Submitted to: Workshop Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: February 1, 2008
Publication Date: May 1, 2008
Citation: Anderson, J.V., Foley, M.E., Gu, X. 2008. Dormancy regulation in reproductive structures of weedy plants; a comparison between seeds and vegetative buds. Workshop Proceedings. Workshop: Sleeping Beauties Program and Abstracts, Berlin-Dahlem, Germany, May 18-20, 2008. Page 15. Technical Abstract: Dormancy in seeds and vegetative buds is one of the key characteristics which allow weedy plants to escape conventional chemical, cultural, mechanical, and bio-control measures currently available to weed managers. Identifying genetic and physiological targets that regulate dormancy induction and release in these reproductive structures could provide new clues for developing future control measures. Leafy spurge (Euphorbia esula L.) is being used as a model to study well-defined phases of dormancy in underground adventitious buds of perennial weeds, while weedy rice (Oryza sativa L.) is being used as a model to study dormancy in seeds of annual weeds. Differential expression of transcripts associated with well-defined phases of dormancy in leafy spurge was accomplished using a 23 K element Euphorbiaceae-specific microarray, whereas quantitative trait loci (QTL) analysis was used to identify 7 chromosomal segments associated with natural variation in seed dormancy. Microarray analysis identified 999 differentially expressed genes (p = 0.005) in leafy spurge crown buds, which highlighted multiple pathways and physiological processes associated with dormancy transitions including cell cycle, chromatin remodeling, glycolysis, protein and lipid metabolism, redox potential, transport, jasmonic acid responsiveness, and stress. Microarray analysis also identified a specific DORMANCY ASSOCIATED MADS BOX (DAM) transcription factor that likely regulates FLOWERING LOCUS T (FT) and supports the hypothesis that pathways linking flowering and dormancy overlap. Map-based cloning of the QTL on the short arm of chromosome 7 (qSD7-1) revealed that its underlying gene has pleiotropic effects on weedy rice seed dormancy, red pericarp color, and grain weight. This gene encodes a predicted basic helix-loop-helix DNA binding domain transcription factor (OsbHLH017) that is truncated due to a 14 bp deletion. Microarray analysis of isogenic lines comparing alleles of the transcription factor suggests that this weedy rice dormancy gene controls cell cycle and cell transport in addition to proanthocyanidin production.