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Mol Plant ; 7(4): 616-25, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24157606


PHYTOCHROME INTERACTING FACTOR3 (PIF3) is an important component in the phytochrome signaling pathway and mediates plant responses to various environmental conditions. We found that PIF3 is involved in the inhibition of root growth of Arabidopsis thaliana seedlings induced by nitric oxide (NO) in light. Overexpression of PIF3 partially alleviated the inhibitory effect of NO on root growth, whereas the pif3-1 mutant displayed enhanced sensitivity to NO in terms of root growth. During phytochrome signaling, the photoreceptor PHYB mediates the degradation of PIF3. We found that the phyB-9 mutant had a similar phenotype to that of PIF3ox in terms of responsiveness to NO. Furthermore, NO treatment promoted the accumulation of PHYB, and thus reduced PIF3 content. Our results further show that the activity of PIF3 is regulated by the DELLA protein RGL3[RGA (repressor of ga1-3) LIKE 3]. Therefore, we speculate that PIF3 lies downstream of PHYB and RGL3, and plays an important role in the inhibitory effect of NO on root growth of Arabidopsis seedlings in light.

Proteínas de Arabidopsis/metabolismo , Arabidopsis/efeitos dos fármacos , Arabidopsis/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Luz , Óxido Nítrico/farmacologia , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Proteínas de Arabidopsis/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Fitocromo B/genética , Fitocromo B/metabolismo
Nitric Oxide ; 26(1): 54-60, 2012 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-22197746


Nitric oxide (NO) participates in the regulation of diverse functions in plant cells. However, different NO concentrations may trigger different pathways during the plant development. At basal levels of NO, plants utilize the NO signaling transduction pathway to facilitate plant growth and development, whereas higher concentrations trigger programmed cell death (PCD). Our results show that NO lower than the levels causing PCD, but higher than the basal levels induce DNA damage in root cells in Arabidopsis as witnessed by a reduction in root growth, rather than cell death, since cells retain the capacity to differentiate root hairs. The decrease in meristematic cells and increase in DNA damage signals in roots in responses to NO are in a dose dependent manner. The restraint of root growth is due to cell cycle arrest at G1 phase which is caused by NO induced DNA damage, besides a second arrest at G2/M existed in NO supersensitive mutant cue1. The results indicate that NO restrain root growth via DNA damage induced cell cycle arrest.

Arabidopsis/citologia , Arabidopsis/genética , Dano ao DNA , Óxido Nítrico/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Arabidopsis/crescimento & desenvolvimento , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/genética , Morte Celular/efeitos dos fármacos , Morte Celular/genética , Relação Dose-Resposta a Droga , Regulação da Expressão Gênica de Plantas , Meristema/genética , Mutação , Óxido Nítrico/farmacologia , Doadores de Óxido Nítrico/farmacologia , Nitroprussiato/farmacologia , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/genética
J Agric Food Chem ; 58(15): 8490-4, 2010 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-20614904


As more and more genetically modified organisms (GMO) are commercialized, efficient and inexpensive assays are required for their quick detection. An event-specific detection strategy based on the unique and specific sequences of integration junctions is useful because of its high specificity. This study developed a system for detecting six GM maize lines (Bt11, Bt176, GA21, MON810, NK603, and T25) using optical silicon thin-film biosensor chips. Aldehyde-labeled probes were arrayed and covalently attached to a hydrazine-derivatized chip surface. Biotinylated PCR amplicons were then hybridized with the probes. After washing and brief incubation with an anti-biotin IgG horseradish peroxidase conjugate and a precipitable horseradish peroxidase substrate, biotinylated PCR amplicons perfectly matched with the probes can be visualized by the color change on the chip surface (gold to blue/purple). This assay is extremely robust, exhibits high sensitivity and specificity, and is flexible from low through moderate to high throughput.

Técnicas Biossensoriais/métodos , Plantas Geneticamente Modificadas/genética , Zea mays/genética , Técnicas Biossensoriais/instrumentação
J Genet Genomics ; 37(5): 341-6, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20513635


mRNA quantification is very important in molecular biological researches. Traditional spectrophotometric method cannot distinguish DNA, rRNA and tRNA species from mRNA. Northern blot can be used for mRNA quantification but is known to be time consuming. To rapidly detect mRNA levels, we developed an optical thin-film biosensor chip based method, to quantify mRNA in samples. After total RNA was extracted, the mRNA with poly(A) tails was reverse transcribed with oligo(dT)(20) primers and dNTPs mixed with digoxigenin(DIG)-11-dUTP. The transcribed first strand cDNA was hybridized with oligo(dA)(20) nucleotide probes spotted on optical thin-film biosensor chips. Excess first strand cDNA, single-strand RNA, and mis-matched DNA/DNA hybrids were removed by washing. The perfect-matched DNA/DNA hybrid was detected with anti-DIG-AP (alkaline phosphatase) conjugate and then incubated with NBT/BCIP substrate for color development. The range of the color is from purplish red to blue, according to the cDNA mass deposited on chip surface. Detection of mRNA levels from Arabidopsis samples proved that this method is feasible for mRNA quantification, and has great potential for application in mRNA quantification in various organisms.

Arabidopsis/química , Técnicas Biossensoriais/métodos , Análise de Sequência com Séries de Oligonucleotídeos/métodos , RNA Mensageiro/análise , RNA de Plantas/análise , Arabidopsis/genética , RNA Mensageiro/genética , RNA de Plantas/genética
Appl Microbiol Biotechnol ; 86(3): 983-90, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20091028


Traditional methods for identifying food-borne pathogens are time-consuming and laborious, so it is necessary to develop innovative methods for the rapid identification of food-borne pathogens. Here, we report the development of silicon-based optical thin-film biosensor chips for sensitive detection of 11 food-borne pathogens. Briefly, aldehyde-labeled probes were arrayed and covalently attached to a hydrazine-derivatized chip surface, and then, biotinylated polymerase chain reaction (PCR) amplicons were hybridized with the probes. After washing and brief incubation with an antibiotin immunoglobulin G-horseradish peroxidase conjugate and a precipitable horseradish peroxidase substrate, biotinylated chains bound to the probes were visualized as a color change on the chip surface (gold to blue/purple). Highly sensitive and accurate examination of PCR fragment targets can be completed within 30 min. This assay is extremely robust, sensitive, specific, and economical and can be adapted to different throughputs. Thus, a rapid, sensitive, and reliable technique for detecting 11 food-borne pathogens was successfully developed.

Bactérias/isolamento & purificação , Técnicas Biossensoriais/métodos , Microbiologia de Alimentos , Análise em Microsséries/métodos , Reação em Cadeia da Polimerase/métodos , Bactérias/genética , Humanos , Sensibilidade e Especificidade