RESUMEN

The organs of a higher plant show two fundamental axes of asymmetry: proximodistal and dorsoventral. Dorsoventrality in leaves, bracts, and petal lobes of Antirrhinum majus requires activity of the PHANTASTICA (PHAN) gene. Conditional mutants revealed that PHAN is also required for earlier elaboration of the proximodistal axis. PHAN was isolated and shown to encode a MYB transcription factor homolog. PHAN mRNA is first detected in organ initials before primordium initiation. The structure and expression pattern of PHAN, together with its requirement in two key features of organ development, are consistent with a role in specifying lateral organ identity as distinct from that of the stem or meristem. PHAN also appears to maintain meristem activity in a non-cell-autonomous manner.

Asunto(s)

Proteínas de Unión al ADN/genética , Genes de Plantas , Magnoliopsida/crecimiento & desarrollo , Proteínas de Plantas/genética , Brotes de la Planta/crecimiento & desarrollo , Proteínas Proto-Oncogénicas c-myb , Factores de Transcripción/genética , Alelos , Secuencia de Aminoácidos , Secuencia de Bases , Clonación Molecular , Hibridación in Situ , Magnoliopsida/genética , Meristema/genética , Meristema/crecimiento & desarrollo , Datos de Secuencia Molecular , Fenotipo , Brotes de la Planta/genética , ARN Mensajero/aislamiento & purificación , ARN de Planta/aislamiento & purificación , Homología de Secuencia de Aminoácido , Distribución Tisular