Transcriptomic response in leaves of two Vitis vinifera L. varieties in field and under greenhouse abiotic stress

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). In the field, only irrigation was used as treatments, thus two treatments were applied: Full irrigated (control) and non irrigated (stress). Irrigation water was applied with drip emitters (4.0 L h-1 for FI) two per vine, positioned 30 cm from the vine trunk. The water was supplied according to the crop’s evapotranspiration (ETc). Samples were taken when the pre dawn leaf water potential was circa -0.7MPa in the NI plants and higher than -0.2MPa in the FI plants. To assess physiological effects of stress treatments: Individual stresses were applied when shoots were 50 to 60 cm high (after circa four months growth). The stresses applied were: W (Water)– stop irrigation until the pre-dawn leaf water potential (Ψw) was -0.9 MPa; L (Light) – 1 hour at 2000µmolm2s-1; H (Heat) – 1 hour at 42ºC