Metabolomic study of diurnal variation on pyrrolizidine alkaloid from Jacobaea sp. hybrids

4^th International Conference and Exhibition on Metabolomics & Systems Biology

April 27-29, 2015 Philadelphia, USA

Tri R Nuringtyas1, Robert Verpoorte2, Peter G L Klinkhamer2, Young Hae Choi2 and Kirsten A Leiss2

Posters-Accepted Abstracts: Metabolomics

Abstract :

Recently, metabolomics have been applied to study the plant-host resistance. The cause of variation in results could be from biological variation rather than technical issues related to analytical platforms. Little attention has been paid to harvested time, although differences in the metabolomes may depend on day time. We investigated the effect of harvesting time on metobolomes of two hybrids of Jacobaea vulgaris and Jacobaea aquatica differing in their amount of the pyrrolizidine alkaloid jacobine N-oxide. Leaves of genotypes A and B (high and low levels of jacobine, respectively) were sampled daily at three harvest times: Morning (10:00 h), afternoon (15:00 h) and evening (19:00 h) during five consecutive days. Samples were subjected to 1H NMR. Qualitative and quantitative differences in metabolic profiles were analysed by multivariate analysis followed by a three-way ANOVA. The leaf metabolome was only affected by the harvesting time of the day, while the harvesting day had no influence. Independently from the genotype, senecionine N-oxide and succinic acid were accumulated in the morning while sugars and formic acid were accumulated towards the evening. For most compounds in the diurnal variation was similar, but jacobine N-oxide was found to have a significant interaction with both harvest time and genotype. Genotype A showed a much stronger accumulation in the morning. The results suggest that harvest time is an important factor in metabolomics results. Samples from the same genotypes collected at different times of the day may cause a metabolic variation, leading to equivocal conclusions.