Cloning And Function Analysis Of GBM5 And GBM6 In Ginkgo Biloba L.

Ginkgo biloba L.belongs to the family of the genus Gymnosperm,and is one of the oldest surviving species native in China.The long juvenile period of the Ginkgo biloba tree has seriously hinders the progress of Ginkgo biloba breeding,resulting in the lack of good varieties and limiting the economic and social value of Ginkgo biloba.Studies have shown that members of the mads-box gene family can shorten juvenile period of plants and promote flowering.In this study,15 MADS-box genes were screened by Ginkgo biloba transcriptome sequencing data,and sequence analysis and expression analysis were performed for Gb16301(named GBM5)and Gb01884(named GBM6).The main findings are as follows:1.Identification of genetic members of MADS-box family in Ginkgo bilobaFifteen Ginkgo biloba MADS-box family genes were screened from the sequencing data of Ginkgo biloba.The protein encoded by 15 genes was between 150-^450 aa and the molecular weight was between 19 373.4-50 951.76 Da.Combined with the chromosomal location information in the whole genome sequencing data of Ginkgo biloba,the distribution of 15 MADS-box genes in Ginkgo biloba is not uniform in the chromosome.Cluster analysis showed that there were 2 of the 15 MADS-box genes belonging to the type I My subfamily,and 13 of the MIKC type genes were further classified into TM3,TM8,AG,GGM13 and SVP subfamilies.2.Cloning of GBM5 gene and GBM6 geneThe full-length CDS sequence of GBM5(Gb16301)gene and GBM6(Gb01884)were cloned by RT-PCR,using the cDNA of Ginkgo biloba stem apex as template and designing specific primers based on the sequence information in the transcriptome data.GBM5 contains a 732 bp open reading frame predicted to encode a protein of C1188H1923N357O366S12.The GBM6 gene contains a 756 bp open reading frame predicted to encode a protein of C2251H3748N756O917S163.3.Expression analysis and expression vector construction of ginkgo GBM5 and GBM6Combined with cluster analysis results and expression analysis data,it was found that Ginkgo biloba GBM5 gene has high homology with AG genes of other species suchas Cycas revoluta,and the expression pattern is similar to that of AG genes in other plant,expression in stem ends and leaves.As the flower bud differentiation process showed a significant downward trend.The expression level of GBM6 in Ginkgo biloba leaves is higher.The expression of GBM6 in the stem end and leaves of Ginkgo biloba is along with.The flower bud differentiation process showed a significant downward trend,and the extent of decline in the leaves was larger.In this study,overexpression vectors of pEGAD-GBM5 and pEGAD-GBM6 were successfully constructed to further investigate the functions of GBM5 and GBM6 genes.