Powdery mildew is one of the most devastating diseases in cucurbits. Crop yield can decline as the disease severity increases. In this study, we evaluated the effect of silver nanoparticles against powdery mildew under different cultivation conditions in vitro and in vivo . Silver nanoparticles (WA-CV-WA13B) at various concentrations were applied before and after disease outbreak in plants to determine antifungal activities. In the field tests, the application of 100 ppm silver nanoparticles showed the highest inhibition rate for both before and after the outbreak of disease on cucumbers and pumpkins. Also, the application of 100 ppm silver nanoparticles showed maximum inhibition for the growth of fungal hyphae and conidial germination in in vivo tests. Scanning electron microscope results indicated that the silver nanoparticles caused detrimental effects on both mycelial growth and conidial germination.
Cucumis sativus ; Cucurbita ; Disease Outbreaks ; Electrons ; Germination ; Hyphae ; Nanoparticles ; Silver

The cultivation and production of cucumber are seriously affected by downy mildew caused by Pseudoperonospora cubensis. Downy mildew damages leaves, stems and inflorescences, and then reduces the yield and quality of cucumber. This review summarized the research advances in cucumber downy mildew, including pathogen detection and defense pathways, regulatory factors, mining of pathogens-resistant candidate genes, proteomic and genomic analysis, and development of QTL remarks. This review may facilitate clarifying the resistance mechanisms of cucumber to downy mildew.
Cucumis sativus/genetics* ; Oomycetes/genetics* ; Peronospora ; Plant Diseases/genetics* ; Proteomics

OBJECTIVETo study the chemical constituents contained in the seeds of Cucumis sativus.

METHODThe fatty oil was extracted by heating and refluxing with petroleum ether. Potassium hydroxide-methanol solution was used for saponification. An unsaponifiable matter was extracted by EtOAc and separated with various chromatographic methods. Its structure was identified on the basis of their physicochemical properties and spectral data. The fatty acid fraction was methyl-esterified and determined by GC. The composition and relative content of fatty acid were determined with normalization method of peak area.

RESULT24-ethylcholesta-7, 22, 25-trienol (1), 24-ethylcholesta-7, 25-dienol (2) ,avenasterol (3), spinasterol (4), karounidiol (5) and isokarounidiol (6) were separated and identified from the unsaponifiable matter. Myristic acid (7, 0.12%), palmitic acid (8, 12.04%), palmitoleic acid (9, 0.09%), heptadecanoic acid (10, 0.06%), stearic acid (11, 5.64%), oleic acid (12, 6.95%), linoleic acid (13, 74.40%), arachidic acid (14, 0.19%), and alpha-linolenic acid (15, 0.51%) were identified from the fatty acids part.

CONCLUSIONCompounds 5, 6, 9, 10, 14,and 15 were first reported in C. sativus.

Cucumber (Cucumis sativus) is an important vegetable crop in the world. Agrobacterium-mediated transgenic technology is an important way to study plant gene functions and improve varieties. In order to further accelerate the transgenic research and breeding process of cucumber, we described the progress and problems of Agrobacterium tumefaciens-mediated transgenic cucumber, from the influencing factors of cucumber regeneration ability, genetic transformation conditions and various additives in the process. We prospected for improving the genetic transformation efficiency and safety selection markers of cucumber, and hoped to provide reference for the research of cucumber resistance breeding and quality improvement.
Agrobacterium tumefaciens ; metabolism ; Breeding ; Cucumis sativus ; genetics ; microbiology ; Plants, Genetically Modified ; microbiology ; Research ; Transformation, Genetic

Hairy roots of Cucumis sativus L. could be incited directly from the cut edges of 10-day-old cotyledon explants after infection with the strain Agrobacterium rhizogenes ATCC15834 harboring agropine-type plasmid, pRiA4b for 5 days. It was observed that the percentage of rooting cotyledon explants was more than 90 % 10 days after infection. Hairy roots could grow rapidly and highly branched on solid plant growth regulator-free MS medium. The PCR amplification of rol B genes and vir C gene showed that T-DNA of Ri plasmid of A. rhizogenes was integrated and expressed into the genome of transformed cucumber hairy roots. A bacterium-free transformed cucumber hairy root line was selected to culture on solid MS medium to examine influence of exogenous cytokinin 6-BA on growth and morphology alteration of cucumber hairy roots. The results showed that cytokinin 6-BA can influence the growth and altered the morphology of hairy roots. With increasing of 6-BA concentrations, Cucumber hairy roots become shorter and thicker and less branched. 6-BA at the concentration of 0.1 to approximately 3.0 mg/L could delay the appearance of maximum growth peak by 5 days and decreased the content of soluble protein, enhanced the activities of SOD and POD and decreased the levels of endogenous ethylene evolution in cucumber hairy roots. Our results also indicated that cytokinin 6-BA in the medium could influence growth and morphology alternation of cucumber hairy roots and delay its senescence of hairy roots by acting through ethylene.
Cucumis sativus ; genetics ; growth & development ; Culture Media ; Culture Techniques ; Cytokinins ; pharmacology ; Plant Growth Regulators ; pharmacology ; Plant Roots ; genetics ; growth & development ; Rhizobium ; genetics ; Transfection ; Transformation, Genetic

Effects of phosphorus deficiency in the medium on growth and morphology and activities of SOD and POD, utilization of nitrogen and calcium in the medium during liquid culture of Cucumis sativus hairy roots were investigated. The results showed that C. sativus hairy roots can not grow in the medium without addition of any phosphorus. When cultured into the medium with different Pi concentrations, the growth of C. sativus hairy roots was significantly inhibited with the decreasing of Pi concentration in the medium, its main roots became thinner and longer, the number of its lateral roots was decreased and its lateral roots became shorter and smaller. Compared to the medium with full strength phosphorus, the content of soluble proteins in C. sativus hairy roots cultured under Pi deficiency was significantly lower than that with standard full-length Pi, while POD and SOD activities in C. sativus hairy roots were significantly stimulated. Compared to the control (without addition of any phosphorus in the medium), the activities of POD and SOD in C. sativus hairy roots cultured in the medium with different concentration of Pi were lower than the control. When C. sativus hairy roots were cultured into medium with different Pi concentrations, the medium conductivity was gradually decreased with time and with direct proportion of the initial Pi concentration of the medium; NH4(+)-N and NO3(-)-N of the medium was gradually absorbed and utilized, at day 15, NH4(+)-N of the medium was nearly used up but its NO3(-)-N was not used up until cultured for 30 days. Pi deficiency in the medium could decrease the consumption rate of NO3(-)-N and inhibited the absorption and utilization of calcium of the medium by C. sativus hairy roots. Proper enhancement of Pi concentration could stimulate absorption and consumption of calcium of the medium.
Calcium ; metabolism ; Cucumis sativus ; growth & development ; metabolism ; Culture Media ; Nitrogen ; metabolism ; Phosphates ; pharmacology ; Plant Roots ; growth & development ; metabolism ; Superoxide Dismutase ; metabolism ; Tissue Culture Techniques

The effects of heavy metal cadmium (Cd), alone and in combination with zinc (Zn), on the root growth and activity of antioxidant enzymes superoxide dismutase (SOD) and peroxidase (POD) in Cucumis sativus L. hairy roots were studied. The purpose was to study the possibilities on using C. sativus hairy roots for phytoremediation of cadmium contamination. The results showed that less than 10 mg/L Cd enhanced the growth of C. sativus hairy roots and increased root diameter only in 5-15 days of root culture. At Cd concentrations above 15 mg/L hairy root growth was gradually inhibited with increasing Cd concentration. The roots formed were shorter with smaller lateral roots. Among all the Cd concentrations tested, except with 10 mg/L Cd, the soluble protein contents in the C. sativus hairy roots cultured with the other Cd concentrations decreased, but the POD and SOD activities increased gradually with time during the culture process. Further tests were conducted using a control culture containing 25 mg/L Zn alone. The addition of 1 mg/L Cd to the 25 mg/L Zn culture stimulated the growth of C. sativus hairy roots after 7-15 days of growth, compared with the control. At all other Cd concentrations the growth of C. sativus hairy roots was inhibited compared to the control. Growth inhibition increased with increasing Cd concentration, and the hairy roots formed fewer, shorter and smaller lateral roots, the tips of which became swollen. After 5 days culture with different concentrations of Cd + 25 mg/L Zn, the root biomass and the activity of POD and SOD were lower than in C. sativus hairy roots cultured without the addition of Zn. However, the soluble protein content was significantly higher when the culture contained 25 mg/L Zn. Our results suggested that C. sativus hairy roots have higher tolerance to heavy metal Cd but higher concentration of Cd inhibited the growth. Cd in combination with Zn would result in more serious Cd-induced growth inhibition.
Biodegradation, Environmental ; Cadmium ; pharmacology ; Cucumis sativus ; enzymology ; growth & development ; Peroxidase ; metabolism ; Plant Roots ; enzymology ; growth & development ; Superoxide Dismutase ; metabolism ; Tissue Culture Techniques ; Zinc ; pharmacology

This study was carried out to compare bone density risk factors affecting women's BMD, and to examine the relationship age, lifestyle and dietary habits for bone health by physical measurement and questionnaires. The subjects of this study were 194 women living in the Seoul area. When the subjects were divided into normal and risk groups, BMD, height, weight, BMI, total body water, soft lean mass, fat free mass, protein, mineral, body-fat of normal group were much higher than those of the risk group. The breakfast eating rate of the normal group was much higher than that of the risk group, walking time was significantly longer and exercise was more (p < 0.05). The normal group had more frequent intakes of tunas, squid, radishes, the green parts of radish, cucumbers, carrots and Iucchinis, tomatoes, and grapes than the risk group (p < 0.01 or p < 0.05). In conclusion, breakfast eating, exercise, intakes of some foods such as anchovies, radishes, carrots, zucchinis and tomatoes were significantly important factor to prevent bone density risk.
Body Water ; Bone Density ; Breakfast ; Cucumis sativus ; Daucus carota ; Decapodiformes ; Female ; Food Habits ; Humans ; Life Style ; Lycopersicon esculentum ; Raphanus ; Risk Factors ; Tuna ; Vitis ; Walking

Soil archaea and fungi play important roles in the greenhouse soil ecosystem. To develop and apply rich microbial resources in greenhouse ecological environment, and to understand the interaction between microbes and plants, we constructed archaeal 16S rRNA and fungal 18S rRNA gene libraries to analyze the compositions of archaeal and fungal communities. Total greenhouse soil DNA was directly extracted and purified by skiving-thawing-lysozyme-proteinase K-SDS hot treatment and treatment of cetyltriethylammnonium bromide (CTAB). After PCR amplification, retrieving, ligating, transforming, screening of white clones, archaeal 16S rRNA and fungal 18S rRNA gene libraries were constructed. The sequences of archaea and fungi were defined into operational taxonomic units (OTUs) when 97% similarity threshold for OTU assignment was performed by using the software DOTUR. Phylogenetic analysis showed that crenarchaeota and unidentified-archaea were the two major sub-groups and only a few of euryarchaeota existed in the archaeal clone library, total 45 OTUs. All the crenarchaeota belonged to thermoprotei; except for Basidiomycotina, the other four sub-group fungi were discovered in the fungal library, total 24 OTUs. The diversities of archaea were very abundant and a few euryarchaeota (methanebacteria) existed in the archaeal clone library, it might be directly related to the long-term high temperature, high humidity, and high content of organic matter. The limitation of oxygen was the other reason for causing this phenomenon; Ascomycotina (over 80%) was the dominant sub-groups in fungal library. It was because most of the plant fungal diseases belonged to soil-borne diseases which gone through the winter by the ways of scierotium or perithecium and became the sources of primary infection.
Archaea ; genetics ; growth & development ; Biodiversity ; Cloning, Molecular ; Cucumis sativus ; growth & development ; Fungi ; genetics ; growth & development ; Gene Library ; Genes, rRNA ; Microclimate ; Phylogeny ; Plant Roots ; microbiology ; RNA, Archaeal ; genetics ; RNA, Fungal ; genetics ; RNA, Ribosomal, 16S ; genetics ; RNA, Ribosomal, 18S ; genetics ; Soil Microbiology

The replicase genes of five isolates of Cucumber green mottle mosaic virus from Jiangsu, Zhejiang, Hunan and Beijing were amplificated, sequenced and analyzed. The similarities of nucleotide acid sequences indicated that 129 kD and 57 kD replicase genes of CGMMV-No. 1, CGMMV-No. 2, CGMMV-No. 3, CGMMV-No. 4 and CGMMV-No. 5 were 99.64% and 99.74%, respectively. The similarities of 129 kD and 57 kD replicase genes of CGMMV-No. 1, CGMMV-No. 3 and CGMMV-No. 4 were 99.95% and 99.94%, while they were lower between CGMMV-No. 2 and the rest of four reference sequences, just from 99.16% to 99.27% and from 99.04% to 99.18%. All reference sequences could be divided into six groups in neighbor-joining (NJ) phylogenetic trees based on the replicase gene sequences of 129 kD, 57 kD protein respectively. CGMMV-No. 1, CGMMV-No. 3 and CGMMV-No. 4 were clustered together with Shandong isolate (Accession No. KJ754195) in two NJ trees; CGMMV-No. 5 was clustered together with Liaoning isolate (Accession No. EF611826) in two NJ trees; CGMMV-No. 2 was clustered together with Korea watermelon isolate (Accession No. AF417242) in phylogenetic tree of 129 kD replicase gene of CGMMV; Interestingly, CGMMV-No. 2 was classified as a independent group in phylogenetic tree of 57 kD replicase gene of CGMMV. There were no significant hydrophobic and highly coiled coil regions on 129 kD and 57 kD proteins of tested CGMMV isolates. Except 129 kD protein of CGMMV-No. 4, the rest were unstable protein. The number of transmembrane helical segments (TMHs) of 129 kD protein of CGMMV-No. 1, CGMMV-No. 2, CGMMV-No. 3 and CGMMV-No. 5 were 6, 6, 2 and 4, respectively, which were 13, 13 and 5 on the 57 kD protein of CGMMV-No. 2, CGMMV-No. 4 and CGMMV-No. 5. The glycosylation site of 129 kD protein of tested CGMMV isolates were 2, 4, 4, 4 and 4, and that of 57 kD protein were 2, 5, 2, 5 and 2. There were difference between the disorders, globulins, phosphorylation sites and B cell antigen epitopes of 129 kD and 57 kD proteins of tested CGMMV isolates. The current results that there was no significant difference between the replicase gene sequences, it was stable and conservative for intra-species and clearly difference for inter-species. CGMMV-No. 1, CGMMV-No. 3, CGMMV-No. 4 and CGMMV-No. 5 had. a close genetic relationship with Shandong and Liangning isolates (Accession No. KJ754195 and EF611826), they are potentially originate from the same source. CGMMV-No. 2 was closer with Korea isolate. High sequence similarity of tested samples were gathered for a class in phylogenetic tree. It didn't show regularity of the bioinformatics analysis results of 129 kD and 57 kD proteins of tested CGMMV isolates. There was no corresponding relationship among the molecular phylogeny and the bioinformatics analysis of the tested CGMMV isolates.
Computational Biology ; Cucumis sativus ; chemistry ; classification ; enzymology ; genetics ; Molecular Sequence Data ; Phylogeny ; Plant Diseases ; virology ; RNA Replicase ; chemistry ; genetics ; metabolism ; Sequence Homology, Nucleic Acid ; Viral Proteins ; chemistry ; genetics ; metabolism