Swainsonine

Climate change‐induced grassland degradation has exacerbated the spread of toxic plants, yet many potentially toxic species remain overlooked, undermining rangeland management and causing significant economic losses. Quantifying the toxicity and distribution of potential toxic plants under climate change is critical for mitigating biogeographic risks. As a case study, taking Sphaerophysa salsula , a leguminous plant distributed in Asia and the Americas, historically utilized for erosion control but recently associated with livestock poisoning, this research integrated toxicity identification, species distribution modeling (SDM), and risk assessment to evaluate its biogeographic threats in China. Results suggested for the first time that S. salsula can function as a high‐toxicity (chemotype 1) locoweed due to swainsonine (mean content 0.373%), produced by its endophyte Alternaria oxytropis (23.46 pg/ng), which is implicated in locoism‐like syndromes in livestock. The Maximum Entropy model identified temperature annual range (43.22°C), mean temperature of the driest quarter (−6.29°C), and soil pH (8.61) as key distribution drivers. Currently, suitable habitats are concentrated in Northern China (Xinjiang, Inner Mongolia, Ningxia). By the 2070s, these habitats are projected to decline by 6.3%–9%, shifting westward toward pastoral regions. Risk assessments integrating grazing intensity revealed high‐risk zones in Gansu, Ningxia, and Inner Mongolia, with future scenarios predicting declining risks in eastern Inner Mongolia but increasing threats in western Tibet. These findings clarify S. salsula 's toxic mechanism and biogeographic risks, providing a framework for targeted management of overlooked toxic plants under climate change.

Locoweed refers to poisonous plants in the genus Oxytropis and Astragalus and distributed widely throughout the World. Foraging livestock can be poisoned through ingestion of locoweed resulting in economic loss. Swainsonine is the main toxic component of locoweed and chemically belongs to indolizidine alkaloids. The mechanism of the swainsonine-induced toxic responses is not well understood. In this study, we performed comprehensive transcriptomic analysis examining the differential gene expression in primary renal tubular epithelial cells (RTECs) of rats treated with swainsonine. Our analysis uncovered differential expressions of ncRNA(DEncRNAs) and mRNAs(DEmRNAs) in response to swainsonine treatment. Significant pathways enriched by differential genes through transcriptome association analysis were xenobiotic metabolism-cytochrome P450, bile secretion, and steroid biosynthesis, etc. Notably, aryl hydrocarbon receptor (AhR)-regulated xenobiotic pathway is significantly activated as evidenced by the coordinated up-regulation of the classic AhR-regulated battery of genes Cyp1a1, Cyp1b1, AhRR, Nqo1, and phase II enzyme Gsta2, Gsta3, Gsta5. These results suggest that swainsonine is metabolically detoxified through the AhR regulated xenobiotic detoxification pathway and furthermore, our finding also suggest an intervention strategy to ameliorate to locoweed poisoning through activation of AhR-regulated deoxification pathway.