The aim of this review is to combine the knowledge of studies on effects of nutrients on pyrrolizidine alkaloids (PAs) in Senecio with those studies of effects of PAs on herbivores and pathogens in order to predict the effects that nutrients may have on herbivores and pathogens via changes in PAs. We discuss whether these predictions match with the outcome of studies where the effect of nutrients on herbivores and insects were measured. PA concentrations in S. jacobaea, S. vulgaris and S. aquaticus were mostly reduced by NPK fertilization, with genotype-specific effects occurring. Plant organs varied in their response to increased fertilization; PA concentrations in flowers remained constant, while shoot and roots were mostly negatively affected. Biomass change is probably largely responsible for the change in concentrations. Nutrients affect both the variety and the levels of PAs in the plant. The reduced PA concentrations after NPK fertilization was expected to benefit herbivores, but no or negative responses from insect herbivores were observed. Apparently other changes in the plant after fertilization are overriding the effect of PAs. Pathogens do seem to benefit from the lower PA concentrations after fertilization; they were more detrimental to fertilized plants than to unfertilized control plants. Future studies should include the effect of each element of nutrients separately and in combinations in order to gain more insight in the effect of specific nutrients on PA content in Senecio plants.

中文翻译：

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营养物质对千里光植物中吡咯里西啶生物碱的影响及其与食草动物和病原体的相互作用。


本综述的目的是将营养物质对千里光中吡咯里西啶生物碱 (PA) 影响的研究知识与 PAs 对草食动物和病原体影响的研究相结合，以预测营养物质对草食动物和病原体可能产生的影响PA 的变化。我们讨论这些预测是否与测量营养物质对食草动物和昆虫影响的研究结果相符。 NPK 施肥主要降低了 S. jacobaea、S. vulgaris 和 S. Aquaticus 中的 PA 浓度，并产生了基因型特异性效应。植物器官对增加施肥的反应各不相同；花中的 PA 浓度保持恒定，而芽和根大多受到负面影响。生物量的变化可能是浓度变化的主要原因。养分会影响植物中 PA 的种类和水平。 NPK 施肥后 PA 浓度降低预计有利于食草动物，但没有观察到昆虫食草动物的反应或负面反应。显然，受精后植物的其他变化超越了 PA 的影响。受精后，病原体似乎确实受益于较低的 PA 浓度。它们对受精植物的危害比对未受精对照植物的危害更大。未来的研究应包括每种营养素元素单独和组合的影响，以便更深入地了解特定营养素对千里光植物中 PA 含量的影响。