Metabolomics in plant taxonomy: The Arnica model

Author(s)

Madeleine Ernst

• Document type: Master's Dissertation
• Press: Ribeirão Preto.
• Institution: Universidade de São Paulo (USP). Faculdade de Ciências Farmacêuticas de Ribeirão Preto (PCARP/BC)
• Defense date: 2013-08-23

Examining board members

Norberto Peporine Lopes; Ian Castro Gamboa; Paul Gates

• Advisor: Norberto Peporine Lopes

Abstract

Plant taxonomy is the science of description, identification, nomenclature and classification of plants. The development of new techniques that can be applied in this field of research are essential in order to assist informed and efficient decision-making about conservation of biodiversity hotspots. In this master\'s thesis a protocol for metabolic fingerprinting by matrix-assisted laser desorption/ionisation mass spectrometry (MALDI-MS) with subsequent multivariate data analysis by in-house algorithms in the R environment for the classification of 24 plant species from closely as well as from distantly related families and tribes was developed. Metabolic fingerprinting forms part of metabolomics, a research field, which aims to analyse all metabolites, i.e., the metabolome in a given system (cell, tissue, or organism) under a given set of conditions. Compared to other metabolomics techniques MALDI-MS shows potential advantages, mainly due to its rapid data acquisition. All analysed species were collected in areas of the Brazilian Savanna (Cerrado), which was classified as \"hotspot for conservation priority\". The complexity and importance of correct taxonomic classification is illustrated on the example of the genus Lychnophora, of which several species also have been included into analysis. In Brazil species of this genus are popularly known as \"arnica da serra\" or \"falsa arnica\". Similarities to taxonomic classification could be obtained by the proposed protocol and data analysis. However there is still a long way to go in making metabolic fingerprinting by MALDI-MS a standard procedure in taxonomic research. Several difficulties that are inherent to sample preparation, analysis of plant\'s metabolomes by MALDI-MS as well as data analysis are highlighted in this study and might serve as a basis for further research. (AU)

• FAPESP's process: 11/05215-0 - Metabolomics in plant systematics: the arnica model
• Grantee: Madeleine Ernst
• Support Opportunities: Scholarships in Brazil - Master