Project description:Somatic variation is a valuable source of trait diversity in clonally propagated crops. In grapevine, which has been clonally propagated worldwide for centuries, important phenotypes such as white berry colour are the result of genetic changes caused by transposable elements. Additionally, epiallele formation may play a role in determining geo-specific (‘terroir’) differences in grapes and thus ultimately in wine. This genomic plasticity might be co-opted for crop improvement via somatic embryogenesis, but that depends on a species-specific understanding of the epigenetic regulation of transposable element (TE) expression and silencing in these cultures. For this reason, we used whole-genome bisulphite sequencing, mRNA sequencing and small RNA sequencing to study the epigenetic status and expression of TEs in embryogenic callus, in comparison with leaf tissue.
Project description:Nebbiolo genome assembly allows surveying the occurrence and functional implications of genomic structural variations in grapevines (Vitis vinifera L.)
Project description:Three grapevines cultivars (Merlot, Cabernet-Sauvignon and Ugni Blanc) were infected by E. lata. The expression profiles of the wood part near the infection point were determined for both infected and non infected plant for each cultivars with Nimblegen microarrays vitis. Three plants were used for biological replicates. Comparisons between infected and non infected conditions allow, for each cultivars, the identifcation of genes which the expression is modified by E. lata.
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: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.
Project description:To elucidate the effect of heat stress and the following recovery on grapevines and identify some regulated genes representing the classical heat stress response and thermotolerance mechanisms, transcript abundance of grapevine (Vitis vinifera L.) were quantified using the Affymetrix Grape Genome oligonucleotide microarray (15,700 transcripts), followed by quantitive Real-Time PCR validation for some transcript profiles. The treatment: heat stress(5h) and the following recovery (18.5h), sampling were conducted at two time respectively. ****[PLEXdb(http://www.plexdb.org) has submitted this series at GEO on behalf of the original contributor, Lijun Wang. The equivalent experiment is VV40 at PLEXdb.]
Project description:Study of gene expression during Plasmopara viticola infection in the resistant Vitis vinifera cultivar 'Regent'. The oomycete fungus Plasmopara viticola (Berk. et Curt.) Berl. et de Toni is responsible for grapevine downy mildew disease. Most of the cultivated grapevines are sensitive to this pathogen, thus requiring intensive fungicide treatments. The molecular basis of resistance to this pathogen is poorly understood. We have carried out a cDNA microarray transcriptome analysis to identify grapevine genes associated with resistance traits. Early transcriptional changes associated with downy mildew infection in the resistant Vitis vinifera cultivar ‘Regent’, when compared to the susceptible cultivar ‘Trincadeira’, were analyzed. Transcript levels were measured at three time-points: 0, 6 and 12 hours post inoculation (hpi). Our data indicate that resistance in V. vinifera ‘Regent’ is induced after infection. This study provides the identification of several candidate genes that may be related to ‘Regent’ defense mechanisms, allowing a better understanding of this cultivar's resistance traits.