Project description:Grape berries undergo considerable physical and biochemical changes during the ripening process. Ripening is characterized by a number of changes, including the degradation of chlorophyll, an increase in berry deformability, a rapid increase in the level of hexoses in the berry vacuole, an increase in berry volume, the catabolism of organic acids, the development of skin colour, and the formation of compounds that influence flavour, aroma, and therefore, wine quality. The aim of this work is to identify differentially expressed genes during grape ripening by microarray and real-time PCR techniques. Using a custom array of new generation, we analysed the expression of 6000 grape genes from pre-veraison to full maturity, in Vitis vinifera cultivar Muscat of Hamburg, in two different years (2006 and 2007). Five time points per year and two biological replicates per stadium were considered. To reduced intra-plant and inter-plant biological variability, for each ripening stadium we collected around hundred berries from several bunch grapes of five plants of V. vinifera cv Muscat of Hamburg. We will use the real-time PCR technique to validate microarray data.Muscat of Hamburg. We will use the real-time PCR technique to validate microarray data.
Project description:Two small RNA libraries were generated from micropropagated ‘Muscat Hamburg’ (Vitis vinifera) plantlets under normal and low temperatures (4 °C). A total of 163 known miRNAs and 299 putative novel miRNAs were detected from two small RNA libraries by Solexa sequencing. Forty-four cold-inducible miRNAs were identified through differentially expressed miRNAs (DEMs) analysis; among which, 13 belonged to upregulated DEMs while 31 belonged downregulated DEMs. This study indicated that a diverse set of miRNAs in V. vinifera are cold-inducible and may play an important role in cold stress response.
Project description:We determined the RNA sequence of V. vinifera cv. Victoria and V. vinifera cv. Muscat Hamburg grapes to reveal the transcriptomics variations between summer and winter berries under a double cropping system. Transcriptomics analysis showed that the upregulated VviDXSs, VviPSYs, and VviCCDs expressions might contribute to accumulations of terpenes or norisoprenoids in winter berries.
Project description:Grape volatiles include a great number of compounds, among which monoterpenes, alcohols,esters and carbonyls were found.Grape may be divided into aromatic and non-aromatic varieties. ‘Shine Muscat’ belongs to the aromatic cultivar. The most abundant free compounds detected in Muscat grape were linalool, geraniol, citronellol, nerol. Grapevine (Vitis vinifera L.) is an economically important and widely cultivated fruit crop. Grape quality is important for its market value and is largely decided by its taste and aroma.Gas-chromatograph mass-spectrometry (GC-MS) was performed to observe changes of the volatile compounds.
Project description:Two small RNA libraries were generated from micropropagated â??Muscat Hamburgâ?? (Vitis vinifera) plantlets under normal and low temperatures (4 °C). A total of 163 known miRNAs and 299 putative novel miRNAs were detected from two small RNA libraries by Solexa sequencing. Forty-four cold-inducible miRNAs were identified through differentially expressed miRNAs (DEMs) analysis; among which, 13 belonged to upregulated DEMs while 31 belonged downregulated DEMs. This study indicated that a diverse set of miRNAs in V. vinifera are cold-inducible and may play an important role in cold stress response. Examination of small RNA populations in grapevine under cold treatment and none cold treatment.
Project description:Monoterpenes are typical aroma components of muscat grape cultivars. However, the molecular mechanism of monoterpene biosynthesis between muscat and non-muscat grape remains unclear. In this study, two F1 hybrids with different aroma profiles from the cross between 'Midknight Beauty' and 'Red Globe' grapes were chosen for comprehensive transcriptome and metabolome analysis to study the unique monoterpenoid accumulation pattern and related candidate genes. The results showed that in the hybrid progeny, the concentrations of most terpenoids differed at different times, and the concentration of most terpenoids increased from the pre-veraison to veraison, followed by a decreasing trend from veraison to maturity. In the F1 generation, the concentration of monoterpenes accumulated in Muscat grapes was significantly higher than that in Neutral grapes. Furthermore, linalool,α-terpineol, and L-α-terpineol may be important odorants that affect the floral characteristics of Muscat grapes because of their high odor activity values (OAVs). Transcriptional analysis identified 3 VvDXS (LOC100249323, LOC100268079, LOC100247834), 1 VvHDS (LOC100257071), 1 VvMVK (LOC100251148), 1 VvHMGR (LOC100265082), and 1 VvGGPPS (LOC100257234) in the MEP and MVA pathways. Meanwhile, 11 TPS genes that may be involved in the regulation of monoterpenes were identified. Among them, VvTPS (LOC100853562) showed consistency with the accumulation of monoterpenes and had a high expression level, MYB (LOC100255488), GATA (LOC100262474), and ERF (LOC100255943, LOC100260401) were selected as candidate transcription factors (TFs). The findings provide new insights for the subsequent functional validation and further investigation of genes related to monoterpene synthesis in Muscat aroma grapes.