Expression And Function Analysis Of Material Related MYB Genes In Chinese Fir

Transcription factor has become popular in molecular biology in recent years, which specificallybind to the regulatory regions of target genes as cis-acting elements to regulate the expression of targetgenes. MYB transcription factor is one of the largest transcription factors in plants, playing an importantrole in the regulation of plant. This study chooses China fir as materials, which is regarded as animportant fast-growing softwood timber species. The main results are as follows:1. The results of Subcellular localization suggest that, sGFP-ClMYB1localized in the nucleus, whereassGFP-ClMYB2not only localized in the nucleus, but also located on the cell membrane and cytoplasmof some organelles.2. Real-time quantitative PCR is used to exam the expression of the two MYB genes cloned from fir.The results showed that: ClMYB1is mainly expressed in coniferous and woody stems; ClMYB2ismainly expressed in the roots and woody stems, and the expression levels in non-woody stem was lessthan woody stem. Quantitative PCR revealed that the expression patterns of ClMYB1and ClMYB2inwoody and non-woody stems are similar. Both of them are mainly expressed in woody stems andincreased with lignification of stem. Co-expression analysis of ClMYB1and ClMYB2with12fir ligninbiosynthesis enzyme genes suggested that ClMYB1was positively correlated with ClCCoAOMT1,ClPAL3. ClMYB2was positively correlated with ClCCoAOMT1, ClPAL3, ClCOMT and ClCCR1. Theseresults indicate that ClMYB1, ClMYB2positively regulate ClCCoAOMT1and ClPAL3genes involved inthe fir wood formation.3. Results of situ hybridization showed ClMYB1is mainly expressed in vascular tissue of leaves, andClMYB2is mainly expressed in root xylem, only a slight expression in vascular tissue of leaves, so thesignal of ClMYB2is not strong. Taken together, ClMYB1, ClMYB2are mainly expressed in the xylem ofwoody stems.4. Leaves of ClMYB2transgenic lines are much smaller than control, but the texture is thick and thecolors are deep. Petioles are stiffer in ClMYB2transgenic lines. Section II of transgenic tobacco stemand control showed no color and no difference in Wiesner staining experiments, while the IV and VIshowed deep and dark red. LTGA showed that the lignin of transgenic tobacco was significant higherthan the control. Results of quantitative PCR revealed that the expression level of CCoAOMT1,CCoAOMT2, CCoAOMT3, PAL and PAL4in transgenic lines increased compared to the control, whilethe expression of CHS was reduced and4CL1had no changes. These results indicated ClMYB2participate in lignin biosynthesis by regulating the expression of some genes involved in ligninbiosynthesis.