RESUMO
MADS-box genes have been shown to play a major role in defining plant architecture. Recently, several MADS-box genes have been reported that are highly expressed in the ovule. However, only for the Petunia genes FBP7 and FBP11 has a function in defining ovule identity been shown. We have isolated a rice MADS-box gene named OsMADS13. Expression analysis has shown that this gene is highly expressed in developing ovules. In order to facilitate a detailed characterization of rice ovule-expressed genes, a comprehensive morphological description of ovule development in rice has been performed. The predicted amino acid sequence of OsMADS13 shows significant homology with ZAG2, a maize MADS-box gene, which is also expressed mainly in the ovule. Mapping of the gene in the rice genome showed that it is located on chromosome 12, which is syntenic to two maize regions where ZAG2 and its paralogous gene ZMM1 have been mapped. Our results suggest that OsMADS13 is the ortholog of ZAG2 and ZMM1 and might play a role in rice ovule and seed development.
Assuntos
Proteínas de Ligação a DNA/genética , Oryza/genética , Proteínas de Plantas/genética , Fatores de Transcrição/genética , Sequência de Aminoácidos , Mapeamento Cromossômico , Genoma de Planta , Proteínas de Domínio MADS , Dados de Sequência MolecularRESUMO
Hazelnut (Corylus avellana L.) is a species of economic interest that shows a peculiar floral biology. Unlike most of the angiosperms, which produce ovules during floral development such that they are ready for pollen at anthesis, hazelnut ovary development is delayed and triggered by compatible pollination. In order to elucidate the mechanisms regulating this unusual process and the role of the MADS box genes in ovary development, a cDNA library from pollinated styles of hazelnut was screened with a mixture of MADS box genes from different plant species. CaMADS1 (Corylus avellana MADS box), a floral-specific MADS box gene, was isolated, and characterized as belonging to the sub-family of the AGAMOUS genes. Northern blot, RT-PCR analyses and in situ hybridization experiments show a precise correlation between ovary development and CaMADS1 expression, indicating a role of this MADS box gene in the processes of floral organogenesis.
Assuntos
Regulação da Expressão Gênica de Plantas , Proteínas de Homeodomínio/genética , Nozes/genética , Filogenia , Sequência de Aminoácidos , Sequência de Bases , Primers do DNA , Proteínas de Ligação a DNA , Regulação da Expressão Gênica no Desenvolvimento , Proteínas de Homeodomínio/biossíntese , Proteínas de Homeodomínio/química , Proteínas de Domínio MADS , Dados de Sequência Molecular , Nozes/crescimento & desenvolvimento , Nozes/metabolismo , Proteínas de Plantas , Caules de Planta , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sementes , Fatores de TranscriçãoRESUMO
Various factors (pollen diameter, in vitro germination and tube length, in vivo growth rate in selfed and nonselfed styles) which could possibly contribute to the competitive ability of pollen were investigated on 30 Zea mays L. inbred lines. The only factor with which pollen diameter was positively correlated was in vitro pollen-tube growth. Traits related to the early stages of growth (in vitro germination, in vitro tube length, early in vivo pollen growth rate) were all positively correlated with each other, and these early characteristics were negatively correlated with late in vivo tube growth rate, which is largely influenced by the stylar genotype.
