Journal Article

ASYMMETRIC LEAVES1, an Arabidopsis gene that is involved in the control of cell differentiation in leaves

Sun, Yue, Huang, Hai, Zhou, Qingwen, Fu, Yanlei, Zhang, Wei

2002

Overview

During leaf development, the formation of dorsal-ventral and proximal-distal axes is central to leaf morphogenesis. To investigate the genetic basis of dorsoventrality and proximodistality in the leaf, we screened for mutants of Arabidopsis thaliana (L.) Heynh. with defects in leaf morphogenesis. We describe here the phenotypic analysis of three mutant alleles that we have isolated. These mutants show varying degrees of abnormality including dwarfism, broad leaf lamina, and aberrant floral organs and fruits. Genetic analysis revealed that these mutations are alleles of the previously isolated mutant asymmetric leaves1 (as1). In addition to the leaf phenotypes described previously, these alleles display other phenotypes that were not observed. These include: (i) some rosette leaves with petiole growth underneath the leaf lamina; (ii) leaf vein branching in the petiole; and (iii) a leaf lamina with an epidermis similar to that on the petiole. The mutant phenotypes suggest that the ASYMMETRIC LEAVES1 (AS1) gene is involved in the control of cell differentiation in leaves. As the first step in determining a molecular function for AS1, we have identified the AS1 gene using map-based cloning. The AS1 gene encodes a MYB-domain protein that is homologous to the Antirrhinum PHANTASTICA (PHAN) and maize ROUGH SHEATH2 (RS2) genes. AS1 is expressed nearly ubiquitously, consistent with the pleiotropic mutant phenotypes. High levels of AS1 expression were found in tissues with highly proliferative cells, which further suggests a role in cell division and early cell differentiation.

• Publisher: Springer-Verlag,Springer
• Subject: Alleles / Amino Acid Sequence / amino acid sequences / anatomy & histology / Arabidopsis / Arabidopsis - genetics / Arabidopsis - growth & development / Arabidopsis Proteins / Arabidopsis Proteins - genetics / Arabidopsis Proteins - metabolism / Arabidopsis thaliana / Base Sequence / Biological and medical sciences / Cell differentiation / Cell Differentiation - genetics / cell division / Cell Division - genetics / Cell physiology / Chromosome Mapping / Cloning, Molecular / Corn / DNA / DNA-Binding Proteins / DNA-Binding Proteins - genetics / Epidermal cells / Fundamental and applied biological sciences. Psychology / Gene Expression / Genes, Plant / Genes, Plant - genetics / Genetic Complementation Test / Genetic mutation / genetics / growth & development / Leaves / metabolism / Molecular Sequence Data / Mutation / nucleotide sequences / Petioles / Phenotype / Phenotypes / plant development / Plant Epidermis / Plant Epidermis - anatomy & histology / Plant Epidermis - genetics / Plant Epidermis - growth & development / Plant Leaves / Plant Leaves - anatomy & histology / Plant Leaves - genetics / Plant Leaves - growth & development / plant morphology / Plant physiology and development / Plant Proteins / Plant Proteins - genetics / plant veins / Plants / Plants, Genetically Modified / pleiotropy / Proto-Oncogene Proteins c-myb / Sequence Homology, Amino Acid / Transcription Factors