NMR Metabolomics of Thrips (Frankliniella occidentalis) Resistance in Senecio Hybrids

Abstract

Western flower thrips (Frankliniella occidentalis) has become a key insect pest of agricultural and horticultural crops worldwide. Little is known about host plant resistance to thrips. In this study, we investigated thrips resistance in F 2 hybrids of Senecio jacobaea and Senecio aquaticus. We identified thrips-resistant hybrids applying three different bioassays. Subsequently, we compared the metabolomic profiles of these hybrids applying nuclear magnetic resonance spectroscopy (NMR). The new developments of NMR facilitate a wide range coverage of the metabolome. This makes NMR especially suitable if there is no a priori knowledge of the compounds related to herbivore resistance and allows a holistic approach analyzing different chemical compounds simultaneously. We show that the metabolomes of thrips-resistant and -susceptible hybrids differed considerably. Thrips-resistant hybrids contained higher amounts of the pyrrolizidine alkaloids (PA), jacobine, and jaconine, especially in younger leaves.Also, a flavanoid, kaempferol glucoside, accumulated in the resistant plants. Both PAs and kaempferol are known for their inhibitory effect on herbivores. In resistant and susceptible F 2 hybrids, young leaves showed less thrips damage than old leaves. Consistent with the optimal plant defense theory, young leaves contained increased levels of primary metabolites such as sucrose, raffinose, and stachyose, but also accumulated jacaranone as a secondary plant defense compound. Our results prove NMR as a promising tool to identify different metabolites involved in herbivore resistance. It constitutes a significant advance in the study of plant-insect relationships, providing key information on the implementation of herbivore resistance breeding strategies in plants.

Fecundity and Survival of Grain Aphid at Various Growth Stages of Waxy and Waxless Triticale

“…There are many examples of negative associations between the fl avonoids present in herbaceous/woody plant species and insects. Leiss et al [48] showed that resistant hybrids contained higher amounts of the fl avonoid kaempferol glucoside. Flavonoids are generally involved in plant resistance to herbivores [49][50][51][52].…”

Application of eco-metabolomics in biological science

“…We successfully applied this approach on different host systems including Senecio as a wild plant [2,3], chrysanthemum [4] and gladiolus as ornamentals and tomato [5] and carrot [6] as vegetables. In all host systems the metabolomic profiles of thrips resistant and susceptible plants were significantly different, leading to different metabolites involved in thrips resistance.…”

Metabolomics: what's new?

“…But for all methods, one should also consider the time needed for extraction and sample preparation, which in the case of GC is far more complicated, as a chemical derivatization step is required, whereas in the case of NMR the extraction can be done with the deuterated NMR solvent. [24][25][26][27][28][29][30][31][32][33] …”

“…These tools can be applied in a broad variety of applications: quality control of medicinal plants (Ephedra spp., [24] Ginkgo biloba [25] ), plant resistance against pests and diseases (Senecio spp., [26] Brassica rapa, [27] Catharanthus roseus, [28] tobacco [29] ), identifi cation of active compounds in medicinal plants (Galphimia glauca [30] ), and chemotaxonomy (Ilex spp., [31] cannabis, [32] Strychnos spp. [33] ).…”