RESUMO
To understand the function of vernalization-related gene VER17 in winter wheat (Triticum aestivum L. cv. Jingdong No.1), an antisense RNA strategy was used. The antisense VER17 with a vector pBI121 was constructed and transformed into winter wheat by using the pollen-tube-pathway method. Fourteen independent transgenic plants transformed with antisense VER17 and five control transformants transformed with pBI121 blank vector were obtained and confirmed by GUS histochemical assay and PCR-Southern blot analysis. Phenotypes of T(0) and T(1) transgenic plants showed that the plants of the antisense VER17 transgenic lines degenerated top or basal spikelets and had delayed flowering time, which suggested that the VER17 gene functions in accelerating flowering and the development of the top or basal spikelets and the stamen which were impacted by vernalization treatment.
Assuntos
Flores/genética , Proteínas de Plantas/genética , RNA Antissenso/genética , Triticum/genética , Southern Blotting , Flores/crescimento & desenvolvimento , Flores/metabolismo , Regulação da Expressão Gênica de Plantas , Glucuronidase/genética , Glucuronidase/metabolismo , Proteínas de Plantas/metabolismo , Proteínas de Plantas/fisiologia , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Plantas Geneticamente Modificadas/metabolismo , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Estações do Ano , Transformação Genética , Triticum/crescimento & desenvolvimento , Triticum/metabolismoRESUMO
A vernalization-related gene VER2 was isolated from winter wheat ( Triticum aestivum L.) using a differential screening approach. The deduced VER2 is a lectin-like protein of 300 amino acids, which contains the presence of a jacalin-like GWG domain. RNA in situ hybridization results demonstrated that VER2 gene expression is restricted to the marginal meristems of immature leaves in vernalized wheat seedlings. No hybridization signal was detected in the epidermal tissue and vascular bundles. However, "devernalization" resulted in the silencing of VER2 gene activity. The gene expression pattern of VER2 induced by jasmonate was similar to that induced by vernalization. Antisense inhibition of VER2 in transgenic wheat showed that heading and maturation time were delayed up to 6 weeks compared with non-transformed wheat and the pBI121empty-vector-transformed wheat. Tissue degeneration at the top of the spike was also noticed in the antisense inhibited transgenic wheat. These results suggest that VER2 plays an important role in vernalization signaling and spike development in winter wheat.
Assuntos
Flores/genética , Flores/fisiologia , Genes de Plantas/genética , Triticum/genética , Triticum/fisiologia , Sequência de Aminoácidos , Sequência de Bases , Clonagem Molecular , Regulação da Expressão Gênica de Plantas , Hibridização In Situ , Dados de Sequência Molecular , Fenótipo , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas , RNA de Plantas/análise , RNA de Plantas/genética , Estações do Ano , Alinhamento de SequênciaRESUMO
The function of ver203, a gene related to vernalization in winter wheat, was investigated by expression of a complementary DNA as an antisense RNA in transgenic plants. A verc203:gus fusion-expression plasmid was constructed in pBI221, which contains a CaMV (cauliflower mosaic virus) 35S-promoter, a gus gene and a nos terminator. The construct was then introduced into the plant by the pollen-tube pathway. The results showed that heading was strongly inhibited in 6 of 326 vernalized antisense transgenic winter wheat plants, until both the vernalized control winter wheat and sense transgenic plants ripened. The hybridization analysis of DNA, amplification of the insert DNA sequences with PCR, northern blot analysis with double- and single-stranded probes, and detection of GUS activity by X-gluc assay gave strong positive results. This suggests that the VER203 protein plays an important role in controlling heading and flower development in winter wheat.
