RT Journal Article SR Electronic T1 Analysis of the Expression of CLA1, a Gene That Encodes the 1-Deoxyxylulose 5-Phosphate Synthase of the 2-C-Methyl-d-Erythritol-4-Phosphate Pathway in Arabidopsis JF Plant Physiology JO Plant Physiol. FD American Society of Plant Biologists SP 95 OP 104 DO 10.1104/pp.124.1.95 VO 124 IS 1 A1 Estévez, Juan M. A1 Cantero, Araceli A1 Romero, Cynthia A1 Kawaide, Hiroshi A1 Jiménez, Luis F. A1 Kuzuyama, Tomohisa A1 Seto, Haruo A1 Kamiya, Yuji A1 León, Patricia YR 2000 UL http://www.plantphysiol.org/content/124/1/95.abstract AB The discovery of the 2-C-methyl-d-erythritol-4-phosphate pathway for the biosynthesis of isoprenoids raises the important question of the nature and regulation of the enzymes involved in this pathway.CLA1, a gene previously isolated from Arabidopsis, encodes the first enzyme of the 2-C-methyl-d-erythritol-4-phosphate pathway, 1-deoxy-d-xylulose-5-phosphate synthase. We demonstrate this enzyme activity by complementation of the cla1-1mutant phenotype and by direct enzymatic assays. Based on mRNA and protein expression patterns this enzyme is expressed mainly in developing photosynthetic and non-photosynthetic tissues. The β-glucuronidase expression pattern driven from theCLA1 gene regulatory region supports the northern and protein data while also showing that this gene has some level of expression in most tissues of the plant. A mutation in theCLA1 gene interferes with the normal development of chloroplasts and etioplasts, but does not seem to affect amyloplast structure. Microscopic analysis also shows a pleiotropic effect of theCLA1 gene mutation in mesophyll tissue formation.