Submitted to: Weed Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 11, 2005
Publication Date: December 1, 2005
Citation: Horvath, D.P., Soto-Suárez, M., Chao, W.S., Jia, Y., Anderson, J.V. 2005. Transcriptome analysis of paradormancy release in root buds of leafy spurge (Euphorbia esula). Weed Science. 53(6):795-801.
Interpretive Summary: We have developed a new tool (microarrays) for studying how more than 1500 different genes are turned on and off in underground shoots of the perennial weed leafy spurge when they begin to grow. These studies have identified several physiological processes such as cell division and general responses to the plant hormone gibberellic acid that are induced when the buds begin to grow. Additionally, we report the down-regulation of metabolic processes needed for the production of a group of plant metabolites called flavones. Flavones are suspected to inhibit the transport of another plant hormone known as auxin. Auxins allow growing buds to inhibit growth of other buds so that the plant does not waste resources by allowing all buds to grow at once. This observation may lead to development of compounds or procedures that will induce growth in all dormant buds at once, which will greatly enhance efficacy of weed control treatments.
We have developed a 2654 element Euphorbiaceae cDNA microarray using 1886 sequenced cDNAs from leafy spurge, 384 cDNAs from cassava, and 384 control genes from other plant, animal, and bacterial species. This array was used to follow changes in gene expression in root buds of leafy spurge following loss of paradormancy. The differential expression of several genes previously identified as being induced following loss of paradormancy was confirmed by the microarray analysis. In addition, genes encoding an asparagine synthase, a phosphate inducible protein, and a curculin-like (mannose-binding)lectin family protein were found to be rapidly up-regulated upon loss of paradormancy. A set of genes involved in flavanoid biosynthesis were found to be rapidly down regulated upon loss of paradormancy. The potential impact of flavanoid biosynthesis on auxin transport in response to bud growth is discussed.