Submitted to: Weed Science
Publication Type: Review Article
Publication Acceptance Date: 3/31/2008
Publication Date: 7/1/2008
Citation: Varanasi, V., Slotta, T., Horvath, D.P. 2008. Cloning and characterization of a critical meristem developmental gene (EeSTM) from leafy spurge (Euphorbia esula). Weed Science. 56:490-495. DOI:10.1614/WS-07-192.1. Interpretive Summary: We have cloned and characterized a gene named SHOOTMERISTEMLESS that is needed for meristem development and growth from the invasive perennial weed leafy spurge. The gene is named SHOOTMERISTEMLESS because when it is mutated, plants only produce hypocotyls and do not form shoots. When we looked at the region of the gene (called the promoter) that causes it to be turned on and off, we discovered several short sequences that may play a role in the regulation of this gene. One sequence in particular was shown to be similar to a sequence previously known to cause gene expression in roots. We suggest that because SHOOTMERISTEMLESS is required for bud development, the expression of this gene in the roots of leafy spurge explains why leafy spurge produces buds on its roots, and may provde a novel target that could be used to inhibit bud formation and help control this weed.
Technical Abstract: SHOOTMERISTEMLESS (STM) encodes a member of the class I KNOX homeodomain protein family that is required for meristem development and maintenance. We have isolated both genomic and two different cDNA clones of STM from the perennial weed leafy spurge. A comparison to other class I KNOX genes indicates that the EeSTM represent an orthologue of AtSTM and not one of the other Class I KNOX gene family members. 5' Race indicated that the transcription initiation site is close to the start of translation and is conserved between arabidopsis and leafy spurge. Putative cis-acting elements were identified in the EeSTM promoter, including a tuber-specific sucrose-responsive element which could play a major role in the expression of EeSTM in root tissue.