Abstract
In dicots, two cotyledon primordia are formed at two symmetrical positions in the apical part of the globular embryo. To reveal the molecular mechanism of cotyledon development, we screened Arabidopsis mutants defective in cotyledon formation and obtained two lines which carried allelic mutations. Map-based cloning showed that the gene encodes ACC1, a cytosolic multi-domain type of acetyl-CoA carboxylase. ACC1 catalyzes the production of the cytosolic pool of malonyl-CoA from acetyl-CoA and this malonyl-CoA pool is required for synthesis of various compounds including very long chain fatty acids (VLCFA). In situ hybridization showed that ACC1 is expressed ubiquitously in the embryo. To further investigate the role for ACC1 in cotyledon formation, we are currently examining expression patterns of STM and ANT, markers for shoot meristem and cotyledon formation, respectively. Results from this experiment will also be reported.
