高羊茅FaCONSTANS基因的表达及功能分析

Expression and function analysis of FaCO gene in Festuca arundinacea

摘要:

植物由营养生长向生殖生长转变过程中光周期调控起着重要的作用。CONSTANS (CO) 是光周期途径中的特有基因，为探讨高羊茅FaCONSTANS (FaCO) 基因响应日照长短从而启动植物开花的机理，利用实时荧光定量qRT-PCR技术分析在长日照、短日照、持续光照、持续黑暗条件下FaCO基因的表达水平。构建过表达载体p1300-FaCO，利用农杆菌介导法遗传转化拟南芥，构建沉默载体p1300-FaCO-RNAi遗传转化高羊茅。结果表明，FaCO基因的表达受光周期调控，与生物钟控制的昼夜节律相关。在长日照条件下FaCO基因促进拟南芥开花，且恢复拟南芥突变体开花表型。RNAi沉默FaCO基因的高羊茅转基因植株晚花或者一直处于营养生长阶段。本研究初步探究高羊茅FaCO基因对开花过程的调控，这将有助于更进一步了解该基因的生物学功能。

关键词:高羊茅，光周期调控基因，表达分析，载体构建

Abstract:

Photoperiod plays an important role in transformation from vegetative growth to reproductive growth in plants. CONSTANS (CO), as a unique gene in the photoperiod pathway, responds to changes of day length to initiate flowering in the plant. In this study, the expression level of FaCONSTANS (FaCO) gene under long-day, short-day, continuous light and continuous darkness conditions was analyzed by real-time quantitative PCR. We constructed the over-expression vector p1300-FaCO and infected into Arabidopsis thaliana by Agrobacterium-mediated method. We constructed the silencing vector p1300-FaCO-RNAi and infected into Festuca arundinacea by Agrobacterium-mediated method. The expression of FaCO gene was regulated by photoperiod. The over-expression of FaCO promoted flowering in wild type of Arabidopsis thaliana under long day condition and rescued the late flowering phenotype in co-2 mutant of Arabidopsis thaliana. Silencing FaCO gene in Festuca arundinacea by RNAi showed late-flowering phenotype or always kept in the vegetative growth stage. Our understanding the function of FaCO in flowering regulation will help further understand biological function of this gene in Festuca arundinacea.

Key words:tall fescue, photoperiodic regulation gene, expression analysis, vector construction