绒毛白蜡2个MYB转录因子的活性鉴定及其表达分析

Characterization of Transcriptional Activity and The Expression Analysis of Two Fraxinus velutina Torr Transcription Factors

绒毛白蜡(Fraxinus velutina Torr.)FvMYB1和FvMYB2基因分别属于R1-MYB和R2R3-MYB转录因子家族成员。通过酵母(Saccharomyces cerevisiae)单杂交系统分别对其转录活性进行了鉴定,并分析了2个基因在不同组织中的表达模式。酵母滤纸显色反应结果表明两个转录因子均能激活下游报告基因(His和LacZ)的表达,具有转录激活功能;β–半乳糖苷酶活性检测法定量分析得出FvMYB1和FvMYB2的半乳糖苷酶活性分别为14.55 U和20.80 U。组织特异性分析显示,两者在各组织(根、子叶、茎、叶)中均有表达,但各自又表现出不同的组织表达差异,其中FvMYB1基因在茎中表达量最高,根中最低;而FvMYB2基因在各组织中的表达量无明显差异。

The Arizona ash （Fraxinus velutina Torr.） transcription factors FvMYB1 and FvMYB2 are two members of MYB family.The first one is a typical plant R1-MYB family gene while the later one belonged to R2R3-MYB family.In this study,their transcriptional activities were analyzed by using yeast（Saccharomyces cerevisiae）one-hybrid system.The results showed that both FvMYB1 and FvMYB2 could activate the expression of downstream report genes （His and LacZ）.β-Galaetosidase activity assay of two proteins in yeast showed that the transcriptional activities of FvMYB1 and FvMYB2 were 14.55 U and 20.80 U,respectively.RT-PCR was carried out to invest the expression patterns of FvMYB1 and FvMYB2 in different organs of Arizona ash.The results showed that both FvMYB1 and FvMYB2 genes were widely distributed in all the tested organs （root,cotyledon,stem and leaf）.However,the expression levels of them were different.For example,the highest amount expression of FvMYB1 was observed in stems and the lowest in roots while the gene expression level of FvMYB2 showed no dramatic differences in all the tested tissues.