Exploring native species of Argentina in York?building bridges

ANA SCOPEL,; ELIZABETH MOYANO; SILVA M.P,

York

Seminario; Labmeeting; 2018

University of York

Plants have evolved a myriad of adaptive strategies that allow them to cope with environmental stress. The production of secondary metabolites by plants is directly linked to the defense against stressors, both abiotic and biotic, and may be triggered by developmental and environmental cues. In this sense, the characterization and identification of a plant´s metabolome may provide relevant information on how metabolism is regulated by the environment, and the role that secondary metabolites play in the maintenance of natural populations. In the genus Flourensia, previous studies have shown the potential of different species as sources of biologically active metabolites, with an ample range of activities that relates to the functional groups to which they belong. One of our research lines with native species focus on the identification of ecologically relevant and potentially useful plant metabolites for the agroindustry. In F. Campestris (FC) y F. Oolepis (FO) we have isolated and identified a novel sesquiterpene, the (-) hamanasic acid A (7-carboxy-8-hydroxy-1(2), 12(13)-dien-bisabolene ((-)AHA)), that proved to have a potent allelopathic effect and selectivity in bioassays with cultivated and weed species. Since FC, FO and F. Riparia (FR) are naturally distributed along an environmental gradient, we were interested in analyzing the variability in the production of secondary metabolites in leaves and stems, along this environmental gradient. We used metabolomic profiling through Py-CGMS and multivariate analysis technique to discriminate plant samples collected from natural populations in Córdoba (FC y FO) and Salta (FR) provinces. Dried and powdered from leaves and stems material from FC, FO and FR was used. The analytical setup consisted of an oven pyrolyzer equipped with an auto sampler (PY-2020iD and AS-1020E, FrontierLabs, Japan) connected to a GC/MS system (Agilent, 7890A/5975C, Agilent Technologies AB, Sweden). The pyrolysis oven was set to 450 ◦C, the interface to 340 ◦C and the injector to 320 ◦C. The injector was operated with a split ratio of 16:1, with helium as the carrier. After one minute the gas saver mode was switched on to vent away pyrolysate bleed of the sample remaining in the pyrolyzer oven. The pyrolysate was separated on a DB-5MS capillary column (30 m × 0.25 mm i.d., 0.25 mm film thickness; J&W, Agilent Techologies AB, Sweden). The GC temperature program started at 40 ◦C and was increased by 32 ◦C min−1 to 100 ◦C, by 6 ◦C min−1 to 120 ◦C, by 15 ◦C min−1 to 250 ◦C and finally by 32 ◦C min−1 to 320 ◦C where the temperature was kept for 3 min which resulted in a total run time of 19 min. The interface to the MS was kept at 280 ◦C. The mass spectrometer with a quadrupolar type analyzer scanned the range from m/z 35 to m/z 250 resulting in a scan rate of 6.22 scans s−1. The mass spectrometer was operated at unit mass resolution. The bucket data was mean center prior chemometrics analysis and the PCA was performed using a total of three principal components -accounting for 98.3% of total variance (p > 0.05).Tendency of grouping based on species location (Córdoba and Salta). The loading plot revealed discriminatory metabolites to be present in high levels in leaves of FC, FO and FR, particularly Terpenes.