Liu Liling, Chen Ziyan, Gou Xiaomei, Hou Lingcao, Liang Chenglong, Jiao Huan, Kong Weibo, Qiu Liping, Wang Xiang, Wei Xiaorong
College of Natural Resources and Environment, Northwest A&F University, Yangling, 712100, China; State Key Laboratory of Soil Erosion and Dryland Agriculture on the Loess Plateau, Northwest A&F University, Yangling, 712100, China.
State Key Laboratory of Soil Erosion and Dryland Agriculture on the Loess Plateau, Northwest A&F University, Yangling, 712100, China.
J Environ Manage. 2025 Feb;375:124162. doi: 10.1016/j.jenvman.2025.124162. Epub 2025 Jan 23.
Nitrogen (N) fixing legumes typically enhance the ability of coexisting non-N-fixing species to resist disease and drought, but whether legumes enhance their ability to resist salt stress remains unknown, restricting our ability to explore the potential of legumes to rehabilitate salt-affected ecosystems. We conducted a simulation experiment to examine whether and how legumes influence the response of coexisting grass to salt stress. We compared the effects of salt stress on the plant biomass, root cell viability, antioxidant enzyme activities, soil extracellular enzyme activities and microbial functional gene abundances associated with N and phosphorus (P) cycling between pure grass communities and legume-grass mixtures. We found that salt stress decreased grass biomass and the abundance of most N and P cycling genes in rhizosphere soils. However, these negative effects were smaller in legume-grass mixtures than in pure grass community. Additionally, salt stress increased the activities of soil N and P cycling enzymes, with greater positive effects observed in legume-grass mixtures than in the pure grass community. The structural equation modelling results showed that the most direct and indirect path coefficients of salt stress effects on biomass were smaller in legume-grass mixtures than in the pure grass community. Our findings provide direct evidence that legumes can reduce the negative impact of salt stress on co-existing grass community, highlighting the potential of including legumes with high N fixation abilities to restore salt-affected ecosystems.
固氮豆科植物通常会增强共存的非固氮物种抵抗疾病和干旱的能力，但豆科植物是否能增强其抵抗盐胁迫的能力尚不清楚，这限制了我们探索豆科植物修复受盐影响生态系统潜力的能力。我们进行了一项模拟实验，以研究豆科植物是否以及如何影响共存草类对盐胁迫的反应。我们比较了盐胁迫对纯草群落和豆科植物 - 草类混合物之间与氮（N）和磷（P）循环相关的植物生物量、根细胞活力、抗氧化酶活性、土壤胞外酶活性以及微生物功能基因丰度的影响。我们发现盐胁迫降低了草类生物量以及根际土壤中大多数氮和磷循环基因的丰度。然而，这些负面影响在豆科植物 - 草类混合物中比在纯草群落中更小。此外，盐胁迫增加了土壤氮和磷循环酶的活性，在豆科植物 - 草类混合物中观察到的积极影响比在纯草群落中更大。结构方程模型结果表明，盐胁迫对生物量影响的最直接和间接路径系数在豆科植物 - 草类混合物中比在纯草群落中更小。我们的研究结果提供了直接证据，表明豆科植物可以减少盐胁迫对共存草类群落的负面影响，突出了纳入具有高固氮能力的豆科植物来恢复受盐影响生态系统的潜力。
