A molecular approach to understanding root bud dormancy in leafy spurge

Leafy spurge is tenacious perennial weed of the Northern Plains. This plant maintains a perennial growth cycle by controlled production and growth of numerous underground adventitious buds. We are using molecular tools to identify signaling pathways that control underground adventitious bud growth and development in leafy spurge. Toward this end, we have used three techniques to identify genes that are differentially expressed concomitantly with the breaking of quiescence in underground buds of leafy spurge. These techniques include differential display of cDNAs, random cloning and sequencing of genes expressed in growing buds, and microarray technology. To date, we have identified more than 16 genes that are differentially expressed in underground buds of leafy spurge during dormancy break and growth initiation. A detailed expression analysis of these genes will allow them to be grouped by their responses to various signals known to play a role in control of underground bud growth. This information will be used to identify key cis-acting elements involved in the regulation of these genes. How such information on signal transduction processes may be used for developing new weed control strategies by the identification of novel target pathways and development of DNA-based herbicides is presented.