Function Characterization Of Six Key MYB Transcription Factors Involved In Populus Wood Formation

Woods which rich in lignocellulosic biomass, not only is the main raw material of the plateand paper industry,but also an important raw material for biomass energy. Currently, the molecularmechanism of cellulosic biomass (wood) formation is not yet very clear, which is largely restrictedthe process of the efficient development and utilization of cellulosic biomass.Populus, whose cell wall formation subject to strict transcriptional regulation when woodformation, is the ideal mode woody plants and energy plants. To study the transcriptional networksof cell wall biosynthesis has a very important theoretical and practical significance in order toobtain efficient and easy conversion of biomass by means of genetic engineering modified poplarmaterial properties. MYB transcription factor is one of the largest numbers of transcription factorsof the plant-specific, and is a key regulatory factor in cell wall biosynthesis.It is very helpful toreveal the molecular mechanisms of transcriptional regulation during the formation of populuswood and also provide a theoretical reference for the genetic improvement of poplar fiber biomass.This article cloning and functional identification six MYB transcription factor （PdMYB10,PdMYB90，PdMYB92，PdMYB125，PdMYB167，PdMYB199） that involved in the regulation ofpoplar fiber biomass formation,then introduced the overexpression vector of candidate MYBtranscription into Arabidopsis by agrobacterium mediated method and filtering to obtaintransgenic plants. Comparative analysis between the transgenic plants and wild-type importantexperimental results has been obtained. There is a clear difference in flowering time, height, leaf,flower, pod and so on. And then we found the secondary wall in stem of PdMYB10, PdMYB90，PdMYB92，PdMYB125transgenic plants is significantly thinner by histological observation,whilethe converse of thing appared in PdMYB10and PdMYB199. Significant difference appeared afterwe had detected the expression levels of the target gene and key genes of cellulosic biomasssynthesis in Arabidopsis by real-time quantitative PCR. Thus, we have initially identified thefunction of key PdMYB gene that involved in the synthesis of cellulosic biomass by functionalverification the key genes involved in the synthesis of cellulosic biomass in Arabidopsis.