Comprehensive untargeted metabolomics and screening of insect-plant interactions of Lychnnophorinae subtribe (Asteraceae: Vernonieae)

Author(s)

Maria Elvira Poleti Martucci

• Document type: Doctoral Thesis
• Press: Ribeirão Preto.
• Institution: Universidade de São Paulo (USP). Faculdade de Ciências Farmacêuticas de Ribeirão Preto
• Defense date: 01 fev. 2016

Examining board members

Leonardo Gobbo Neto; Norberto Peporine Lopes; Paulo Henrique Gorgatti Zarbin

• Advisor: Leonardo Gobbo Neto

Abstract

The subtribe Lychnophorinae occurs in the Cerrado domain of the Brazilian Central Plateau. The relationships among its recognized genera, as well as the relationships between Lychnophorinae and other subtribes belonging in tribe Vernonieae have been recently investigated upon a phylogeny based on molecular and morphological data. In addition, a preliminar overview of insect diversity in Brazilian Cerrado suggests that it may harbor a considerable fraction of the neotropical. We here report the use of a comprehensive untargeted metabolomics approach, combining LC-MS and GC-MS data together, followed by multivariate analyses aiming to assess the congruence between metabolomics data and the phylogenetic hypothesis, as well as its potential as a chemotaxonomic tool. Also we report the use of untargeted metabolomics approach aiming to assess insect-plant interactions. We analyzed 78 species by GC-MS and LC-MS in both positive and negative ionization modes. The metabolic profiles obtained for these species were treated in MetAlign and in MSClust and the matrices generated were combined and used in SIMCA for hierarchical cluster analyses (HCA), principal component analyses (PCA) and orthogonal partial least square discriminant analysis (OPLS-DA). The insects were collected quarterly and analyzed by the same analytical methods as plants. Results show that metabolomics analyses are mostly congruent with the phylogenetic hypothesis especially at lower taxonomic levels. Therefore, our results suggest that data generated by metabolomics approaches provide valuable evidence for chemotaxonomical studies of Lychnophorinae subtribe, in particular as primary data for phylogenetic reconstruction of lineages as genera. Regarding to insects, it was possible to observe significative correlations between some insects and their host plants. In these samples, were able to identify triterpenes, flavonoids and sesquiterpene lactones. (AU)

• FAPESP's process: 12/16646-4 - Metabolomics and screening of plant-insect interactions of plants from the subtribe Lychnophorinae (Asteraceae)
• Grantee: Maria Elvira Poleti Martucci
• Support type: Scholarships in Brazil - Doctorate