Molecular Cloning And Preliminary Study On Function Of Floral Related Genes BEAT In Wintersweet

Chimonanthus praecox L.blooms in winter and has a pleasant aroma.It is widely used in cut flowers and gardens.Aromatic is the most important ornamental feature of C.praecox,and benzyl acetate is one of the main aroma components.In our laboratory’s preliminary analysis of the floral constituents,it was found that the aromatic H93 accession had a high benzyl acetate content,while the unscented SW001 accession contained no benzyl acetate.On the basis of previous research in our laboratory,this study used the aromatic H93 and unscented SW001 accessions as the research materials to compare the differences in the content of benzyl acetate between the two materials in three periods.Screening differentially expressed genes controlling benzyl acetate synthesis in the transcriptome pool CpBEAT5,CpBEAT8,through real-time quantitative expression analysis and combined with the difference in benzyl acetate release,finding the link between gene expression and floral release.In addition we transferred the CpBEAT5 and CpBEAT8 into tobacco to initially explore their function.The main findings are as follows :1.Benzyl acetate was detected in scent H93,but not detected in any flowering period of scentless SW001.In different flowering period of H93,the amount of benzyl acetate varies with the substrate benzyl alcohol.They reached the peak at full flowering period,which was the same as that of total volatiles content.While no benzyl acetate was detected in SW001,a small amount of benzyl alcohol was detected at the final flowering period.2.In H93 and SW001 accessions,there was no difference in the protein sequence of CpBEAT5 or CpBEAT8.CpBEAT5 only contains one intron,which is a little different in two accessions,but CpBEAT8 does not have introns.3.In H93 and SW001 accessions,there are significant differences in the expression of CpBEAT5 or CpBEAT8.In H93,the expression of CpBEAT5 and CpBEAT8 at full flowering period was highest,and the trend of change in different periods is the same asbenzyl acetate.However,in SW001 CpBEAT5 andCpBEAT8 had the lowest expression in full flowering period.In petal baring period,full flowering period and final flowering period,the expression level of CpBEAT5 in H93 was much higher than that in SW001.The expression level of CpBEAT8 in H93 was nearly 4 times higher than that of SW001 in full flowering period.The expression levels of CpBEAT5 were lower than SW001 in both petal baring period and final flowering period.4.According to the promoter sequence alignment,there is a 17 base difference in the CpBEAT5 promoter between the H93 and SW001 varieties.And the promoter of H93 has one more TATA-box than SW001,which determines the beginning of gene transcription.The CpBEAT8 promoter is identical in both accessions.5.In the transgenic CpBEAT5 and CpBEAT8 tobacco flower,the volatile component analysis showed that both the wild type and transgenic plants could detect the substrate of benzyl alcohol,but not detected benzyl acetate and benzyl benzoate.