The aim of our project is to develop a phenotyping tool using the low field nuclear magnetic resonance (NMR) relaxometry in order to assess the physiological performance of plant leaf tissue in relation with nutrient remobilization processes from senescing sources to developing sinks searching for an integrated evaluation of nitrogen (N) and water use efficiencies. NMR relaxation time measurements have been used in several studies to investigate leaf cells and signals obtained have been described by a multi-exponential behavior reflecting water status and interaction between water and macromolecules in different cell compartments. In this study we used NMR to investigate a relationship between the transverse relaxation time (T2) and leaf senescence in oilseed rape plant. Measurements were realized on 94 samples at different senescence stages, characterized by well described biochemical and molecular markers such as SAG/CAB gene expression, chlorophyll & starch content, water status. Carbon (C) & N reallocation was followed by sugar and aminoacid metabolic profiles while cellular changes were characterized by light microscopy & TEM. T2 measurements were performed on a 20 MHz spectrometer using CPMG sequence. Relaxation decays of the CPMG sequence in all leaf samples were described by 3 to 4 components corresponding to specific cell compartments. We were able to establish correlation between T2 signature and leaf senescing status offering perspectives for a valuable phenotyping tool. Our aim is now to associate change in T2 with subcellular structural re-organization together with metabolite release as C and N ressources and to see how environmental stresses (combining N and water depletion) affect this signal.