Effects of simulated nitrogen deposition on Phyllostachys edulis (Carr.) seedlings under different watering conditions: is seedling drought tolerance related to nitrogen metabolism?

Aims Drought stress is an important limiting factor ofplant performance, and how it interacts with increasingnitrogen (N) deposition to affect seedling developmentrequires further investigation. This study addresses thecombined effects of N deposition and drought ongrowth and physiological attributes of Phyllostachysedulis (Carr.) seedlings.Methods Seedling growth attributes and nitrogen me-tabolism indicators were evaluated after the fast-growing period in the presence of four simulated Ndeposition rates (control, 0 kg-ha-'.yr'; low N,30;medium N, 60; high N, 90) and two watering conditions(normal,75土5% of field capacity; or drought,35士5%).Results Drought stress significantly inhibited P. edulisseedling growth and N metabolism. Under normalwatering conditions,greater simulated N depositionwas associated with higher seedling component mass,free amino acid and soluble protein content in leaves,and enzyme activity related to N metabolism.