RESUMEN
We have isolated three Apetala2 (Ap2)-like genes from petunia and studied their expression patterns by in situ hybridization. PhAp2A has a high sequence similarity to the A function gene Ap2 from Arabidopsis and a similar expression pattern during flower development, suggesting that they are cognate orthologs. PhAp2B and PhAp2C encode for AP2-like proteins that belong to a different subgroup of the AP2 family of transcription factors and exhibit divergent, nearly complementary expression patterns during flower development compared with PhAp2A. In contrast, all three PhAp2 genes are strongly expressed in endosperm. The phenotype of the petunia A-type mutant blind cannot be attributed to mutations in the petunia Ap2 homologs identified in this study, and reverse genetics strategies applied to identify phap2a mutants indicate that PhAp2A might not be essential for normal perianth development in petunia. Nevertheless, we show that PhAp2A is capable of restoring the homeotic transformations observed in flowers and seed of the ap2-1 mutant of Arabidopsis. Although the interspecific complementation proves that PhAp2A encodes a genuine Ap2 ortholog from petunia, additional factors may be involved in the control of perianth identity in this species.
Asunto(s)
Genes de Plantas , Proteínas de Homeodominio/genética , Proteínas Nucleares/genética , Petunia/crecimiento & desarrollo , Petunia/genética , Proteínas de Plantas , Secuencia de Aminoácidos , Arabidopsis/genética , Arabidopsis/crecimiento & desarrollo , Proteínas de Arabidopsis , Secuencia de Bases , Mapeo Cromosómico , ADN de Plantas/genética , Flores/crecimiento & desarrollo , Regulación del Desarrollo de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Prueba de Complementación Genética , Hibridación in Situ , Datos de Secuencia Molecular , Familia de Multigenes , Mutagénesis Insercional , Mutación , Fenotipo , Semillas/crecimiento & desarrollo , Homología de Secuencia de Aminoácido , Especificidad de la EspecieRESUMEN
The dTph1 transposable element family of Petunia hybrida line W138 consists of between 100 and 200 members. A strategy that allows simultaneous detection of individual elements is described. Sequences flanking dTph1 elements are amplified by means of a ligation-mediated PCR. The resulting fragments are locus-specific and can be analysed by polyacrylamide gel electrophoresis. One of the applications of Transposon Display is the isolation of dTph1-tagged genes. Fragments that co-segregate with a mutant phenotype can be extracted from the gel and reamplified, providing access to tagged genes, as demonstrated in a reconstruction experiment. Data on the molecular identification of a phenotypic mutant, isolated in a random tagging experiment is also presented. Upon sequencing, the obtained candidate fragment was found to be identical to part of the previously identified Fbp1 gene.