In this project a proteomic comparative analysis was used to analyse the changes induced by different nitrate availability in roots of M4 grapevine rootstock. Plants, previously adapted to hydroponic condition, were grown for 5 weeks, afterwards nitrogen was removed from the growing medium for eight days to obtain N-starved plants. After this period, the analysis compared plants maintained in absence of nitrogen with plants exposed to 10 mM nitrate for 30 hours.