A profiling approach of the natural variability of foliar N remobilization at the rosette stage gives clues to understand the limiting processes involved in the low N use efficiency of winter oilseed rape

摘要: Oilseed rape, a crop requiring high level of nitogen (N) fertilizers, is characterized by low N use efficiency. To identify the limiting factors involved in efficiency winter oilseed response to supply was investigated at vegetative stage 10 genotypes using long-term pulse-chase (15)N labelling and studying physiological processes leaf remobilization. Analysis growth components allowed four profiles be defined. Group 1 an efficient remobilization under conditions but decrease limitation. 2 showed that associated with both supplies despite soluble proteins. In limitation, 3 increase compared not sufficient sustain biomass production similar non-limited plants. Genotypes 4 subjected nitrate were able maintain same as N. The profiling approach indicated enhancement amino acid export protein degradation crucial for improvement. At whole-plant level, fluxes revealed source leaves combined better utilization young leaves. Consequently, enhanced limits loss fallen leaves, this remobilized needs efficiently utilized improve