Molecular and phylogenetic analysis of MADS-box genes of MIKC type and chromosome location of SEP-lke genes in n wheat (Triticum aestivum L.).

Abstract

Transcription factors encoded by MIKC-type MADS-box genes control many important functions in plants, including Xower development and morphogenesis. The cloning and characterization of 45 MIKC-type MADSbox full-length cDNA sequences of common wheat is reported in the present paper. Wheat EST databases were searched by known sequences of MIKC-type genes and primers were designed for cDNA cloning by RT-PCR. Full-length cDNAs were obtained by 5 and 3 RACE extension. Southern analysis showed that three copies of the MIKC sequences, corresponding to the three homoeologous genes, were present. This genome organization was further conWrmed by aneuploid analysis of six SEP-like genes, each showing three copies located in diVerent homoeologous chromosomes. Phylogenetic analysis included the wheat MIKC cDNAs into 11 of the 13 MIKC subclasses identiWed in plants and corresponding to most genes controlling the Xoral homeotic functions. The expression patterns of the cDNAs corresponding to diVerent homeotic classes was analysed in 18 wheat tissues and Xoral organs by RT-PCR, real time RT-PCR and northern hybridisation.