英文摘要

Soil nitrogen (N) availability and pH are two determinants affecting plant growth, both of which are influenced by long‐term N deposition. However, the physiological mechanism of plants response to the changes in soil N availability and pH are not fully understood.

To investigate the response of Picea asperata to both factors, seedlings of P. asperata were exposed to 50 or 1000 µM NH4NO3 with pH 5 or pH 7. In the current study, P. asperata, regardless of N availability and pH in growth medium, exhibited invariably a urn:x-wiley:14368730:media:jpln201900103-math-0001 preference. Lower root biomass, root : shoot mass ratio, total root length and area, and root vitality were detected in high N condition compared to those in low N supply, corresponding well to lower net influxes of urn:x-wiley:14368730:media:jpln201900103-math-0002 and urn:x-wiley:14368730:media:jpln201900103-math-0003 at the root surface in both pH treatments. These results indicate that P. asperata may employ an active‐forge strategy to exploit nutrient resources for growth under low N availability, probably by increased below‐ground carbon allocation and net influxes of urn:x-wiley:14368730:media:jpln201900103-math-0004 and urn:x-wiley:14368730:media:jpln201900103-math-0005.

Although low pH, to some extent may generate more malondialdehyde, P. asperata would enhance pH tolerance by increased detoxification, i.e., antioxidant enzymes (peroxidase), free proline and soluble protein as well as improved carbohydrate status (i.e., soluble sugar and starch).

中文摘要（谷歌机翻译）

土壤氮（N）的有效性和pH是影响植物生长的两个决定因素，这两个因素均受长期氮沉降的影响。但是，尚未完全了解植物对土壤氮素利用率和pH值变化的生理机制。

为了研究云杉对两种因素的响应，将云杉幼苗暴露于50或1000 µM NH4NO3，pH 5或pH 7。展示了urn：x-wiley：14368730：media：jpln201900103-math-0001偏好设置。与低氮供应相比，高氮条件下根系生物量，根：茎总质量比，总根长和面积以及根系活力较低，这与：x-wiley：14368730：培养基的净入渗量较低相对应。在两种pH处理中，根表面的jpln201900103-math-0002和urn：x-wiley：14368730：media：jpln201900103-math-0003这些结果表明，P。asperata可能采用主动锻造策略来开发养分资源，以在低氮可利用性下进行生长，这可能是由于地下碳分配增加以及骨净流入：x-wiley：14368730：media：jpln201900103-math -0004和urn：x-wiley：14368730：media：jpln201900103-math-0005。

尽管低pH值在一定程度上可能产生更多的丙二醛，但曲霉假单胞菌会通过增加解毒作用（即抗氧化酶（过氧化物酶），游离脯氨酸和可溶性蛋白以及改善的碳水化合物状态（即可溶性糖和淀粉））提高pH耐受性。