THE ARABIDOPSIS ERECTA GENE ENCODES A PUTATIVE RECEPTOR PROTEIN-KINASE WITH EXTRACELLULAR LEUCINE-RICH REPEATS

Arabidopsis Landsberg erects is one of the most popular ecotypes and i s used widely for both molecular and genetic studies. I harbors the er ecta (er) mutation, which confers a compact inflorescence, blunt fruit s, and short petioles. We have identified five or mutant alleles from ecotypes Columbia and Wassilewskija. Phenotypic characterization of th e mutant alleles suggests a role for the ER gene in regulating the sha pe of organs originating from the shoot apical meristem. We cloned the ER gene, and here, we report that it encodes a putative receptor prot ein kinase. The deduced ER protein contains a cytoplasmic protein kina se catalytic domain, a transmembrane region, and an extracellular doma in consisting of leucine-rich repeats, which are thought to interact w ith other macromolecules. Our results suggest that cell-cell communica tion mediated by a receptor kinase has an important role in plant morp hogenesis.