Xu Lingjie, Li Yanhui, Dai Xiaoyu, Jin Xueyu, Zhao Qiannai, Tian Boyu, Zhou Yong
Hebei Agricultural University, Baoding, China.
BMC Plant Biol. 2025 Jan 3;25(1):10. doi: 10.1186/s12870-024-05883-y.
Nitrogen (N) deposition has become a major driving factor affecting the balance of terrestrial ecosystems, changing the soil environment, element balance and species coexistence relationships, driving changes in biodiversity and ecosystem structure and function. Human-induced nitrogen input leads to a high NH/ NO ratio in soil. However, relatively few studies have investigated the effects of different nitrogen sources on forest plant-microbial symbionts. In this study, the effects of four nitrogen sources, N free, NHCl, L-glutamic acid, and Na(NO) (N-, NH-N, Org-N, and NO-N) on four fungal species, Suillus granulatus (Sg), Pisolithus tinctorius (Pt), Pleotrichocladium opacum (Po), and Pseudopyrenochaeta sp. (Ps), which were isolated from the roots of Pinus tabulaeformis, were studied in vitro. The effects of inoculation with the four fungi on the growth performance, nutrient uptake and nitrogen metabolism-related enzymes of Pinus tabuliformis under different nitrogen source conditions were subsequently studied.
The biomass and N concentration of the Sg and Po strains were the highest under the NO-N treatment, while the biomass and N concentration of the Pt and Ps strains were significantly greater under the NH-N and NO-N treatments than under the Org-N and N- treatments. All four fungi could effectively colonize the roots of P. tabuliformis and formed a symbiotic relationship with it. Under all nitrogen conditions, the inoculation of the four fungi had positive effects on the growth, root development and nutrient concentration of the P. tabuliformis seedlings. Under the Org-N and NO-N treatments, the nitrate reductase (NR) activity of the inoculated plants was significantly greater than that of the noninoculated control (CK) plants. Under all nitrogen conditions, the glutamine synthetase (GS) activity of the inoculated plants was significantly greater than that of the CK plants.
The four fungi can establish good symbiotic relationships with P. tabuliformis seedlings and promote their growth and development under different nitrogen source treatments.
氮沉降已成为影响陆地生态系统平衡的主要驱动因素，改变了土壤环境、元素平衡和物种共存关系，推动了生物多样性以及生态系统结构和功能的变化。人为导致的氮输入致使土壤中铵态氮/硝态氮比例偏高。然而，相对较少的研究探讨了不同氮源对森林植物 - 微生物共生体的影响。在本研究中，体外研究了四种氮源，即无氮、氯化铵、L - 谷氨酸和硝酸钠（N -、铵态氮 - N、有机氮、硝态氮 - N）对从油松根部分离出的四种真菌，即颗粒牛肝菌（Sg）、彩色豆马勃（Pt）、暗褐网柄牛肝菌（Po）和拟茎点霉属（Ps）的影响。随后研究了接种这四种真菌对不同氮源条件下油松生长性能、养分吸收和氮代谢相关酶的影响。
在硝态氮 - N处理下，Sg和Po菌株的生物量和氮浓度最高，而Pt和Ps菌株在铵态氮 - N和硝态氮 - N处理下的生物量和氮浓度显著高于有机氮和无氮处理。所有四种真菌都能有效定殖于油松根部并与之形成共生关系。在所有氮条件下，接种这四种真菌对油松幼苗的生长、根系发育和养分浓度均有积极影响。在有机氮和硝态氮 - N处理下，接种植物的硝酸还原酶（NR）活性显著高于未接种对照（CK）植物。在所有氮条件下，接种植物的谷氨酰胺合成酶（GS）活性显著高于CK植物。
这四种真菌能与油松幼苗建立良好的共生关系，并在不同氮源处理下促进其生长发育。
