CLASS A, B, AND C MADS BOX GENES IN WHEAT (Triticum aestivum L.)

¹ Department of Bioscience, Fukui Prefectural University, 4-1-1 Kenjojima, Matsuoka-cho, Yoshida-gun, Fukui 910-1195, Japan

² Faculty of Agriculture, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan

³ Kihara Institute for Biological Research, Yokohama City University, 641-12 Mioka-cho, Totsuka-ku, Yokohama 244-0813, Japan

MADS box genes encode a family of transcription factors that contain a conserved DNA-binding domain, MADS box. It has been demonstrated that class A, B, and C MADS box genes play an important role in the genetic control of floral induction and development in Arabidopsis. To clarify the function of MADS box genes in wheat spike/spikelet/floret formation and development, we have started to study MADS box genes in wheat. PCR technique with degenerate primers matching the MADS box region was firstly utilized for characterizing wheat MADS box genes. Genomic Southern analysis with the degenerate PCR products as probes indicated that the wheat MADS box genes constitute a multigene family and are dispersed throughout the genome. Furthermore, RT-PCR analysis with degenerate primers revealed preferential expression of the MADS box genes in young spike at floret developing stage. Here we report the isolation of class A, B, and C MADS box genes, i.e., WAP1 (=TaMADS#11), WAP3 (=TaMADS#51) and WAG, respectively, by screening of a cDNA library from wheat young spike. Expression patterns of these MADS box genes were examined in an alloplasmic wheat showing homeotic transformation of stamens to pistils, and the possible functions of these genes are discussed.