虎杖转录因子PcMYB2的表达特性和功能分析

Expression and Function Analysis of Transcription Factor PcMYB2 from Polygonum cuspidatum

对虎杖R2R3-MYB转录因子PcMYB2进行转录活性鉴定和表达特性分析,并在转基因拟南芥和转基因毛状根中进行功能研究。利用酵母单杂交试验分析PcMYB2的转录活性;实时荧光定量PCR(RT-qPCR)技术检测虎杖中PcMYB2的表达模式;DMACA法检测PcMYB2转基因拟南芥和虎杖毛状根中的原花青素含量。酵母单杂试验表明,PcMYB2具有转录激活活性;RTqPCR结果显示,PcMYB2在虎杖根、茎、叶中均有表达,在叶中表达量最高,并且ABA和H_(2)O_(2)外源处理可诱导叶片中PcMYB2的表达;与野生型拟南芥相比,转基因拟南芥种皮颜色加深,原花青素含量为野生型的1.8倍;与野生型毛状根相比,转基因毛状根DMACA染色更深,原花青素含量为野生型的2.3倍。PcMYB2具有转录激活活性,且促进植物原花青素的生物合成。

This work aims to identify the transcriptional activity and expression profile of PcMYB2,encoding an R2R3-MYB transcription factor from Polygonum cuspidatum,and to evaluate the biological functions of PcMYB2 in transgenic Arabidopsis thaliana plant and transformed P.cuspidatum hairy roots.The yeast one hybrid was used to analyze transcriptional activity.And quantitative real time PCR(RT-qPCR)technique was applied to detect the tissue-specific expression profile of PcMYB2 in P.cuspidatum and its expression pattern in responses to stress treatments.The DMACA method was to determine the contents of proanthocyanidins in PcMYB2-transgenic A.thaliana and P.cuspidatum hairy roots.The yeast one hybrid experiment showed that PcMYB2 had transcriptional activity.The PcMYB2 gene was expressed in the roots,stems and leaves of P.cuspidatum,with the highest expression in the leaves,and the expression of PcMYB2 gene in the leaves was induced after application of ABA or H_(2)O_(2).Transgenic A.thaliana presented an increase in the pigmentation of mature seed compared with the wild type,and the proanthocyanidins content was 1.8-fold higher than that of the wild type.Staining of the hairy roots with DMACA was darker compared with wild type,and proanthocyanidins content was 2.3-fold higher.Altogether,this study reveals that PcMYB2 has transcriptional activity and may promote the proanthocyanidins biosynthesis.