Overexpressing Vitis vinifera YSK₂ dehydrin in tobacco improves plant performance

The constitutive expression of a Vitis vinifera dehydrin (DHN) of the YSK₂ type (VvDhn) allowed for a more vigorous growth in transgenic tobacco plants than in wild-type (WT). In vitro, a very distinct germination kinetics and root development profile was observed both under optimal and stress conditions (control, mannitol, NaCl). Transgenic lines outperformed WT in germination success and precocity and root length. Furthermore, transgenic lines were able to germinate under 300 mM mannitol. Adult tobacco plants expressing VvDhn also displayed improved tolerance to both drought and salt stresses. The VvDhn lines under these constraints were significantly better than WT in terms of biomass and leaf number. Moreover, higher capacities to recover from drought were revealed. However, the major effect the VvDhn over-expression was observed under non limiting conditions. VvDhn interfered with the development program leading to higher biomass production (leaf, shoot and root) and to the production of higher number of leaves. The VvDhn gene show great promise for grapevine genetic improvement to drought and salinity tolerance. VvDhn gene can be used to screen and/or design for new grapevine rootstocks that together with viticultural management programs has the potential to cope successfully with a more adverse and unpredictable climate, which is highly demand by community.