The Pyrrolizidine Alkaloids (PAs) are a group of chemicals found in a variety of plant species throughout the world. These toxic alkaloids are distributed mainly in Senecio (Compositae), Crotalaria (Legominosae) and Heliotropium (Boraginaceae) species. Plants containing these alkaloids cause significant mammalian morbidity and mortality, especially in humans. Upon ingestion, metabolic activatio...

This volume of the IARC Monographs considers some traditional herbal medicines, including extracts from certain plants of the genera Aristolochia, Rubia, Morinda and Senecio; some mycotoxins, specifically aflatoxins and fumonisin B1; and two industrial chemicals, naphthalene and styrene. Of these, the Monographs have previously evaluated several of the pyrrolizidine alkaloids that occur in cert...

the pyrrolizidine alkaloids (pas) are a group of chemicals found in a variety of plant species throughout the world. these toxic alkaloids are distributed mainly in senecio (compositae), crotalaria (legominosae) and heliotropium (boraginaceae) species. plants containing these alkaloids cause significant mammalian morbidity and mortality, especially in humans. upon ingestion, metabolic activatio...

THE ECOLOGY OF RAGWORT (SENECIO JACOBAEA L.) A REVIEW Summary: The available literature on ragwort is reviewed. The ecological behaviour of ragwort can be explained by its tendency to act as a colonising plant, which is encouraged by pasture disturbance. Ragwort-infested pasture and closed pasture alternate with each other, and this is influenced by a number of environmental and management fact...

Changes in growth forms frequently accompany plant adaptive radiations, including páramo-a high-elevation treeless habitat type of the northern Andes. We tested whether diverse group of Senecio inhabiting montane forests and páramo represented such growth form changes. We also investigated the role of Andean geography and environment in structuring genetic variation of this group. We sampled 10...

Pyrrolizidine alkaloids (PAs) of the macrocyclic senecionine type are secondary metabolites characteristic for most species of the genus Senecio (Asteraceae). These PAs are deterrent and toxic to most vertebrates and insects and provide plants with a chemical defense against herbivores. We studied the PA composition of 24 out of 26 species of Senecio section Jacobaea using GC-MS. The PA profile...

Hybridization may lead to unique phytochemical expression in plant individuals. Hybrids may express novel combinations or extreme concentrations of secondary metabolites or, in some cases, produce metabolites novel to both parental species. Here we test whether there is evidence for extreme metabolite expression or novelty in F1 hybrids between Senecio aquaticus and Senecio jacobaea. Hybridizat...

Hybridization generates evolutionary novelty and spreads adaptive variation. By promoting outcrossing, plant self-incompatibility (SI) systems also favor interspecific hybridization because the S locus is under strong negative frequency-dependent balancing selection. This study investigates the SI mating systems of three hybridizing Senecio species with contrasting population histories. Senecio...