Identification Of MADS-box Gene Family And Function Analysis Of CmMADS02 And CmMADS26 In Melon

Melon,a eudicot plant,is an annual herbaceous vine.Melon is an important horticultural crop and one of the nourishing fruit cultivated widely.And it is one of the top ten fruits in the world.Melon is an andromonoecious specie,where plants carry both male and perfect bisexual flowers.And its floral organ obviously belongs to the ABC(D)E model of floral development.A typical respiration climacteric fruit used to be experimental material in this study,which is an ideal candidate for studying fresh fruit development and ripening.The MADS-box gene family encodes a type of transcription factor,and plays a key role in the growth and development of plants,especially in development of reproductive organ,which is an important factor regulating floral development and fruit ripening.In this study,62 MADS-box genes were identified in the melon genome using bioinformatics methods.These genes were divided into type I M?,My and M8 subfamilies(26 members)and type II MIKCc subfamilies(36 members)by phylogenetic analysis.There were no genes in M?,AGL12,BS,TM8,and MIKC*subfamilies.Meanwhile,chromosomal location,intron-exon structure,distribution of conserved motifs and phylogenetic analysis of all genes was researched.The results showed that most of genes had the same character with that of their subfamilies,indicating that MADS-box gene family is relative conserved in structure and evolution in different species.Expression of all MADS-box genes was analyzed in melon by semi-quantitation PCR.Then we selected one or two genes with high expression and characteristic expression model according to previous results,and detected their expression pattern by RT-qPCR.The results showed that their expression patterns was different in every subfamilies,which indicated wide biological function.We cloned the full length cDNA of CmMADS02 and CmMADS26 by RT-PCR,and overexpression and RNAi vectors were constructed.And their function was analyzed in fruit ripening of melon by transient expression.The results showed that CmMADS26 promoted fruit ripening of melon probably.The phenotype analysis of T1 transgenic melon with CmMADS02 showed that CmMADS02 may control development of stamen in hermaphroditic flowers of melon.