids synthesis,named FtMYB56,was screened and cloned from tartary buckwheat(Fagopyrum tataricum)based on its transcriptome.Bioinforma-tical analysis showed that FtMYB56 cDNA with 825 bp in full length encodes a putative protein of R2R3-MYB type transcription factor protein with 274 amino acids.Real-time PCR analysis indicated that FtMYB56 had a different expression profiles in different tissues in the whole growing period of tartary buckwheat.Particularly,its expression level decreased rapidly in leaves after reaching the peak at flowering stage,but increased dramatically in reproductive organs with seed development.Furthermore,in two FtMYB56-overexpression Arabidopsis lines,anthocyanins,rutin and flavonoids showed a significant higher accumulation than that of WT(p<0.01),and their concentrations were 3.51 and 3.98 times,1.20 and 1.42 times,and 0.77 and 0.68 times of wild type,respectively.Moreover,AtDFR,AtFLS and AtANS,the late biosynthetic genes(EBGs)in flavonoid pathway,were expressed prominently in transgenic Arabidopsis more than that in WT(p<0.01).However,for the expression levels of early biosynthetic genes(EBGs)including AtPAL,AtCHS,AtCHI and AtF3'H,there was no obvious difference between transgenic lines and with WT(p>0.05).In conclusion,transcription factor FtMYB56 from tartary buckwheat may improve flavonoids accumulation through enhancing the metabolic flux of anthocyanin and flavonol branches due to the higher expressions of the late biosynthetic genes(EBGs)in flavonoid pathway.

关 键 词：苦荞 MYB 转录因子 黄酮合成 调控 

分 类 号：S517[农业科学—作物学]