Plant & Animal Genomes XVI Conference

January 12-16, 2008
Town & Country Convention Center
San Diego, CA

Regulation Of FLC-Like Genes And Bud Dormancy In Poplar

Gary D. Coleman , Kuang-Yu Chen

  Department of Plant Science and Landscape Architecture, University of Maryland, College Park, MD, 20742, USA

MADS-box genes regulate a number of developmental processes in plants. In Arabidopsis, MADS-box genes have been shown to be important regulators of flowering. The vernalization pathway involves the Arabidopsis Flowering Locus C (FLC), a MADS box transcription factor and a repressor of flowering. The vernalization pathway involves the initiation and maintenance of repressive chromatin in FLC. Because of the similarities between vernalization induced flowering and bud dormancy we were interested in knowing if similar regulatory factors might be involved in both processes. By searching the Poplar genome we identified 4 putative FLC-like genes. Transcripts for all four putative FLC-like genes were detected in vegetative apices and buds. Transcript abundance of one gene, PtFLC2, appears to be down regulated by both short-day photoperiods and cold-temperatures. In addition, multiple splicing variants of PtFLC2 were detected and the production of specific splice variants was associated with cold-temperatures. Results with transgenic Poplars that either overexpress PtFLC2 or express PtFLC2 RNAi indicate a regulatory role for PtFLC2 in the timing and development of vegetative buds. Furthermore, studies using both transgenic Arabidopsis and Poplar expressing PtFLC2 splice variants suggest a regulatory role for specific splice variants in development. These results provide a framework for elucidating the regulatory components of bud dormancy. We propose that PtFLC2 may act as a repressor of genes involved in both vegetative bud development and dormancy and is regulated by epigenetic changes as well as alternative splicing.