Analysis Of MIKC~C-type MADS-box Gene Family In Gossypium Hirsutum L.

MIKCC-type MADS-box genes encode transcription factors that are involved in plantdevelopmental control and signal transduction. With the complication of whole genome sequencing ofArabidopsis, rice, vitis, the analysis of MADS-box genes has been successively complicated. However,due to the big size and allotetraploid of Gossypium hissutum genome, the genome of Gossypiumraimondii, considered as the contributor of the D subgenome to G. hirsutum, was sequenced until2012. Therefore previous research on MADS-box genes of cotton is little.In this study, MIKCC-type MADS-box genes were obtained based on the genome of Gossypiumraimondii and ESTs in NCBI and DFCI. These genes were analyzed by bioinformatics software onphylogenetic analysis, chromosomal localization and motif analysis. Expression analysis in multipletissues and floral organs was measured by Real-time quantitative PCR (qRT-PCR). The study’s mainresults were as follows:1. Based on the genome of Gossypium raimondii, NCBI and DFCI databases,53MIKCC-typeMADS-box genes were obtained, including34newly cloned genes, named from GhMADS37toGhMADS70.2. Phylogenetic analysis of these genes with those from Arabidopsis and grapevine showed that theFLC and AGL12subfamilies were absent in G. hirsutum. Chromosomal location showed ninegroups at the same locus were deduced to be from different subgenomes. The analysis of motifshowed that the same subfamily had the similar motif and great divergence existed in differentsubfamilies.3. Expression analysis in multiple tissues of53MADS-box genes showed the genes belonging to SVPsubfamily that relate to flowering time all had high expression level in apical bud, so we deducedthat they may have functional redundancy. In another subfamily SOC1, only GhMADS60hadhighest expression level in apical bud, so it was deduced that GhMADS60had a main function inSOC1subfamily. SEP, AG, AP3-PI that relate to the development of floral organs had highexpression level in flower, and the genes in the same subfamily had the similar expression pattern.4. Floral expression patterns showed that GhMADS41and42in API-FUL (A class) showed thehighest expression levels in sepals, and high expression of B-class genes was observed in petals andstamens. AG genes belonging to C and D classes were strongly expressed in stamens, carpels, andovules. As for E class, five of the seven SEP-subfamily genes that were highly expressed in flowershad elevated expression in all floral organs. The BS (B sister class) genes had high expression inovules and carpels.5. The transgenic result of GhMADS13belonging to AGL6subfamily showed that the highertranscriptional level of transgenic Arabidopsis was consistent the shorter plant, less seeds andshorter sillique. It was conjectured that GhMADS13had a negative effect on ovule development.