RESUMO
NAC transcription factors are a family of functionally diverse proteins. They are unique to plants and play an important role in regulation of plant growth and development, hormone regulation and responses to various stresses. A cDNA encoding the NAC-like gene homologue was isolated from maize (Zea mays L.) by RT-PCR and designated ZmNAC1 (GenBank Accession No. EU224278). Sequence analysis showed that cDNA of ZmNAC1 was 1,029 bp long and contained a single open reading frame (ORF, 26 to approximately 907 bp). The predicted ZmNAC1 protein has 293 amino acids with an estimated molecular mass of 32.3 kDa and an isoelectric point of 8.65. RT-PCR analysis showed that the expression of ZmNAC1 was induced by low temperature, PEG, salt, and ABA, respectively. These results suggest that ZmNAC1 may play important roles in biotic and abiotic resistance pathways. This is the first NAC-like gene reported in maize.
Assuntos
Regulação da Expressão Gênica de Plantas , Fatores de Transcrição/genética , Zea mays/genética , Sequência de Aminoácidos , Proteínas de Arabidopsis , Sequência de Bases , Clonagem Molecular , DNA Complementar/análise , DNA Complementar/química , Dados de Sequência Molecular , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Alinhamento de Sequência , Transativadores , Fatores de Transcrição/metabolismo , Zea mays/metabolismoRESUMO
NAC genes, specific to plants, play important roles in plant development as well as in response to biotic and abiotic stresses. Here, a novel gene encoding a NAC domain, named as GhSNAC3, was isolated from upland cotton (Gossypium hirsutum L.). Sequence analyses showed that GhSNAC3 encodes a protein of 346 amino acids with an estimated molecular mass of 38.4 kDa and pI of 8.87. Transient localization assays in onion epidermal cells confirmed GhSNAC3 is a nuclear protein. Transactivation studies using a yeast system revealed that GhSNAC3 functions as a transcription activator. Quantitative real-time polymerase chain reaction analysis indicated that GhSNAC3 was induced by high salinity, drought and abscisic acid treatments. We overexpressed GhSNAC3 in tobacco by using Agrobacterium-mediated transformation. Transgenic lines produced longer primary roots and more fresh weight under salt and drought stresses as compared to wild-type plants. Collectively, our results indicated that overexpression of GhSNAC3 in tobacco can enhance drought and salt tolerances.
Assuntos
Regulação da Expressão Gênica de Plantas/genética , Gossypium/genética , Proteínas Nucleares/genética , Proteínas de Plantas/genética , Ácido Abscísico/farmacologia , Sequência de Aminoácidos , Sequência de Bases , Secas , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Reguladores de Crescimento de Plantas/farmacologia , Plantas Geneticamente Modificadas , Salinidade , Tolerância ao Sal/genética , Homologia de Sequência de Aminoácidos , Homologia de Sequência do Ácido Nucleico , Nicotiana/genéticaRESUMO
Microsatellites, or simple sequence repeats (SSRs), in expressed sequence tags (ESTs) provide an opportunity for low cost SSR development. We looked for EST-SSRs in 403,511 ESTs (generated by 454 sequencing and representing 70,654 contigs and 52,082 singletons) from soybean globular stage embryos. Among 122,736 unique ESTs, 3,729 contained one or more SSRs. In total, 3,989 SSRs were identified including 304 mono, 1,374 di, 2,208 tri, 70 tetra, 13 penta and 20 hexanucleotide SSRs. Thirty three EST-SSRs were selected for primer design and polymorphism analysis using twenty soybean cultivars and one wild-type soybean. Successful amplification was obtained using 21 of these primer pairs, 11 of which detected polymorphisms in these soybean cultivars. These results demonstrated that 454 high throughput sequencing is a powerful tool for molecular marker development. From the 3,989 identified SSRs we expect to obtain a large number of makers with polymorphism among different soybean cultivars, which would be useful for analysis of genetic diversity and maker assisted selection in the soybean breeding programs.