Nitrogen Deposition Enhances Photosynthesis in Moso Bamboo but Increases Susceptibility to Other Stress Factors

作者：Rui Zhang, Jiasheng Wu, Quan Li, Heikki Hänninen, Chunju Peng, Hang Yao, Xinzhang Song, Yeqing Ying · 发表于：Frontiers in Plant Science · 年份：2017 · DOI：10.3389/fpls.2017.01975 · 被引用次数：78 · 研究领域：Plant Water Relations and Carbon Dynamics、Soil Carbon and Nitrogen Dynamics、Plant Stress Responses and Tolerance

Atmospheric nitrogen (N) deposition can increase the susceptibility of vascular plants to other stresses, but the physiological basis of such a response remains poorly understood. This study was designed to clarify the physiological mechanisms and evaluate bioindicators of N deposition impact on vascular plants. Here, we evaluate multiple physiological responses to approximately 4 years of simulated additional N deposition (30 to 90 kg N ha-1 yr-1) on three age-classes (1a, 3a and 5a) of Moso bamboo. A saturating response to the additional N deposition was found both in foliar N concentration and in Pn. However, three- and five-year-old bamboo seemed less tolerant to extremely high N deposition than one-year-old bamboo since they were N saturated at a lower N addition. Furthermore, C/N/P stoichiometric ratios were very sensitive to N deposition in all three-age classes of bamboo, but the responses to N deposition in the various age-classes were diverse. We also found that the highest additional N deposition suppressed stomatal conductance and transpiration rate, suggesting an induced water stress. The stress induced by the high N load was also seen in photochemistry, where it reduced potential and actual photosynthetic use of light energy, diminished photo-protection capacity, and increased risk of the photo-damage. High additional N deposition contributed to a decrease in the foliar soluble protein contents and to an increase in the peroxidase activity (POD). Our study sugge...