RESUMO
Glyphosate is a broad spectrum, non-selective herbicide which has been widely used for weed control. Much work has focused on elucidating the high accumulation of glyphosate in shoot apical bud (shoot apex). However, to date little is known about the molecular mechanisms of the sensitivity of shoot apical bud to glyphosate. Global gene expression profiling of the soybean apical bud response to glyphosate treatment was performed in this study. The results revealed that the glyphosate inhibited tryptophan biosynthesis of the shikimic acid pathway in the soybean apical bud, which was the target site of glyphosate. Glyphosate inhibited the expression of most of the target herbicide site genes. The promoter sequence analysis of key target genes revealed that light responsive elements were important regulators in glyphosate induction. These results will facilitate further studies of cloning genes and molecular mechanisms of glyphosate on soybean shoot apical bud.
Assuntos
Regulação da Expressão Gênica de Plantas , Glycine max/genética , Glicina/análogos & derivados , Brotos de Planta/efeitos dos fármacos , Perfilação da Expressão Gênica , Glicina/farmacologia , Herbicidas/farmacologia , Luz , Regiões Promotoras Genéticas , Ácido Chiquímico/metabolismo , Glycine max/efeitos dos fármacos , Triptofano/biossíntese , GlifosatoRESUMO
Three new dammarane-type glycosides, named ginsenosides SL(1)-SL(3) (1-3), and eleven known compounds (4-14) were isolated from the heat-processed leaves of Panax ginseng. Their structures were elucidated on the basis of extensive chemical and spectroscopic methods. Cytotoxic-activity testing of compounds 1-14 against human leukemia HL-60 cells showed that ginsenosides Rh(3) (11) and Rk(2) (12) exhibited potent effects with IC(50) values of 0.8 and 0.9 microM. In addition, ginsenosides SL(3) (3), 20S-Rg(2) (7), F(4) (10), 20S-Rh(2) (13) displayed strong activity with IC(50) values of 9.0, 9.0, 7.5, and 8.2 microM, respectively. This is the first report on chemical components of the steamed ginseng leaves.
Assuntos
Antineoplásicos/toxicidade , Ginsenosídeos/toxicidade , Panax/química , Extratos Vegetais/toxicidade , Folhas de Planta/química , Antineoplásicos/química , Antineoplásicos/isolamento & purificação , Proliferação de Células/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Ginsenosídeos/química , Ginsenosídeos/isolamento & purificação , Células HL-60 , Humanos , Concentração Inibidora 50 , Conformação Molecular , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , EstereoisomerismoRESUMO
Ethylene-responsive factors (ERFs) are important regulators of plant gene expression. In this study, three novel ERF genes, GhERF2, GhERF3 and GhERF6, were isolated from cotton (Gossypium hirstum) using rapid amplification of cDNA ends-polymerase chain reaction. Transient expression analysis using GhERF-green fluorescent protein fusions showed that these three proteins were targeted to the nucleus. Fusion proteins consisting of GhERF2, GhERF3 or GhERF6 coupled to the GAL4 DNA binding domain strongly activated transcription in yeast. Furthermore, GhERF6 was shown to be able to bind specifically to GCC boxes using a particle bombardment assay in tobacco cells. Semi-quantitative reverse transcription-polymerase chain reaction revealed that GhERF2 and GhERF3 are constitutively expressed in all organs, while GhERF6 is only constitutively expressed in vegetative organs. When plants were treated with ethylene, abscisic acid, salt, cold and drought, the transcripts of GhERF2, GhERF3 and GhERF6 were rapidly induced to high levels. Promoter analysis also indicated that the 5' upstream regions of the three genes possess elements induced by these physiological and environmental factors. Collectively, our data suggest that GhERF2, GhERF3 and GhERF6 might function as positive trans-acting factors in the plant responses to ethylene, abscisic acid and other stresses and provide useful clues for further research into the mechanism of them in regulating cotton multiple stress responses.
Assuntos
Proteínas de Ligação a DNA/genética , Genes de Plantas/genética , Gossypium/genética , Proteínas de Plantas/genética , Bioensaio , Núcleo Celular/metabolismo , Passeio de Cromossomo , DNA Complementar/genética , DNA Complementar/isolamento & purificação , Proteínas de Ligação a DNA/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Proteínas de Fluorescência Verde/metabolismo , Cebolas/citologia , Cebolas/metabolismo , Filogenia , Proteínas de Plantas/metabolismo , Regiões Promotoras Genéticas/genética , Transporte Proteico , Saccharomyces cerevisiae/citologia , Saccharomyces cerevisiae/metabolismo , Alinhamento de Sequência , Análise de Sequência de DNA , Nicotiana/citologia , Nicotiana/metabolismo , Ativação Transcricional/genéticaRESUMO
Korean ginseng (Panax ginseng C.A. Meyer) has been extensively used as a functional food for thousands of years. This study with the aim to evaluate the potential of P. ginseng flower components as a functional food with medicinal properties resulted in the identification of three new dammarane-type saponins, named floralginsenosides Ka-Kc (1-3), along with seventeen known ones (4-20). Their structures were elucidated on the basis of chemical and spectroscopic methods, and their antioxidant activities were evaluated by the intracellular ROS radical scavenging DCF-DA assay. Among them, floralginsenoside Ka (1) displayed potent scavenging activity with the inhibition value of 64% at 10 microM; and ginsenoside Rb(1) (13), floralginsenoside Kc (3), floralginsenoside Kb (2), vinaginsenoside R(9) (11), majoroside F(1) (12), ginsenoside I (17), and ginsenoside II (18) showed moderate scavenging capacity with the inhibition rate of 28, 33, 35, 35, 35, 38, and 38% at 10 microM, respectively. These results warrant further studies concerning the potential of saponin extracts of P. ginseng flowers for functional foods.