Project description:Plants regenerated from tissue culture frequently show somaclonal variation. In this study we compared the transcriptomic and epigenetic state of embryogenic callus of grapevine with leaves from mature grapevine plants. In particular, we focussed on the expression of transposable elements and changes in siRNA abundance and genome-wide methylation in these tissues.
Project description:Plants regenerated from tissue culture frequently show somaclonal variation. In this study we compared the transcriptomic and epigenetic state of embryogenic callus of grapevine with leaves from mature grapevine plants. In particular, we focussed on the expression of transposable elements and changes in siRNA abundance and genome-wide methylation in these tissues.
Project description:Plants regenerated from tissue culture frequently show somaclonal variation. In this study we compared the transcriptomic and epigenetic state of embryogenic callus of grapevine with leaves from mature grapevine plants. In particular, we focussed on the expression of transposable elements and changes in siRNA abundance and genome-wide methylation in these tissues.
Project description:Downy mildew, caused by the obligate biotrophic oomycete Plasmopara viticola, is one of the most destructive grapevine diseases worldwide, constituting a major challenge to viticulture. Because an increasing number of pesticides are removed from market due to their impact on human health and/or the environment, there is an increasing need for alternative strategies to control fungal diseases. Silica nanoparticles (SiO2 NPs) and Frangula anlus extract (Fa) are emerging as promising tools for sustainable plant disease management. While their ability to enhance disease resistance has been demonstrated in several crop species, their potential in grapevine (Vitis vinifera) remains poorly investigated. In this study, foliar application of SiO2 NPs and Fa significantly reduced P. viticola infection in grapevine under both controlled and field conditions. Among multiple assays to characerize their effects, transcriptomic response of SiO2 NP-treated and Fa-Treated, infected and non-infected leaves were evaluated and compared to transcriptomic response of acibenzolar-S-methyl (B) treatment, a well known plant-defence activator. Overall, these findings provide new insights into SiO2 NP-induced and Fa-induced responses in grapevine and highlight their potential for sustainable disease management.
Project description:Oxidative stress can arise when in vitro propagated plants developed under low light conditions are exposed to high light during transfer to ex vitro conditions. In such a situation, among the many potential stresses to which the transferred plant can be exposed, oxidative stress is commonly experienced, most likely brought about by absorption of light energy in excess of that required for very low levels of photosynthetic metabolism. In vitro propagated grapevine when transferred to ex vitro conditions with a 4 fold increase in PPFD shows an initial inhibition of PET accompanied by an accumulation of H2O2, suggesting a signal for the upregulation in gene expression and antioxidant enzyme activity, which peaked at 48h after transfer of in vitro grapevine to ex vitro growing conditions. When in vitro propagated plants are exposed to high light upon transfer to ex vitro oxidative stress symptoms occur. To determine whether the underlying pathways activated at the transfer of in vitro grapevine to ex vitro conditions reflect the processes occurring upon light stress we used microarrays.
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: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: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:Oxidative stress can arise when in vitro propagated plants developed under low light conditions are exposed to high light during transfer to ex vitro conditions. In such a situation, among the many potential stresses to which the transferred plant can be exposed, oxidative stress is commonly experienced, most likely brought about by absorption of light energy in excess of that required for very low levels of photosynthetic metabolism. In vitro propagated grapevine when transferred to ex vitro conditions with a 4 fold increase in PPFD shows an initial inhibition of PET accompanied by an accumulation of H2O2, suggesting a signal for the upregulation in gene expression and antioxidant enzyme activity, which peaked at 48h after transfer of in vitro grapevine to ex vitro growing conditions. When in vitro propagated plants are exposed to high light upon transfer to ex vitro oxidative stress symptoms occur. To determine whether the underlying pathways activated at the transfer of in vitro grapevine to ex vitro conditions reflect the processes occurring upon light stress we used microarrays. Leaves were harvested from in vitro grown plants immediately prior to transfer to ex vitro condition and 48h after transfer to compare gene expression before and after exposure of these plants to the high light conditions typical of ex vitro growth.