Effect of contrasted N regimes on the root transcriptome of Medicago truncatula plants cultivated in split root systems and inoculated for 2, 4 and 7 days with Sinorhizobium medicae

The experiment aims to analyze the effect of systemic signaling of plant N demand on the transcriptome of Medicago truncatula roots inoculated with Sinorhizobium medicae MD4 at 2, 4, and 7 days post-inoculation (dpi). We divided the roots systems into two parts; one of them was supplied with nutrient solution with mineral N (10 mM NH4NO3 for N-satisfied plants, 0.5 mM for N-limited plants) whereas the non-N treated part was kept in nutrient solution without mineral N. All roots were inoculated 48h after initiation of the N treatments. To characterize specifically the impact of systemic signaling of N demand, we collected the roots the non-N treated sides of the split roots systems and we isolated total RNA for RNAseq analysis. Root transcriptomes of N-limited and N-satisfied plants were compared at 2, 4 and 7 dpi.