Submitted to: American Society of Plant Biologists Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 3/16/2010
Publication Date: 5/10/2010
Citation: Horvath, D.P., Moriles, J., Hansen, S., Clay, S. 2010. Weeds Induce Permanent Changes in Expression of Photosynthetic Genes of Corn. American Society of Plant Biologists Annual Meeting, July 31-August 4, 2010, Montreal, Canada. Abs #P15010. http://abstracts.aspb.org/pb2010/public/P15/P15010.html. Interpretive Summary:
Technical Abstract: Regulation of bud dormancy is important for perennial plant survival. DORMANCY-ASSOCIATED MADS-BOX (DAM) genes have been implicated in regulating both dormancy induction and release in multiple plant systems. DAM genes are similar to SHORT VEGETATIVE PHASE (SVP) of arabidopsis. In arabidopsis, SVP inhibits flowering by binding to and repressing expression of FLOWERING LOCUS T (FT). Reduced expression of FT and a related gene TERMINAL FLOWERING 1 (TFL) is associated with dormancy induction in poplar. We hypothesized that DAM gene induction helps establish dormancy by reducing the expression of FT and related genes in most perennials. To test this hypothesis, we have over-expressed DAM1 from the perennial herbaceous weed leafy spurge in arabidopsis and shown that it represses the expression of arabidopsis FT. More recently, we have developed an antibody that could bind to the leafy spurge DAM1 gene. We have also cloned several FT-like and TFL-like genes from leafy spurge. Interestingly, some, but not all of or FT-like genes are down-regulated upon endodormancy induction and following other treatments that induce DAM gene expression. Chromatin immunoprecipitation assays with the DAM1 antibody pulled down DNA that was enriched with the differentially-expressed FT- and TFL-like genes, but not an FT-like gene that was constitutively expressed. Yeast one-hybrid experiments and other in vitro assays are under way to confirm the association and negative regulation of leafy spurge FT by DAM. Likewise, inducible constructs to over-express and repress DAM and FT genes in leafy spurge are under construction and will be used to transform leafy spurge, poplar, and possibly potato to confirm a role for these genes in perennial bud dormancy.