J PLANT NUTR SOIL SC ：中科院成都生物所丨低氮提高云杉氮利用率新机制

NMT是基因功能的活体检测技术，已被103位诺贝尔奖得主所在单位，及北大、清华、中科院使用。

期刊：Journal of Plant Nutrition And Soil Science

主题：低氮提高云杉氮利用率新机制

标题：Morphological and physiological responses of Picea asperata to different nitrogen availability and pH

影响因子：2.057

检测指标：NH4+、NO3-、H+流速

检测样品：云杉幼苗根系

NH4+、NO3-、H+流实验处理方法：

50 or 1000 mM NH4NO3 with pH5 or pH7，发芽后生长8周用于测定

NH4+、NO3-、H+流实验测试液成份：
0.1mM KCl, 0.1mM CaCl2, pH5 or pH7

作者：中科院成都生物所尹春英、唐波

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）

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：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。

结果表明：无论pH是5或7，低N的NH4+吸收速率高于高N；不同pH的NH4+吸收速率并无显著差异（图b）。低N的NO3-吸收速率同样高于高N，pH   5时两种N的NO3-吸收速率均低于pH7（图c）。相同pH条件下，低N的H+外排速率高于高N；同样N水平下，不同pH的H+外排无显著差异（图d）。由此可见，云杉通过扩大吸收区域和提高吸收速率等形态和生理的一系列调控从而适应土壤中的限制性N环境。