Chen Haoran, Renault Sylvie, Markham John
Department of Biological Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada.
Plants (Basel). 2022 Jul 16;11(14):1860. doi: 10.3390/plants11141860.
The mining of the oil sands region of Canada's boreal forest creates disturbed land with elevated levels of salts. Understanding how native plants respond to salt stress is critical in reclaiming these lands. The native species, subsp. forms nitrogen-fixing nodules with , and ectomycorrhizae with a number of fungal species. These relationships may make the plant particularly well suited for restoring disturbed land. We inoculated subsp. with and and exposed the plants to 0, 50, or 100 mM NaCl for seven weeks. -inoculated plants had increased biomass regardless of salt exposure, even though salt exposure reduced nitrogen fixation and reduced the efficiency of nitrogen-fixing nodules. The nitrogen-fixing symbiosis also decreased leaf stress and increased root phosphatase levels. This suggests that N-fixing plants not only have increased nitrogen nutrition but also have increased access to soil phosphorus. Mycorrhizae did not affect plant growth but did reduce nodule numbers and nodule efficiency. These results suggest that the nitrogen-fixing trait is more critical than mycorrhizae. While salt stress inhibits nitrogen-fixing symbiosis, plants still benefit from nitrogen fixation when exposed to salt.
加拿大北方森林油砂区的开采造成了土地扰动，盐分水平升高。了解本土植物如何应对盐胁迫对于这些土地的复垦至关重要。本土物种亚种与形成固氮根瘤，并与多种真菌物种形成外生菌根。这些关系可能使该植物特别适合于恢复受扰动的土地。我们给亚种接种了和，并将这些植物暴露于0、50或100 mM NaCl环境中7周。接种的植物无论是否暴露于盐分环境，生物量都有所增加，尽管盐分暴露会降低固氮作用并降低固氮根瘤的效率。固氮共生关系还降低了叶片胁迫并提高了根系磷酸酶水平。这表明固氮植物不仅增加了氮素营养，而且增加了获取土壤磷的能力。菌根对植物生长没有影响，但确实减少了根瘤数量和根瘤效率。这些结果表明，固氮特性比菌根更为关键。虽然盐胁迫会抑制固氮共生关系，但植物在暴露于盐分环境时仍能从固氮作用中受益。
