1. Plants can adapt to changing environments by adjusting the production and maintenance of diverse sets of bioactive secondary metabolites. To date, the impact of climatic conditions relative to other factors such as soil abiotic factors and herbivore pressure on the evolution of plant secondary metabolites is poorly understood, especially for plant roots.
2. We explored associations between root latex secondary metabolites in 63 Taraxacum officinale populations across Switzerland and climatic conditions, soil abiotic parameters, root herbivore pressure and cytotype distribution. To assess the contribution of environmental effects, root secondary metabolites were measured in F0 plants in nature and F2 plants under controlled greenhouse conditions.
3. Concentrations of root latex secondary metabolites were most strongly associated with climatic conditions, while current soil abiotic factors or root herbivore pressure did not show a clear association with root latex chemistry. Results were similar for natural and controlled conditions, suggesting heritable variation rather than environmental plasticity as underlying factor.
4. Synthesis. We conclude that climatic conditions likely play a major role in the evolution of root secondary metabolites. These results may hint at a novel role of root latex metabolites in tolerance of abiotic stress.

中文翻译：

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根次生代谢产物的遗传变异与近期气候有关

1. 植物可以通过调整各种生物活性次生代谢产物的产生和维持来适应不断变化的环境。迄今为止，人们对气候条件相对于其他因素（例如土壤非生物因素和草食动物压力）对植物次生代谢产物演变的影响了解得很少，尤其是对于植物根系。
2. 我们探索了瑞士63个蒲公英中的根乳胶次生代谢产物与气候条件，土壤非生物参数，根草食动物压力和细胞类型分布之间的关联。为了评估环境影响的贡献，在受控温室条件下，在自然界的F0植物和F2植物中测量了根系次生代谢产物。
3. 根乳胶次生代谢产物的浓度与气候条件最密切相关，而当前的土壤非生物因子或根草食动物压力与根乳胶化学没有明显关联。在自然和受控条件下的结果相似，表明遗传变异而不是环境可塑性是潜在因素。
4. 综合。我们得出结论，气候条件可能在根系次生代谢产物的进化中起主要作用。这些结果可能暗示根乳胶代谢产物在非生物胁迫耐受性中的新作用。