PT - JOURNAL ARTICLE AU - Parker, Garry AU - Schofield, Rebecca AU - Sundberg, Björn AU - Turner, Simon TI - Isolation of <em>COV1</em>, a gene involved in the regulation of vascular patterning in the stem of <em>Arabidopsis</em> AID - 10.1242/dev.00441 DP - 2003 May 15 TA - Development PG - 2139--2148 VI - 130 IP - 10 4099 - http://dev.biologists.org/content/130/10/2139.short 4100 - http://dev.biologists.org/content/130/10/2139.full SO - Development2003 May 15; 130 AB - The molecular mechanisms that control the ordered patterning of vascular tissue development in plants are not well understood. Several models propose a two-component system for vascular differentiation. These components include an inducer of vascular tissue development and an inhibitor that prevents the formation of vascular bundles near pre-existing bundles. We have identified two recessive allelic mutants in Arabidopsis, designated continuous vascular ring (cov1), that display a dramatic increase in vascular tissue development in the stem in place of the interfascicular region that normally separates the vascular bundles. The mutant plants exhibited relatively normal vascular patterning in leaves and cotyledons. Analysis of the interaction of cov1 with a known auxin signalling mutant and direct analysis of auxin concentrations suggests that cov1 affects vascular pattering by some mechanism that is independent of auxin. The COV1 protein is predicted to be an integral membrane protein of unknown function, highly conserved between plants and bacteria. In plants, COV1 is likely to be involved in a mechanism that negatively regulates the differentiation of vascular tissue in the stem.