XVI International Botanical Congess

The MADS box genes encode a family of transcription factors in eukaryotes, some of which regulate the developmental process of floral organs in plants. We have focused our research on the molecular mechanism of strobilus development in gymnosperms and isolated two cDNA clones encoding MADS box genes in sugi. A phylogenetic analysis showed that the two genes, CjMADS1 and CjMADS2, belong to PISTILLATA (PI) subfamily. They form small multigene families within the sugi genome. CjMADS1 was expressed in the male strobili throughout the process of strobilus development induced by gibberellin treatment, whereas CjMADS2 was strongly expressed in male strobili especially when the meiotic division of pollen mother cell occurred. These results suggest that CjMADS1 and CjMADS2 play important roles as homeotic genes in the development of male strobili.