Glucosidases are an indispensable class of enzymes in the sugar metabolism of organisms. To investigate the biological functions and expression patterns of α-glucosidases (AGLUs) and β-glucosidases (BGLUs), we identified the two family members in the genome of melon (Cucumis melo). The number, location on chromosomes, gene structure, subcellular localization, conserved motifs, and phylogenetic relationship of the two family members were analyzed. Based on the cis-acting elements in the promoter region and protein interaction models, their functions were preliminarily predicted. Furthermore, the gene expression of the two family members was determined by qRT-PCR. The results showed that the melon genome contained five AGLU family members on five chromosomes, and all of the five members were located in the extracellular matrix, with the amino acid sequence lengths ranging from 899 aa to 1 060 aa. The melon genome carried 18 BGLU family members on 8 chromosomes, and all the members were located in the cell membrane or cytoplasm, with the amino acid lengths ranging from 151 aa to 576 aa. The qRT-PCR results showed that the expression of about 50% of the genes was down-regulated upon cold stress. CmAGLU5 and CmBGLU7 may be key members of the two families, respectively, in response to cold stress. The expression of all members of the two families was up-regulated under abscisic acid (ABA), high salt, and drought stress. In the AGLU family, CmAGLU3 was the key gene in response to ABA and high salt stress, while CmAGLU4 was the key gene in response to drought stress. In the BGLU family, CmBGLU18 was the key gene in response to ABA, while CmBGLU6 was the key gene in response to high salt and drought stress.
beta-Glucosidase/metabolism* ; Phylogeny ; alpha-Glucosidases/metabolism* ; Gene Expression Regulation, Plant ; Cucurbitaceae/enzymology* ; Multigene Family ; Cucumis melo/enzymology* ; Stress, Physiological

Cucumber (Cucumis sativus L.) is one of the most widely cultivated vegetables in the world. High temperature and other stress conditions can affect the growth and development of this plant, even leading to the decreases in yield and quality. The mitogen-activated protein kinase (MAPK) family plays a crucial role in plant stress responses. However, the role of MPK4 in the stress response of cucumber remains to be reported. In this study, we cloned CsMPK4, which encoded 383 amino acid residues. The qRT-PCR results showed that the expression level of CsMPK4 was the highest in leaves and flowers, moderate in roots, and the lowest in stems and tendrils. CsMPK4 was located in the nucleus and cytoplasm, and it had a close relationship with CmMPK4 in muskmelon. The cucumber plants overexpressing CsMPK4 became stronger and shorter, with reduced length and quantity of tendrils. Moreover, the transgenic seedlings were more resistant to high temperatures, with decreased malondialdehyde (MDA) content and increased activities of peroxidase (POD) and superoxide dismutase (SOD) in young leaves. Furthermore, the protein-protein interaction between CsMPK4 and CsVQ10, a member of the valine-glutamine family, was confirmed by yeast two-hybrid and bimolecular fluorescence complementation (BiFC) assays. The results suggested that CsVQ10 cooperated with CsMPK4 in response to the high temperature stress in cucumber. This study laid a foundation for the further study on the stress response mechanism of CsMPK4 and the breeding of stress-resistant cucumber varieties.
Cucumis sativus/metabolism* ; Mitogen-Activated Protein Kinases/physiology* ; Plant Proteins/metabolism* ; Plants, Genetically Modified/metabolism* ; Gene Expression Regulation, Plant ; Stress, Physiological/genetics* ; Cloning, Molecular

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

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

BACKGROUND: Recently, the prevalence of food allergies during childhood is increasing, with fruits being common allergens. However, data on allergens that cause fruit and vegetable allergies and pollen-food allergy syndrome (PFAS) in childhood are relatively few. This study aimed to examine the allergens in fruit and vegetable allergies in pediatric patients and to determine the association between fruit and vegetable allergies and PFAS.OBJECTIVE: This study aimed to examine the current status of fruit and vegetable allergies in Japanese children.METHODS: This was a multicenter case series observational study. The participants included children aged <15 years who developed allergic symptoms after eating fruits and vegetables and subsequently received treatment in the Pediatric Department of 6 hospitals in the Osaka Prefecture in Japan during the study period from August 2016 to July 2017. Participants' information was obtained using a questionnaire, and data were obtained by performing several types of allergy tests using blood samples.RESULTS: A total of 97 children (median age, 9 years; 56 males) were included in the study. Apple was the most common allergen, followed by peach, kiwi, cantaloupe, and watermelon. A total of 74 participants (76%) exhibited allergic symptoms due to PFAS; moreover, pathogenesis-related protein-10 (PR-10) was the most common allergen superfamily. On the contrary, in the group where neither PR-10 nor profilin was sensitized, kiwi and banana were the most common allergens, and the age of onset was lower than that in the PFAS group. Specific antibody titer was significantly associated with Birch for Bet v1 and latex for Bet v2 (r = 0.99 and r = 0.89).CONCLUSION: When we examine patients with fruit and vegetable allergies, we should first consider PFAS even in childhood specifically for children greater than 4 years old.
Age of Onset ; Allergens ; Asian Continental Ancestry Group ; Betula ; Child ; Citrullus ; Clinical Study ; Cucumis melo ; Eating ; Food Hypersensitivity ; Fruit ; Humans ; Hypersensitivity ; Japan ; Latex ; Musa ; Observational Study ; Prevalence ; Profilins ; Prunus persica ; Rhinitis ; Rhinitis, Allergic, Seasonal ; Vegetables

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

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.

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

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

Gummy stem blight, a plant disease caused by Didymella bryoniae, is one of the major diseases in melon. The disease can seriously reduce melon yield and quality. However, little information is available on the genetics and functional genomics of the fungal pathogen. In this study, we developed an Agrobacterium-mediated transformation system for D. bryoniae by using a universal pathogenic isolate DB11 and the Agrobacterium tumefaciens strain C58C1 carrying plasmid pBIG2RHPH2 harboring the hygromycin B phosphotransferase gene (hph). Total 45 transformants could be obtained per 1 x 10(5) spores when 1 x 10(6) spores per milliliter of D. bryoniae spore suspension were cocultivated with Agrobacterium cells at OD600 = 0.15 for 48 h in the presence of induction medium (pH 5.2) containing acetosyringone at 200 microg/mL and selection medium contained 100 microg/mL of hygromycin B and 200 microg/mL of cefotaxime sodium, ampicillin and tetracycline, respectively. The transformants were stable when grown on PDA medium without hygromycin B for five times and were verified by PCR amplification with the hph primers and by Southern blot analysis with the hph probe. The transformation system will be useful for further studies of functional genes in D. bryoniae.
Agrobacterium tumefaciens ; genetics ; Ascomycota ; genetics ; Cucumis melo ; microbiology ; Plant Diseases ; microbiology ; Plants, Genetically Modified ; Transformation, Genetic