Project description:Melon (Cucumis melo L.) is a commercially important fruit crop that is cultivated worldwide. The melon research community has recently benefited from the determination of a complete draft genome sequence and the development of associated genomic tools, which have allowed us to focus on small RNAs (sRNAs). These are short, non-coding RNAs 21â24 nucleotides in length with diverse physiological roles. In plants, they regulate gene expression and heterochromatin assembly, and control protection against virus infection. Much remains to be learned about the role of sRNAs in melon. We constructed 10 sRNA libraries from two stages of developing ovaries, fruits and photosynthetic cotyledons infected with viruses, and carried out high-throughput pyrosequencing. We catalogued and analyzed the melon sRNAs, resulting in the identification of 26 known miRNA families (many conserved with other species), the prediction of 84 melon-specific miRNA candidates, the identification of trans-acting siRNAs, and the identification of chloroplast, mitochondrion and transposon-derived sRNAs. In silico analysis revealed more than 400 potential targets for the conserved and novel miRNAs. This analysis provides insight into the composition and function of the melon small RNAome, and paves the way towards an understanding of sRNA-mediated processes that regulate melon fruit development and melonâvirus interactions. 11 small RNA libraries from several tissues of melon are included en the raw data. 2 samples from ovary, 2 samples from fruit, 1 sample from healthy cotyledons (Cultivar Tendral), 1 samples from healthy cotyledons (genotype TGR-1551), 1 sample from cotyledons (cultivar Tendral) infected with Watermelon mosaic virus (WMV), 1 sample from cotyledons (cultivar TGR-1551) infected with WMV, 1 sample from cotyledons (cultivar Tendral) infected with Melon necrotic spot virus (MNSV, Malfa5 isolate), 1 sample from cotyledons (cultivar Tendral) infected with MNSV (chimeric virus with Malfa5-264 isolates), 1 library from synthetic RNA oligos. Raw reads were obtained from two independent 454 runs, ~22,000 reads each one, to a total of 447,180 reads
Project description:Melon (Cucumis melo L.) is a commercially important fruit crop that is cultivated worldwide. The melon research community has recently benefited from the determination of a complete draft genome sequence and the development of associated genomic tools, which have allowed us to focus on small RNAs (sRNAs). These are short, non-coding RNAs 21â24 nucleotides in length with diverse physiological roles. In plants, they regulate gene expression and heterochromatin assembly, and control protection against virus infection. Much remains to be learned about the role of sRNAs in melon. We constructed 10 sRNA libraries from two stages of developing ovaries, fruits and photosynthetic cotyledons infected with viruses, and carried out high-throughput pyrosequencing. We catalogued and analyzed the melon sRNAs, resulting in the identification of 26 known miRNA families (many conserved with other species), the prediction of 84 melon-specific miRNA candidates, the identification of trans-acting siRNAs, and the identification of chloroplast, mitochondrion and transposon-derived sRNAs. In silico analysis revealed more than 400 potential targets for the conserved and novel miRNAs. This analysis provides insight into the composition and function of the melon small RNAome, and paves the way towards an understanding of sRNA-mediated processes that regulate melon fruit development and melonâvirus interactions.
Project description:One of the methods used to search for molecular markers is DNA hybridization to microarrays. Microarray hybridization of DNA from different individuals can reveal differences between them (single-feature polymorphisms (SFPs)). These SFPs can be used as markers for breeding purposes, or they can be converted to conventional markers by sequencing. This method has been utilized in a few different plants to discover genetic variation using Affymetrix arrays that exist for only a few organisms. We applied this approach, with some modifications, for marker discovery in melon. For marker discovery, we used DNA from the parents of our mapping population, developed by Katzir's group from a cross between representatives of two subspecies of Cucumis melo L.: PI414723 (subspecies agrestis) and 'Dulce' (subspecies melo). Two biological replicates from PI414723 and two from 'Dulce' were used. Each biological replicate contained gDNAs pooled from 10 different plants. gDNA samples were labeled and hybridized using standard Agilent procedures for comparative genomic hybridization (CGH). The inter-population genetic variation was detected using two arrays, with one of the biological replicates of 'Dulce' against one of the PI414723 replicates on each array. The intra-population variation was detected by hybridizing the PI414723 replicates against each other and the 'Dulce' replicates against each other. Intra-population variation was estimated to ensure that the genetic variation between these populations is based on alleles that are fixed in the population and not due to intra-population variation.
Project description:<p>Grafting is widely applied in the cultivation of melon. In this study, 'Qinmi No.1' [<em>Cucumis melo </em>L.<em> </em>(QG)] and 'Ribenxuesong' [<em>Cucurbita maxima</em> Duch. (RG)] were used as rootstocks for 'QingxinYangjiaocui' (<em>Cucumis melo</em> L.). The results showed that grafting with muskmelon rootstocks had no significant effect on fruit aroma, but grafting with pumpkin rootstocks significantly reduced the odor intensity and odor preference scores of melon fruits. Compared with the fruits from self-grafted plants (SG), four new aromatic volatiles with a sweet smell were detected, the alcohol dehydrogenase (ADH) activity was significantly decreased at 30 DAP, but unaffected at 42 DAP in QG fruits. There was no difference for alcohol acetyltransferase (AAT) activity between QG and SG fruits. The expression level of CmADH2 was significantly higher at 30 DAP and 42 DAP, but CmAAT2 was significantly lower at 42 DAP in QG fruits compared with SG fruits. In RG fruits, the main aroma compounds including butanoic acid ethyl ester, 2-methyl-2-butenal and 2-methylheptan-1-al were absent, while the volatile compounds with unpleasant odor characteristics including trans, cis-2,6-nonadien-1-ol, (E,E)-2,4-heptadienal, octanoic acid and styrene were detected. Compared with SG fruits, 1-nonanol and 1-heptanol with green odor characteristics were significantly increased, but eucalyptol and farnesene with fruity aroma characteristics were significantly decreased in RG fruits. The ADH activity of RG fruits was significantly lower than that of SG fruits at 30 DAP and the AAT activity was significantly lower than that of SG fruits at 42 DAP. In addition, the expression levels of CmADH and CmAAT homologs in RG fruits were significantly lower than those in SG or QG fruits. These results show that grafting with pumpkin rootstocks affected the main aroma components, reduced ADH and AAT activities, and down-regulated the expression levels of CmADHs and CmAATs in the melon fruits. This study reveals the mechanism of different rootstocks on melon fruit aroma quality, and lays a theoretical foundation for the selection of rootstocks in melon production. Future studies using overexpression or CRISPR/CAS system to obtain stable transgenic lines of genes encoding key aromatic volatiles, would be promising to effectively improve the flavor quality of melon.</p>
Project description:We report the application of a high-throughput technique, RNA-seq, to study the transcriptomic response of cucumis melo seeds and leaves to the treatment with B. subtilis cells or the secondary metabolite fengycin
Project description:We used a melon oligo-based microarray to investigate the gene expression responses of two melon genotypes with contrasting resistance to Monosporascus cannonballus at 1 and 3 days after infection
Project description:<p>Melon (<em>Cucumis melo</em> L.) is an agronomically important vegetable. Most cultivars of melon are andromonoecious and bisexual flowers only emerged from the leaf axil of lateral branches. However, the regulatory mechanism contributing to the occurrence of bisexual flowers were still obscure. In this study, ethephon was applied in two common cultivars of melon. In control without ethephon treatment, no bisexual flower was made in the main stem. However, 6.56 ± 1.42 and 6.63 ± 0.55 bisexual flowers were respectively induced in main stem of ‘Yangjiaocui-QX’ and ‘Lvbao’ after ethephon treatment, and induced bisexual flowers distributed in 12–20 nodes of main stem. During the formation of bisexual flowers, 41 metabolites were significantly up-regulated and 98 metabolites were significantly down-regulated. According to the KEGG enrichment analysis of 139 different metabolites, a total of 30 pathways were mapped and KEGG terms of “Phenylalanine, tyrosine and tryptophan biosynthesis”, “Phenylalanine metabolism” and “Flavone and flavonol biosynthesis” were significantly enriched. In three significantly enriched KEGG terms, shikimic acid, L-tryptophan, L-phenylalanine and kaempferol were significantly up-regulated while L-tyrosine, 4-hydroxycinnami acid and luteolin were significantly down-regulated in ET compared to CK. Different metabolites were also classified depend on major class features and 14 classes were acquired. The results of metabonomics and endogenous hormone identification indicated that ethylene could enhance the concentration of salicylic acid, methyl jasmonate, ABA and IAA. This study provided an important theoretical foundation for inducing bisexual flowers in main stem and breeding new varieties of melon in future.</p>
Project description:Purpose: the goals of this study are to compare fruit of two clitivars oriental melon transcriptome profiling (RNA-seq) at different stages to explore carotenoid potentail carotenoid accumulation mechanism Methods:The transcriptome sequence of two cultivars oriental melon fruits at different stages were generated by deep sequencing with three repeats using Illumina. The sequence reads that passed filters were mapped to melon genome (http://cucurbitgenomics.org/organism/18) using HISAT2 software. The differently expressed genes were identify by |log2(FoldChange)| > 0 & padj <= 0.05, and qRT–PCR validation was performed using SYBR Green assays Result:Using an optimized data analysis workflow, we mapped about 40 million sequence reads per sample to the melon genome. The differentially expressed genes were functionally classified by GO and KEGG enrichment. We focused on carotenoid metabolism related gene and validated using qRT-PCR. The results showed RNA-seq and qRT-PCR were highly correlated. Conclusion: Our study provided transcriptome sequence of oriental melon fruits at different stages in two cultivars. The optimized data analysis workflows reported here should provide comparative framework of expression profiles. Our transcriptome characterization contribute to analyze gene functions and metabolic process of oriental melon.
2022-01-13 | GSE193412 | GEO
Project description:Whole genome sequencing of melon (Cucumis melo L.)