Function Research Of BpMADS12 Gene In Betula Platyphylla

Transcription factors of MADS-box family play an important role in regulating flowering time,flower organ formation,and development of vegetative organs,such as the roots,stems and seeds.In the study,BpMADS12 as the research object,the expression characteristics of BpMADS12 gene,phenotype,physiology and transcriptome of BpMADS12 overexpression birch plants were observated to reveal the birch BpMADS12 gene function,the results as follows:Expression pattern of BpMADS12 gene was analysised in different tissue of birch using qRT-PCR,the results showed that the abundance of BpMADS12 were higher in leaves,crowns,male flowers and the axillary buds than others tissues from late June to early August.Cis-elements in promoter of BpMADS12 gene were analysised using PLACE(htt p://www.dna.affrc.go.jp/PLACE/)and PlantCARE(http://bioinfor matics.psb.ugent.be/webtools/plantcare/html/),the results showed that it contain cis elements responding for flowering,cytokinins response,and low temperature and drought stress response.Expression pattern of BpMADS12 gene promoter in Arabidopsis was analysised,the results showed that GUS were detected in all tissue at the reproductive growth phase.At the same time,the results of stress experiment showed that this gene involved in drought response.Flowering time and the number of male and female inflorescences of BpMADS12 overexpression lines were observed.Compared with nontransgenetic lines,flowering time of overexpression lines was not earlier,and the number of female inflorescences was increased than nontransgenetic lines,the number of female small flowers and seed vigor were decreased in overexpression lines.Transcriptome of BpMADS12 overexpression lines and nontransgenetic lines were analysised,the results showed that differentially expressed genes involved in lignin and BR synthesis pathway were significant enriched.The number of differentially expressed genes in lignin and BR synthesis pathway was 180 and 236,respectively.It indicated that,BpMADS12 can control the synthesis of lignin and BR.Contents of lignin and BR were higher in BpMADS12 overexpression lines than those of nontransgenetic lines.In conclusion,we found that BpMADS12 gene did not promote birch flowering,however,played roles in the number of female inflorescences and lignin and BR biosynthesis.