Project description:Drought has become an increasingly important constraint on grapevine sustainability due to global climate change. Vitis riparia, the only grapevine native to the upper Midwest region of the United States, is widely used in scion and rootstock breeding; however, it is not considered drought tolerant. In this study, RNA-Seq data were generated from grapevine root/shoot under WD and well-watered (control (C)) conditions to compare root signaling and shoot responses to water deficit.
Project description:The transition of axillary grapevine buds from paradormancy to endodormancy is an important mechanism for winter survival. Maintenance of paradormancy and transition to endodormancy may be synchronized by factors including phytohormones, genes, transcription factors and other molecular regulators. In the present study we used age matched buds from vines subjected to 28 days of short day (SD; 13h) treatment or continued long day (LD; 15h) photoperiod for high throughput transcriptome profiling.
Project description:Grapevine rupestris stem pitting-associated virus (GRSPaV) is a widespread virus affecting Vitis spp. Although it has established a compatible viral interaction in Vitis vinifera L. without the development of phenotypic alterations, it can occur as distinct variants that show different symptoms in diverse Vitis species. We investigated the changes induced by GRSPaV in V. vinifera cv Bosco, an Italian white grape variety, by combining agronomic, physiological, and molecular approaches, in order to provide comprehensive information about the global effects of GRSPaV. In two consecutive years, this virus caused a moderate decrease in physiological efficiency, yield performance, and sugar content in berries associated with several transcriptomic alterations. Transcript profiles were analysed by microarray techniques in petiole, leaf, and berry samples collected at véraison and by quantitative real-time RT-PCR (qRT-PCR) in a time course carried out at five relevant grapevine developmental stages. Global gene expression analyses showed that transcriptomic changes were highly variable among the different organs and the different phenological phases. GRSPaV triggers some unique responses in the grapevine at véraison, never reported before for other plant-virus interactions, such as an increase in transcripts involved in photosynthesis and CO2 fixation, associated with a moderate reduction in the photosynthesis rate and some defence mechanisms, and to an overlap with responses to water and salinity stresses. We hypothesise that the long co-existence between grapevine and GRSPaV has resulted in the evolution of a form of mutual adaptation between the virus and its host. This study contributes to elucidating alternative mechanisms used by infected plants to contend with viruses.
Project description:Grapevine is a perennial crop often cultivated by grafting a scion cultivar on a suitable rootstock. Rootstocks influence scions, particularly with regard to water uptake and vigor. Therefore, one of the possibilities to adapt viticulture to the extended drought stress periods is to select rootstocks conferring increased tolerance to drought. However, the molecular mechanisms associated with the ability of rootstock/scion combination to influence grape berry metabolism under drought stress are still poorly understood. The transcriptomic changes induced by drought stress in grape berries (cv. Pinot noir) from vines grafted on either 110R (drought tolerant) or 125AA (drought sensitive) rootstock were compared. The experiments were conducted in the vineyard for two years and two grape berry developmental stages (50% and 100 % veraison. The genome-wide microarray approach showed that water stress strongly impacts gene expression in the berries, through ontology categories that cover cell wall metabolism, primary and secondary metabolism, signalling, stress, and hormones, and that some of these effects strongly depend on the rootstock genotype. Indeed, under drought stress, berries from vines grafted on 110R displayed a different transcriptional response compared to 125AA concerning genes related to jasmonate, phenylpropanoid metabolism and PR-proteins. The data also suggests a link between jasmonate and secondary metabolism in water-stressed berries. Overall, genes related to secondary metabolism and jasmonate are more induced and/or less repressed by drought stress in the berries grafted on the drought-sensitive rootstock 125AA. These rootstock-dependent gene expression changes are relevant for berry composition and sensory properties.
Project description:Experimental research on the effects of abiotic stress over grapevine has mainly focused on water shortage. The adaptation of plants to stress is a complex response triggered by cascades of molecular networks involved in stress perception, signal transduction, and the expression of specific stress-related genes and metabolites. Approaches such as array-based transcript profiling allow assessing the expression of thousands of genes in control and stress tissues. Gene expression upon acute (heat and light) and steady (drought) individual stresses and field conditions were compared in two grapevine (Vitis vinifera L.) varieties, Trincadeira (TR) and Touriga Nacional (TN).
Project description:The growth and fruit quality of grapevine are widely affected by abnormal climatic conditions such as extreme temperature. But how grapevine responds to cold stress is still largely unknown. Here we found that VaMyb14, a member of R2R3 Myb transcription factor family, was up-regulated dramatically during cold, drought and salinity treatments in Vitis amurensis, a cold and drought-hardiness wild Vitis species. Overexpression VaMyb14 in Arabidopsis increased antioxidant enzyme activity, especially POD activity, than that of the wild type and decreased the MDA content. A series of ABA metabolism and signal transduction genes in transgenic Arabidopsiswere were up-regulated in microarry results, including several nsLTPs, PP2Cs, RD29B, COR78 and other structural genes, suggesting that VaMyb14 not only affect the ABA signaling pathways, but also activates the CBF-COR independent nsLTP genes. Collectively, these results illustrate that Vitis Myb14 could represent a node of convergence regulating grapevine stress responses, including improve defence induced phytoalexin resveratrol against necrotrophic as well as drought and/or cold stress tolerance, highlighting Myb14 as a potential gene resource in future grapevine breeding.
Project description:The growth and fruit quality of grapevine are widely affected by abnormal climatic conditions such as water deficit. But how grapevine responds to drought stress is still largely unknown. Here we found that VaNAC26, a member of NAC transcription factor family, was up-regulated dramatically during cold, drought and salinity treatments in Vitis amurensis, a cold and drought-hardiness wild Vitis species. Ectopic overexpression of VaNAC26 enhanced the drought and salt tolerances in transgenic Arabidopsis. Higher activities of antioxidant enzymes and the lower concentration of H2O2 and O2- were found in VaNAC26-OE lines than in wild type plants under drought stress. These results indicate that the reactive oxygen species (ROS) scavenging was enhanced by VaNAC26 in transgenic lines. Microarray based transcriptome analysis reveals that genes related to jasmonic acid (JA) synthesis and signaling were up-regulated in VaNAC26-OE lines under both normal and drought conditions. VaNAC26 showed a specific binding ability on NACRS motif, which was broadly existent in the promoter regions of up-regulated genes in transgenic lines. Endogenous JA content was found increased obviously in VaNAC26-OE-2/3 lines. Our data suggests that VaNAC26 responds to abiotic stresses and may enhance the drought tolerance by transcriptional regulation of JA synthesis in Arabidopsis.
Project description:Grapevine rupestris stem pitting-associated virus (GRSPaV) is a widespread virus affecting Vitis spp. Although it has established a compatible viral interaction in Vitis vinifera L. without the development of phenotypic alterations, it can occur as distinct variants that show different symptoms in diverse Vitis species. We investigated the changes induced by GRSPaV in V. vinifera cv Bosco, an Italian white grape variety, by combining agronomic, physiological, and molecular approaches, in order to provide comprehensive information about the global effects of GRSPaV. In two consecutive years, this virus caused a moderate decrease in physiological efficiency, yield performance, and sugar content in berries associated with several transcriptomic alterations. Transcript profiles were analysed by microarray techniques in petiole, leaf, and berry samples collected at véraison and by quantitative real-time RT-PCR (qRT-PCR) in a time course carried out at five relevant grapevine developmental stages. Global gene expression analyses showed that transcriptomic changes were highly variable among the different organs and the different phenological phases. GRSPaV triggers some unique responses in the grapevine at véraison, never reported before for other plant-virus interactions, such as an increase in transcripts involved in photosynthesis and CO2 fixation, associated with a moderate reduction in the photosynthesis rate and some defence mechanisms, and to an overlap with responses to water and salinity stresses. We hypothesise that the long co-existence between grapevine and GRSPaV has resulted in the evolution of a form of mutual adaptation between the virus and its host. This study contributes to elucidating alternative mechanisms used by infected plants to contend with viruses. The study was carried out in a vineyard planted in 2002 in Albenga (Liguria), North-West Italy, where a row was established with the white grape cultivar Bosco (V. vinifera L.). Microarray analysis was carried out on leaves, petioles, and berries collected at véraison (E-L35) in 2010. For each of the six GRSPaV-free and six GRSPaV-infected vines selected for the physiological and agronomical parameters evaluation, we collected 6 leaves (3 basal and 3 apical) with the related petioles and 12 berries from 3 different bunches. Samples from each organ were arbitrary pooled in 3 independent biological replicates and total RNA was extracted according to the method described by Gambino et al. (2008).