Abstract
The surfaces of higher plants are characterized by epidermis, which usually consists of a single layer of cells. The epidermis plays important roles in organ development with proper morphology, water retention, and gas exchange. However, little is known about the genes involved in epidermal differentiation in higher plants.The maize CRINKLY4 (CR4) gene, encoding a receptor-like kinase, controls an array of developmental processes including fate and differentiation. The Arabidopsis ACR4 gene is the CR4 gene homologue encoding protein with 60% amino acid identity and contains all the characteristic motifs of the maize CR4. To directly address the function of the ACR4, two knockouts of ACR4 gene have been obtained by screening T-DNA insertion lines. The acr4 mutation causes oblique and periclinal divitions to occur in the ovule integment, and defective cuticule formation in seed cost. These results suggest that the ACR4 gene is required for differentiation of the epidermis.
