RESUMEN
Maize has become the most widely planted crops in China and improving maize stress tolerance is one of major target traits for maize breeding. C2H2 zinc finger proteins are widely involved in growth development and stress response in plants. In this study, the transcription factor ZmC2H2-1 gene was isolated from maize and its function was investigated. Our data showed that ZmC2H2-1 belonged to C2H2 transcription factor family, mainly located in the nucleus, and cannot self-activate in yeast. Drought, salt and ABA can inhibit ZmC2H2-1 expression in maize. The water loss rate of excised-leaves was faster in ZmC2H2-1-transgenic Arabidopsis than that in WT. When treated with PEG, high salt and ABA, the stress tolerance was more sensitive in ZmC2H2-1-transgenicplants than WT. These data showed that ZmC2H2-1 played a negative role in stress tolerance in maize. Collectively, this study provides important information for us to analyze ZmC2H2-1 regulatory network and mechanism of stress tolerance in maize.
Asunto(s)
Proteínas de Plantas/metabolismo , Factores de Transcripción/metabolismo , Zea mays/fisiología , Arabidopsis/genética , Arabidopsis/fisiología , Dedos de Zinc CYS2-HIS2 , Regulación de la Expresión Génica de las Plantas , Proteínas de Plantas/genética , Plantas Modificadas Genéticamente/metabolismo , Plantas Modificadas Genéticamente/fisiología , Tolerancia a la Sal , Cloruro de Sodio , Estrés Fisiológico , Factores de Transcripción/genética , Zea mays/genéticaRESUMEN
Plant microRNAs (miRNAs) are a class of small non-coding RNAs which target and regulate the expression of genes involved in several growth, development, and metabolism processes. The miR169 family is the largest and most conserved miRNA family in plants. Recent researches have shown involvement of miR169 members in the regulation of plant responding to abiotic stress and development. Computational prediction and experimental analyses suggest that miR169 targets members of the transcription factor NF-YA gene family. In this review, we summarize the origins, evolution and diversity of miR169 family members. In addition, a comprehensive understanding the regulatory functions of the miR169/NF-YA module in plant with particular emphasis on stress-induced flowering is discussed.
Asunto(s)
Regulación de la Expresión Génica de las Plantas/genética , Genes de Plantas/genética , MicroARNs/genética , ARN de Planta/genética , Factores de Transcripción/genética , Flores/genética , Estrés Fisiológico/genéticaRESUMEN
Plants interact with their environment and they often flower earlier under stress conditions, but how such stress-induced flowering is regulated remains poorly understood. Here evidence is presented that the miR169 family plays a key role in stress-induced flowering in plants. The microRNA (miRNA) miR169 family members are up-regulated in Arabidopsis, maize, and soybean under abiotic stresses. Overexpression of miR169d in Arabidopsis results in early flowering, and overexpression of the miR169d target gene, AtNF-YA2, especially a miR169d-resistant version of AtNF-YA2, results in late flowering. The results suggest that the miR169 family regulates stress-induced flowering by repressing the AtNF-YA transcription factor, which in turn reduces the expression of FLOWERING LOCUS C (FLC), allowing for the expression of FLC target genes such as FLOWERING LOCUS T (FT) and LEAFY (LFY) to promote flowering. It was shown that the expression of genes or miRNAs involved in the other flowering pathways, namely the photoperiod (CO), ambient temperature (SVP), ageing (miR156), and gibberelin (SOC1) pathways, was not affected in miR169d-overexpressing plants, suggesting that stress-induced early flowering is a novel signalling pathway mediated by miR169.
Asunto(s)
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Flores/genética , Regulación de la Expresión Génica de las Plantas , MicroARNs/genética , Transducción de Señal , Arabidopsis/fisiología , Proteínas de Arabidopsis/metabolismo , Factor de Unión a CCAAT/genética , Inmunoprecipitación de Cromatina , Frío , Flores/fisiología , Proteínas de Dominio MADS/genética , Proteínas de Dominio MADS/metabolismo , Modelos Biológicos , Fotoperiodo , Hojas de la Planta/genética , Hojas de la Planta/fisiología , Plantas Modificadas Genéticamente , Regiones Promotoras Genéticas , ARN de Planta/genética , Estrés Fisiológico , Factores de Tiempo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Regulación hacia ArribaRESUMEN
Scaffold/matrix attachment regions (S/MARs) are defined as genomic DNA sequences, located at the physical boundaries of chromatin loops. Previous reports suggest that S/MARs elements may increase and stabilize the expression of transgene. In this study, DNA sequence with MAR characteristics has been isolated from B. napus . The BnMARs sequence was used to flank the CaMV35S-GUS-NOS expression cassette within the T-DNA of the plant expression vector pPZP212. These constructs were introduced into tobacco plants, respectively and the GUS reporter gene expression was investigated in stably transformed plants. When the forward BnMARs sequence was inserted into the upstream of CaMV35S promoter, the average GUS activities were much higher than those without BnMARs in transgenic tobacco. The GUS expression of M(+)35S:GUS, M(+)35S:GUSM(+) and M(+)35S:GUSM(-) constructs increased average 1.0-fold, with or without BnMARs located downstream of NOS. The GUS expression would not be affected when reverse BnMARs sequence inserted whether upstream of CaMV35S promoter or downstream of NOS. The GUS expression was affected a little when reverse BnMARs sequence was inserted the downstream of NOS and BnMARs could not act by serving as of promoter. The results showed that the presence of forward BnMARs sequence does have an obvious impact on enhancing downstream gene expression and its effect is unidirectional.