Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 7 de 7
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
BMC Plant Biol ; 19(1): 371, 2019 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-31438856

RESUMO

BACKGROUND: Propamocarb (PM) is one of the main pesticides used for controlling cucumber downy mildew. However, due to its volatility and internal absorption, PM can easily form pesticide residues on cucumber fruits that seriously endanger human health and pollute the environment. The breeding of new cucumber varieties with a low abundance of PM residues via genetic methods constitutes an effective strategy for reducing pesticide residues and improving cucumber safety and quality. To help elucidate the molecular mechanism resulting in a low PM residue abundance in cucumber, we used the cucumber cultivar 'D0351' (which has the lowest PM residue content) as the test material and identified genes related to low PM residue abundance through high-throughput tag-sequencing (Tag-Seq). RESULTS: CsMAPEG was constitutively expressed and showed both varietal and organizational differences. This gene was strongly expressed in 'D0351'. The expression levels of CsMAPEG in different cucumber tissues under PM stress were as follows: fruit>leaf>stem>root. CsMAPEG can respond to salicylic acid (SA), gibberellin (GA) and Corynespora cassiicola Wei (Cor) stress and thus plays an important regulatory role in plant responses to abiotic and biological stresses. The PM residue abundance in the fruits of CsMAPEG-overexpressing plants was lower than those found in antisense CsMAPEG plants and wild-type plants at all tested time points. The results revealed that CsMAPEG played a positive role in reducing the PM residue abundance. A CsMAPEG sense construct increased the contents of SOD, POD and GST in cucumber fruits, enhanced the degradation and metabolism of PM in cucumber, and thus effectively reduced the pesticide residue abundance in cucumber fruits. CONCLUSIONS: The expression patterns of CsMAPEG in cucumber cultivars with high and low pesticide residue abundances and a transgenic verification analysis showed that CsMAPEG can actively respond to PM stress and effectively reduce the PM residue abundance in cucumber fruits. The results of this study will help researchers further elucidate the mechanism responsible for a low PM residue abundance in cucumber and lay a foundation for the breeding of new agricultural cucumber varieties with low pesticide residue abundances.


Assuntos
Carbamatos/farmacologia , Cucumis sativus/genética , Fungicidas Industriais/farmacologia , Genes de Plantas , Resíduos de Praguicidas , Clonagem Molecular , Cucumis sativus/efeitos dos fármacos , Cucumis sativus/enzimologia , Cucumis sativus/fisiologia , Perfilação da Expressão Gênica , Vetores Genéticos , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Transformação Genética
2.
BMC Plant Biol ; 18(1): 16, 2018 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-29347906

RESUMO

BACKGROUND: Cucumber downy mildew is among the most important diseases that can disrupt cucumber production. Propamocarb, also known as propyl-[3-(dimethylamino)propyl]carbamate (PM), is a systemic carbamate fungicide pesticide that is widely applied in agricultural production because of its high efficiency of pathogens control, especially cucumber downy mildew. However, residual PM can remain in cucumbers after the disease has been controlled. To explore the molecular mechanisms of PM retention, cucumber cultivars 'D9320' (with the highest residual PM content) and 'D0351' (lowest residual PM content) were studied. High-throughput tag-sequencing (Tag-Seq) results showed that the CsDIR16 gene was related to PM residue, which was verified using transgenic technology. RESULTS: We investigated the activity of a dirigent cucumber protein encoded by the CsDIR16 in gene response to stress induced by PM treatment. Gene-expression levels of CsDIR16 were up-regulated in the fruits, leaves, and stems of 'D0351' plants in response to PM treatment. However, in cultivar 'D9320', CsDIR16 levels were down-regulated in the leaves and stems after PM treatment, with no statistically significant differences observed in the fruits. Induction by jasmonic acid, abscisic acid, polyethylene glycol 4000, NaCl, and Corynespora cassiicola Wei (Cor) resulted in CsDIR16 up-regulation in 'D0351' and 'D9320'. Expression after salicylic acid treatment was up-regulated in 'D0351', but was down-regulated in 'D9320'. CsDIR16 overexpression lowered PM residues, and these were more rapidly reduced in CsDIR16(+) transgenic 'D9320' plants than in wild-type 'D9320' and CsDIR16(-) transgenic plants. CONCLUSIONS: Analyses of the CsDIR16-expression patterns in the cucumber cultivars with the highest and lowest levels of PM residue, and transgenic validation indicated that CsDIR16 plays a positive role in reducing PM residues. The findings of this study help understand the regulatory mechanisms occurring in response to PM stress in cucumbers and in establishing the genetic basis for developing low-pesticide residue cucumber cultivars.


Assuntos
Carbamatos/metabolismo , Cucumis sativus/genética , Fungicidas Industriais/metabolismo , Oomicetos/fisiologia , Doenças das Plantas/genética , Proteínas de Plantas/genética , Sequência de Aminoácidos , Sequência de Bases , Cucumis sativus/metabolismo , Resistência à Doença/genética , Doenças das Plantas/microbiologia , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo
3.
Plant Mol Biol ; 95(4-5): 519-531, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29052099

RESUMO

KEY MESSAGE: Overexpression of CsERF025 induces fruit bending by promoting the production of ethylene. Cucumber fruit bending critically affects cucumber quality, but the mechanism that causes fruit bending remains unclear. To better understand this mechanism, we performed transcriptome analyses on tissues from the convex (C1) and concave (C2) sides of bending and straight (S) fruit at 2 days post anthesis (DPA). We identified a total of 281 differentially expressed genes (DEGs) from both the convex and concave sides of bent fruit that showed significantly different expression profiles relative to straight fruits. Of these 281 DEGs, 196 were up-regulated (C1/S_C2/S) and 85 were down-regulated (C1/S_C2/S). Among the 196 up-regulated DEGs, the transcriptional levels of genes related to ethylene biosynthesis and signaling pathways were significantly higher in bending fruit compared with straight fruit. CsERF025 showed the largest difference in expression between bending and straight fruit. CsERF025 is an AP2/ERF gene encoding a protein that localizes to the nucleus. Overexpression of this gene increased the bending rate of cucumber fruits and increased the angle of bending. CsERF025 increased both the expression of ethylene biosynthesis-related genes and the production of ethylene. The application of exogenous 1-aminocyclopropane-l-carboxylic acid (ACC) to straight fruits from control plants promoted fruit bending. Thus, CsERF025 enhances the production of ethylene and thereby promotes fruit bending in cucumber.


Assuntos
Cucumis sativus/genética , Etilenos/metabolismo , Regulação da Expressão Gênica de Plantas , Reguladores de Crescimento de Planta/metabolismo , Proteínas de Plantas/metabolismo , Transcriptoma , Cucumis sativus/crescimento & desenvolvimento , Frutas/genética , Frutas/crescimento & desenvolvimento , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Proteínas de Plantas/genética
4.
BMC Plant Biol ; 17(1): 96, 2017 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-28583084

RESUMO

BACKGROUND: Cucumber downy mildew, caused by P. cubensis, is an important leaf disease that can severely affect cucumber production. In recent years, cucumber target spot, caused by C. cassiicola, has been reported in both Asia and Europe and is now considered as a major disease disrupting cucumber production. Single-disease-resistant cucumber varieties have been unable to satisfy production needs. To explore the molecular mechanisms of cucumber resistance to these two diseases, cucumber cultivars D9320 (resistant to downy mildew and target spot) and D0401 (susceptible to downy mildew and target spot) were used as experimental materials in this study. We used transcriptome sequencing technology to identify genes related to disease resistance and verified using transgenic technology. RESULTS: We screened out the cucumber resistance-related gene CsERF004 using transcriptome sequencing technology. Induction by pathogens, salicylic acid (SA), and ethylene (ET) resulted in the up-regulation of CsERF004. Three treatments, namely, inoculation with C. cassiicola alone, inoculation with P. cubensis alone, and simultaneous inoculation with both pathogens, all resulted in the significant and sustained up-regulation of CsERF004 in the resistant cultivar D9320, during the early stage of infection. In the susceptible cultivar D0401, CsERF004 expression was also significantly up-regulated at the later stage of infection but to a lesser extent and for a shorter duration than in the resistant cultivar D9320. The CsERF004 gene encodes a protein localizes to the nucleus. The over-expression of CsERF004 in the susceptible cultivar D0401 resulted in the significant up-regulation of the CsPR1 and CsPR4 genes and increased the levels of SA and ET, which enhanced the resistance of cucumber to downy mildew and target spot. CONCLUSIONS: Analyses of the CsERF004 expression pattern in disease-resistant and susceptible cucumber cultivars and transgenic validation indicate that CsERF004 confers resistance to P. cubensis and C. cassiicola. The findings of this study can help to better understanding of mechanisms of response to pathogens and in establishment the genetic basis for the development of cucumber broad-spectrum resistant cultivars.


Assuntos
Ascomicetos/fisiologia , Cucumis sativus/genética , Resistência à Doença/genética , Oomicetos/fisiologia , Fatores de Transcrição/genética , Sequência de Aminoácidos , Cucumis sativus/metabolismo , Cucumis sativus/microbiologia , Etilenos/metabolismo , Regulação da Expressão Gênica de Plantas , Interações Hospedeiro-Patógeno/genética , Proteínas de Plantas/genética , Ácido Salicílico/metabolismo
5.
Bull Environ Contam Toxicol ; 95(1): 73-9, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25894345

RESUMO

Polycyclic musks and heavy metals are often present in natural aquatic environment. The aims of this study were to evaluate the toxic effects on Daphnia magna from exposure to the polycyclic musks and the heavy metals in combination with stress from suspended solids exposure. Galaxolide and lead were used as typical pollutants. The toxic effects on D. magna decreased with addition of suspended solids within the single experiments having galaxolide after 24 and 48 h. A similar result was observed for the toxic effect of lead on the D. magna with adding suspended solids during exposure. Synergism on D. magna was found within the combined tests having galaxolide and lead during the 24 and 48 h exposure based on additive index analysis. The combined toxic effect of galaxolide and lead was significantly decreased by adding suspended solids. The results could provide useful information for the toxic risks assessments of surface aquatic systems.


Assuntos
Benzopiranos/toxicidade , Daphnia/efeitos dos fármacos , Chumbo/toxicidade , Poluentes Químicos da Água/toxicidade , Adsorção , Animais , Cromatografia Gasosa-Espectrometria de Massas , Hidrocarbonetos/química , Modelos Teóricos , Solventes , Espectrofotometria Atômica
6.
J Plant Physiol ; 167(11): 905-13, 2010 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-20303197

RESUMO

Cucumber has been widely studied as a model for floral sex determination. In this investigation, we performed genome-wide transcriptional profiling of apical tissue of a gynoecious mutant (Csg-G) and the monoecious wild-type (Csg-M) of cucumber in an attempt to isolate genes involved in sex determination, using the Solexa technology. The profiling analysis revealed numerous changes in gene expression attributable to the mutation, which resulted in the down-regulation of 600 genes and the up-regulation of 143 genes. The Solexa data were confirmed by reverse transcription polymerase chain reaction (RT-PCR) and real-time quantitative RT-PCR (qRT-PCR). Gene ontology (GO) analysis revealed that the differentially expressed genes were mainly involved in biogenesis, transport and organization of cellular component, macromolecular and cellular biosynthesis, localization, establishment of localization, translation and other processes. Furthermore, the expression of some of these genes depended upon the tissue and the developmental stage of the flowers of gynoecious mutant. The results of this study suggest two important concepts, which govern sex determination in cucumber. First, the differential expression of genes involved in plant hormone signaling pathways, such as ACS, Asr1, CsIAA2, CS-AUX1 and TLP, indicate that phytohormones and their crosstalk might play a critical role in the sex determination. Second, the regulation of some transcription factors, including EREBP-9, may also be involved in this developmental process.


Assuntos
Cucumis sativus/genética , Cucumis sativus/metabolismo , Flores/genética , Flores/fisiologia , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Processos de Determinação Sexual , Proteínas de Plantas/genética , Proteínas de Plantas/fisiologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais/genética , Transdução de Sinais/fisiologia
7.
Ying Yong Sheng Tai Xue Bao ; 16(5): 915-8, 2005 May.
Artigo em Chinês | MEDLINE | ID: mdl-16110671

RESUMO

With substrate culture, this paper studied the effects of different concentrations of cinnamic acid on the physiological characteristics of Cucumis sativus seedling. The results showed that 25 micromol.L(-1) of cinnamic acid had an inhibition effect on carotenoids, but a promotion effect on chlorophyll a and b. 50 micromol.L(-1) of this compound could significantly inhibit the photosynthetic rate, transpiration rate and root activity (P < 0.05), and this effect was getting stronger when the concentration was higher. 150 micromol cinnamic acid.L(-1) had a significant inhibition effect on chlorophyll a and b (P < 0.05). Cinnamic acid had a weak inhibition effect on root activity when its concentration was low (25-50 micromol.L(-1)), but the effect was significant when the concentration was high (100-150 micromol.L(-1)), which became stronger with the longer handling time (P < 0.05).


Assuntos
Cinamatos/farmacologia , Cucumis sativus/crescimento & desenvolvimento , Fotossíntese/efeitos dos fármacos , Plântula/fisiologia , Carotenoides/metabolismo , Clorofila/metabolismo , Cucumis sativus/fisiologia , Transpiração Vegetal/efeitos dos fármacos , Plântula/crescimento & desenvolvimento
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA