Project description:Grapevine cluster compactness is a multi-componential trait of agronomical interest; it greatly influences the vineyard management and the visual aspect of table grape. Clusters with greater compactness are more susceptible to disease. The compactness can be break down in a patchwork of agronomical traits, each having agronomical importance that includes parameters related to inflorescence and cluster architecture (cluster length and width, length of pedicels, etc.), fruitfulness (number of berries, number of seeds) and berry (size, shape, volume...). Through visual evaluation of a collection of 730 clones from the cultivar Tempranillo and 501 clones from Garnacha Tinta we identified and fully phenotyped distinct clones which transcriptomes were compared at key developmental stages in order to identify the genes playing a role in mechanisms involved in cluster compactness such as the ones determining number of berries, cluster length or berry size. Key genes involved in this process were identified. The findings lead us to hypothesize that berry size and/or number at ripening are greatly influenced by the rate of cell replication in flowers during the first stages after pollination.
Project description:Background: Grapevine berry, a nonclimacteric fruit, goes through three developmental stages, the last one called the ripening stage, when the berry changes color and dramatically increases in sugar. Flavors derived from terpenoid and fatty acid metabolism develop at the very end of this ripening stage. Whole-genome microarray analysis was used to assess the transcriptomic response of pulp and skin of Cabernet Sauvignon berries in the latter stages of ripening between 22 and 37 M-BM-0Brix. Grapevine berry, a nonclimacteric fruit, goes through three developmental stages, the last one called the ripening stage, when the berry changes color and dramatically increases in sugar. Flavors derived from terpenoid and fatty acid metabolism develop at the very end of this ripening stage. Whole-genome microarray analysis was used to assess the transcriptomic response of pulp and skin of Cabernet Sauvignon berries in the latter stages of ripening between 22 and 37 M-BM-0Brix. Results: There were approximatedly 18,000 transcripts whose abundance changed with M-BM-0Brix level and tissue type. There were very broad changes in many gene ontology (GO) categories involving metabolism, signaling and abiotic stress. GO categories reflecting tissue differences were overrepresentation in photoysynthesis, isoprenoid metabolism and pigment biosynthesis. A more detailed analysis of the interaction of the skin and pulp with M-BM-0Brix levels revealed that there were significantly higher abundances of transcripts changing with M-BM-0Brix level in the skin that were involved in ethylene signaling, isoprenoid and fatty acid metabolism. Many of these transcripts were peaking around the optimal fruit stage for flavor production. The transcript abundance of approximately two-thirds of the AP2/ERF Superfamily of transcription factors changed during these developmental stages. The transcript abundance of a unique clade of ERF6-type transcription factors had the largest changes and clustered with other genes involved in ethylene, senescence, and fruit flavor production including ACC oxidase, terpene synthases, and lipoxygenases. The transcript abundance of other important transcription factors (i.e. SPL, RIN, etc.) involved in the regulation of fruit ripening was also higher in the skin. Conclusions: A detailed analysis of the transcriptomic response of grapevine berries revealed that these berries went through massive changes in chemical signaling and metabolism in both the pulp and skin, particularly in the skin. The ethylene signaling pathway of this nonclimacteric fruit was significantly stimulated in the late stages of ripening when the production of transcripts for important flavor and aroma compounds were at their highest. Ethylene transcription factors known to play a role in leaf senescence also appear to play a role in fruit senescence. Ethylene may play a bigger role than previously thought in this non-climacteric fruit. Vitis vinifera L. cv. Cabernet Sauvignon (clone 8 scion on 1130 Paulsen rootstock) berries were harvested from J. Lohr Vineyards & Wines, Paso Robles, CA, USA. Whole-genome microarray analysis was used to assess the transcriptomic response of pulp and skin of berries in the latter stages of ripening between 22 and 37 M-BM-0Brix (2008 vintage).
Project description:MicroRNAs (miRNAs) play a important part in post-transcriptional gene regulation and have been shown to control many genes involved in various biological and metabolic processes. There have been extensive studies to discover miRNAs and analyze their functions in model plant species, such as Arabidopsis and rice and other plants. However, the number of miRNAs discovered in grape is relatively low and little is known about miRNAs responded gibberellin during fruit germination. In this study, a small RNA library from gibberellin grape fruits was sequenced by the high throughput sequencing technology. A total of 16,033,273 reads were obtained. 812,099 total reads representing 1726 unique sRNAs matched to known grape miRNAs. Further analysis confirmed a total of 149 conserved grapevine miRNA (Vv-miRNA) belonging to 27 Vv-miRNA families were validated, and 74 novel potential grapevine-specific miRNAs and 23 corresponding novel miRNAs* were discovered. Twenty-seven (36.5%) of the novel miRNAs exhibited differential QRT-PCR expression profiles in different development gibberellin-treated grapevine berries that could further confirm their existence in grapevine. QRT-PCR analysis on transcript abundance of 27 conserved miRNA family and the new candidate miRNAs revealed that most of them were differentially regulated by the gibberellin, with most conserved miRNA family and 26 miRNAs being specifically induced by gibberellin exposure. All novel sequences had not been earlier described in other plant species. In addition, 117 target genes for 29 novel miRNAs were successfully predicted. Our results indicated that miRNA-mediated gene expression regulation is present in gibberellin-treated grape berries. This study led to the confirmation of 101 known miRNAs and the discovery of 74 novel miRNAs in grapevine. Identification of miRNAs resulted in significant enrichment of the gibberellin of grapevine miRNAs and provided insights into miRNA regulation of genes expressed in grape berries. GSM604831 is the control for the gibberellin-treated sample.
Project description:Grapevine cluster compactness is a multi-componential trait of agronomical interest; it greatly influences the vineyard management and the visual aspect of table grape. Clusters with greater compactness are more susceptible to disease. The compactness can be break down in a patchwork of agronomical traits, each having agronomical importance that includes parameters related to inflorescence and cluster architecture (cluster length and width, length of pedicels, etc.), fruitfulness (number of berries, number of seeds) and berry (size, shape, volume...). Through visual evaluation of a collection of 730 clones from the cultivar Tempranillo and 501 clones from Garnacha Tinta we identified and fully phenotyped distinct clones which transcriptomes were compared at key developmental stages in order to identify the genes playing a role in mechanisms involved in cluster compactness such as the ones determining number of berries, cluster length or berry size. Key genes involved in this process were identified. The findings lead us to hypothesize that berry size and/or number at ripening are greatly influenced by the rate of cell replication in flowers during the first stages after pollination. A total of 57 samples were hybridized. Comparison G1 was performed between clones showing differences in the cluster compactness and in the total number of berries per cluster and berries size (compact: clone 1134. loose: clone 0368). Comparison G2 was performed between two compact clones (Garnacha Tinta 147 and 1134) significantly differing for cluster length and number of nodes (branches) of the rachis. Comparison G3 was performed with two loose clones (Garnacha Tinta 681 and 1154) differing in the number of nodes of the rachis (p<0.01). Comparisons G4 and T were performed between clones showing differences in the cluster compactness and in the total number of berries per cluster (compact: clones 0906 and 0126. loose: clones 1154 and 1041).
Project description:Background: Grapevine berry, a nonclimacteric fruit, goes through three developmental stages, the last one called the ripening stage, when the berry changes color and dramatically increases in sugar. Flavors derived from terpenoid and fatty acid metabolism develop at the very end of this ripening stage. Whole-genome microarray analysis was used to assess the transcriptomic response of pulp and skin of Cabernet Sauvignon berries in the latter stages of ripening between 22 and 37 °Brix. Grapevine berry, a nonclimacteric fruit, goes through three developmental stages, the last one called the ripening stage, when the berry changes color and dramatically increases in sugar. Flavors derived from terpenoid and fatty acid metabolism develop at the very end of this ripening stage. Whole-genome microarray analysis was used to assess the transcriptomic response of pulp and skin of Cabernet Sauvignon berries in the latter stages of ripening between 22 and 37 °Brix. Results: There were approximatedly 18,000 transcripts whose abundance changed with °Brix level and tissue type. There were very broad changes in many gene ontology (GO) categories involving metabolism, signaling and abiotic stress. GO categories reflecting tissue differences were overrepresentation in photoysynthesis, isoprenoid metabolism and pigment biosynthesis. A more detailed analysis of the interaction of the skin and pulp with °Brix levels revealed that there were significantly higher abundances of transcripts changing with °Brix level in the skin that were involved in ethylene signaling, isoprenoid and fatty acid metabolism. Many of these transcripts were peaking around the optimal fruit stage for flavor production. The transcript abundance of approximately two-thirds of the AP2/ERF Superfamily of transcription factors changed during these developmental stages. The transcript abundance of a unique clade of ERF6-type transcription factors had the largest changes and clustered with other genes involved in ethylene, senescence, and fruit flavor production including ACC oxidase, terpene synthases, and lipoxygenases. The transcript abundance of other important transcription factors (i.e. SPL, RIN, etc.) involved in the regulation of fruit ripening was also higher in the skin. Conclusions: A detailed analysis of the transcriptomic response of grapevine berries revealed that these berries went through massive changes in chemical signaling and metabolism in both the pulp and skin, particularly in the skin. The ethylene signaling pathway of this nonclimacteric fruit was significantly stimulated in the late stages of ripening when the production of transcripts for important flavor and aroma compounds were at their highest. Ethylene transcription factors known to play a role in leaf senescence also appear to play a role in fruit senescence. Ethylene may play a bigger role than previously thought in this non-climacteric fruit.
Project description:MicroRNAs (miRNAs) play a important part in post-transcriptional gene regulation and have been shown to control many genes involved in various biological and metabolic processes. There have been extensive studies to discover miRNAs and analyze their functions in model plant species, such as Arabidopsis and rice and other plants. However, the number of miRNAs discovered in grape is relatively low and little is known about miRNAs responded gibberellin during fruit germination. In this study, a small RNA library from gibberellin grape fruits was sequenced by the high throughput sequencing technology. A total of 16,033,273 reads were obtained. 812,099 total reads representing 1726 unique sRNAs matched to known grape miRNAs. Further analysis confirmed a total of 149 conserved grapevine miRNA (Vv-miRNA) belonging to 27 Vv-miRNA families were validated, and 74 novel potential grapevine-specific miRNAs and 23 corresponding novel miRNAs* were discovered. Twenty-seven (36.5%) of the novel miRNAs exhibited differential QRT-PCR expression profiles in different development gibberellin-treated grapevine berries that could further confirm their existence in grapevine. QRT-PCR analysis on transcript abundance of 27 conserved miRNA family and the new candidate miRNAs revealed that most of them were differentially regulated by the gibberellin, with most conserved miRNA family and 26 miRNAs being specifically induced by gibberellin exposure. All novel sequences had not been earlier described in other plant species. In addition, 117 target genes for 29 novel miRNAs were successfully predicted. Our results indicated that miRNA-mediated gene expression regulation is present in gibberellin-treated grape berries. This study led to the confirmation of 101 known miRNAs and the discovery of 74 novel miRNAs in grapevine. Identification of miRNAs resulted in significant enrichment of the gibberellin of grapevine miRNAs and provided insights into miRNA regulation of genes expressed in grape berries. GSM604831 is the control for the gibberellin-treated sample. The mixture samples of young berries (one week after flowering) large berries (five week after flowering after flowering), and old berries (nine week after flowering) treated with gibberellin, respectively, were generated by deep sequencing, in triplicate, using Illumina 1G Genome Analyzer.
Project description:Background: Cluster thinning is an agronomic practice in which a proportion of berry clusters are removed from the vine to increase the source/sink ratio and improve the quality of the remaining berries. Until now no transcriptomic data have been reported describing the mechanisms that underlie the agronomic and biochemical effects of thinning. Results: We profiled the transcriptome of Vitis vinifera cv. Sangiovese berries before and after thinning at veraison using a genome-wide microarray representing all grapevine genes listed in the latest V1 gene prediction. Thinning increased the source/sink ratio from 0.6 to 1.2 m2 leaf area per kg of berries and boosted the sugar and anthocyanin content at harvest. Extensive transcriptome remodeling was observed in thinned vines 2 weeks after thinning and at ripening. This included the enhanced modulation of genes that are normally regulated during berry development and the induction of a large set of genes that are not usually expressed. Conclusion: Cluster thinning has a profound effect on several important cellular processes and metabolic pathways including carbohydrate metabolism and the synthesis and transport of secondary products. The integrated agronomic, biochemical and transcriptomic data revealed that the positive impact of cluster thinning on final berry composition reflects a much more complex outcome than simply enhancing the normal ripening process.
Project description:Background: Cluster thinning is an agronomic practice in which a proportion of berry clusters are removed from the vine to increase the source/sink ratio and improve the quality of the remaining berries. Until now no transcriptomic data have been reported describing the mechanisms that underlie the agronomic and biochemical effects of thinning. Results: We profiled the transcriptome of Vitis vinifera cv. Sangiovese berries before and after thinning at veraison using a genome-wide microarray representing all grapevine genes listed in the latest V1 gene prediction. Thinning increased the source/sink ratio from 0.6 to 1.2 m2 leaf area per kg of berries and boosted the sugar and anthocyanin content at harvest. Extensive transcriptome remodeling was observed in thinned vines 2 weeks after thinning and at ripening. This included the enhanced modulation of genes that are normally regulated during berry development and the induction of a large set of genes that are not usually expressed. Conclusion: Cluster thinning has a profound effect on several important cellular processes and metabolic pathways including carbohydrate metabolism and the synthesis and transport of secondary products. The integrated agronomic, biochemical and transcriptomic data revealed that the positive impact of cluster thinning on final berry composition reflects a much more complex outcome than simply enhancing the normal ripening process. Total RNA recovered from a pool of berries derived from three control plants (C) was compared to total RNA from a pool of berries derived from three cluster thinned vines (50% of cluster removed) at beginning of véraison (BV), end of véraison (EV) and harvest (H). For each sampling date microarray analyses were conducted for three different biological replicates for treatment.
Project description:Temperature and solar radiation influence Vitis vinifera L. berry ripening. Both environmental conditions fluctuate cyclically on a daily period basis and the strength of this fluctuation affects grape ripening too. Additionally, a molecular circadian clock regulates daily cyclic expression in a large proportion of the plant transcriptome modulating multiple developmental processes in diverse plant organs and developmental phases. Circadian cycling of fruit transcriptomes has not been characterized in detail despite their putative relevance in the final composition of the fruit. Thus, in this study, gene expression throughout 24 h periods in pre-ripe berries of Tempranillo and Verdejo grapevine cultivars was followed to determine whether different ripening transcriptional programs are activated during certain times of day in different grape tissues and genotypes. Results: Microarray analyses identified oscillatory transcriptional profiles following circadian variations in the photocycle and the thermocycle. A higher number of expression oscillating transcripts were detected in samples carrying exocarp tissue including biotic stress-responsive transcripts activated around dawn. Thermotolerance-like responses and regulation of circadian clock-related genes were observed in all studied samples. Indeed, homologs of core clock genes were identified in the grapevine genome and, among them, VvREVEILLE1 (VvRVE1), showed a consistent circadian expression rhythm in every grape berry tissue analysed. Light signalling components and terpenoid biosynthetic transcripts were specifically induced during the daytime in Verdejo, a cultivar bearing white-skinned and aromatic berries, whereas transcripts involved in phenylpropanoid biosynthesis were more prominently regulated in Tempranillo, a cultivar bearing black-skinned berries. Conclusions: The transcriptome of ripening fruits varies in response to daily environmental changes, which might partially be under the control of circadian clock components. Certain cultivar and berry tissue features could rely on specific circadian oscillatory expression profiles. These findings may help to a better understanding of the progress of berry ripening in short term time scales. A total of 54 samples were hybridized. Three different circadian time course series consisted on six time point each. Series corresponded to pericarp of Verdejo grapevine cultivar and berry flesh and skin in separate of Tempranillo cultivar. Three biological replicates were analyzed for each series.