Submitted to: Weed Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 23, 2006
Publication Date: September 1, 2006
Citation: Horvath, D.P., Anderson, J.V., Soto-Suarez, M., Chao, W.S. 2006. Transcriptome analysis of leafy spurge (Euphorbia esula) crown buds during shifts in well-defined phases of dormancy. Weed Science. 54:821-827.
Interpretive Summary: We have studied ~1,800 different genes to see how they are turned off and on in underground buds of the invasive perennial weed leafy spurge when the plant experiences seasonal changes. These buds of leafy spurge enter and exit various states of dormancy beginning in late summer through spring when the buds are released and they form new shoots. We observed a large number of genes that are known to be turned on or off by the plant hormone gibberellic acid were affected when the buds went from summer dormancy (paradormancy) to fall dormancy (endodormancy). Surprisingly, we also noticed that a number genes involved in photosynthesis were temporarily turned on in the buds once they were in their fall dormant state. We also were surprised to see a number genes involved in responding to the hormone ethylene (normally associated with fall color changes) being turned on in the buds during winter dormancy (ecodormancy). Now that we have genes that we know are turned on and off in response to seasonal changes, we should be able to begin deciphering the underlying signals and mechanisms that control dormancy in perennial plants.
Microarray analysis was used to follow changes in gene expression coinciding with seasonal changes in the dormancy status of crown buds of field-grown leafy spurge. Known cold-regulated genes were induced and numerous GA-responsive genes were down-regulated during the transition from paradormancy to endodormancy. Genes involved in photomorphogenesis were induced during endodormancy. Also, ethylene signaling responses were observed during ecodormancy rather than endodormancy. These results provide additional insights into the signals regulating expression of several genes previous associated with transition from paradormancy to growth in root buds.