Project description:The abscisic acid (ABA) increase and auxin decline are both indicators of ripening initiation in grape berry, and norisoprenoid accumulation also start at around the onset of ripening. To investigate the transcriptional and posttranscriptional regulation of the ABA and synthetic auxin 1-naphthaleneacetic acid (NAA) on norisoprenoid production, we performed time series GC-MS and RNA-seq analyses on Cabernet Sauvignon grape berries from pre-veraison to ripening. Higher levels of free norisoprenoids were found in ABA-treated mature berries in two consecutive seasons, and both free and total norisoprenoids were significantly increased by NAA in one season. The expression pattern of known norisoprenoid-associated genes in all samples and the up-regulation of specific alternative splicing isoforms of VviDXS and VviCRTISO in NAA-treated berries were predicted to contribute to it. Combined weighted gene co-expression network analysis (WGCNA) and promoter motif prediction analysis suggested that GATA26 and GATA28 could be potential regulators of norisoprenoid accumulation. Finally, the network analysis uncovered the interaction between previously identified switch genes, hormone-related genes and norisoprenoid-associated genes.
Project description:SuperSAGE is a method of digital gene expression profiling that allows isolation of 26bp tag fragments from expressed transcripts. Because its tag size is larger than that of conventional SAGE, SuperSAGE allowed a secure tag-to-gene annotation using BLAST search against grape genome databases.Transcript profiles in nine samples of grape berry tissues under different light conditions were obtained by SuperSAGE analysis and used for screening the genes which have co-ordinated transcript profiles with the change in the flavonoid composition in the samples analyzed. Candidate genes related to flavonoid biosynthesis and regulation were identified. Nine different grape samples, i.e., flowers, grape berries of Cabernet Sauvignon at 2, 7, 9 weeks after flowering (WAF), berry skins at 17 days after flowering (DAF) shaded after flowering, and berry skins at 17DAF shaded from flowering to 14DAF and then light exposed, were analyzed.
Project description:Dissecting the biochemical and transcriptomic effects of locally applied heat stress on developing Cabernet Sauvignon grape berries
Project description:To obtain an interpretation from the view of transcriptome on distinct metabolite accumulation between ecologically different regions in China, next-generation sequencing technology was performed on E-L 31, 35 and 38 stages of Cabernet Sauvignon grape berries from Changli (CL, eastern) and Gaotai (GT, western). The transcript abundance of epoxycarotenoid dioxygenase and xanthoxin dehydrogenase required for ABA biosynthesis was significantly higher in the GT berries at E-L 35 and 38 stages compared with the CL berries, which may explain the relatively short maturation period of berries in the western region. Some genes required for carbohydrate metabolism, such as hexose transporter, L-idonate dehydrogenase and phosphoenolpyruvate carboxylase, were significantly up-regulated in the CL berries in relative to the GT berries, which positively correlated with the sugar and organic acid accumulations. Pathway enrichment analysis of differentially expressed genes revealed that the CL berries had higher levels of phenylpropanoid biosynthesis at E-L 38 stage than the GT berries, which may relate to the quick fading of the GT wines because of weak co-pigmentation. cDNA libraries generated from three developmental stages (E-L 31, 35 and 38) of Cabernet Sauvignon grape berries from Changli (CL, eastern) and Gaotai (GT, western) in China were sequenced using Illumina HiSeq 2000.
Project description:Light environments have long been known to influence grape (Vitis vinifera L.) berry development and biosynthesis of phenolic compounds, and ultimately affect wine quality. Here, the accumulation and compositional changes of hydroxycinnamic acids (HCAs) and flavonoids, as well as global gene expression were analyzed in Cabernet Sauvignon grape berries under sunlight exposure treatments at different phenological stages. Sunlight exposure did not consistently affect the accumulation of berry skin flavan-3-ol or anthocyanin among different seasons due to climatic variations, but increased HCA content significantly at véraison and harvest, and enhanced flavonol accumulation dramatically with its timing and severity degree trend. As in sunlight exposed berries, a highly significant correlation was observed between the expression of genes coding phenylalanine ammonia-lyase, 4-coumarate: CoA ligase, flavanone 3-hydroxylase and flavonol synthase family members and corresponding metabolite accumulation in the phenolic biosynthesis pathway, which may positively or negatively be regulated by MYB, bHLH, WRKY, AP2/EREBP, C2C2, NAC, and C2H2 transcription factors (TFs). Furthermore, some candidate genes required for auxin, ethylene and abscisic acid signal transductions were also identified which are probably involved in berry development and flavonoid biosynthesis in response to enhanced sunlight irradiation. Taken together, this study provides a valuable overview of the light-induced phenolic metabolism and transcriptome changes, especially the dynamic responses of TFs and signaling components of phytohormones, and contributes to the further understanding of sunlight-responsive phenolic biosynthesis regulation in grape berries.
Project description:Transcriptional changes occurring in grape berries (Vitis vinefera L. cv Cabernet Sauvignon) cultured in vitro with high (468 mM) and low (58 mM) concentrations of glucose in the culture medium was verified. Gene expression profiling was done using the Nimblegen whole genome array with 3 biological replicates.
Project description:We used Affymetrix microarray analyses of thirty-two individual Vitis vinifera cv. Cabernet Sauvignon berries sampled from two clusters at fifty-percent ripening initiation. By delineating four developmental stages of ripening initiation, we demonstrate that color is a statistically significant indicator of transcriptional state during ripening initiation. We report on clustered gene expression patterns which were mined for genes annotated with signal transduction functions in order to advance regulatory network modeling of ripening initiation in grape berries. We also demonstrated that gene expression does not differ statistically significantly at a global level in berries sampled from different plants or different positions in a cluster. Keywords: time course (berry development series)