Project Objectives

The Portuguese Flora is particularly rich in aromatic and medicinal species. Some of these species are endemics, sometimes in vulnerable ecological niches. The knowledge on plant species with potential for agriculture use can contribute for a sustainable exploitation of agricultural lands.
The goals of the project are: 1) study of the chemical diversity of several populations of different aromatic endemic species, to assist in their conservation and management; 2) assessment of genetic fingerprint patterns of multiple populations within each studied species to define genetic diversity and populations structure and correlate the genetic background with the chemical variability of those populations; 3) evaluate the biological activity of the isolated essential oils to determine the endemic species with potential economic interest, and 4) recognition of evolutionary
"units" as source of genotypes, producing bioactive secondary metabolites, for eventual agriculture exploitation.

Abstract

During the last decades the interest on plant based pharmaceuticals has increase all over the world. The same search for natural products has been verified in food and flavour and fragrances industries. Global and national trades for aromatic and medicinal plants are rapidly increasing, representing high economical rises.
The Portuguese Flora is particularly rich in aromatic and medicinal species. From about 3800 species found in the Portuguese mainland and on Azores and Madeira archipelagos, more than 500 are aromatic and/or medicinal, some of these with potential use as an alternative for sustainable agriculture systems or for exploitation of poor agriculture soils. These species belong mainly to Apiaceae, Asteraceae, Lamiaceae, Mirtaceae, Oleaceae, Liliaceae, Rosaceae, Leguminosae, Rutaceae, Hipericaeae, Pinaceae, Cupressaceae, Lauraceae and Malvaceae families. Some of these species are endemics, sometimes in vulnerable ecological niches. The conservation of this biodiversity, together with a sustainable use, should contribute for the settling of human populations on their traditional habitat.
A long-standing challenge in studies on essential oils has been the characterization of factors responsible for the chemical polymorphism recorded within some species. In spite of the chemical polymorphism of some aromatic species, no correlation could be drawn between the edapho-climatic features of the places of collection and the composition of the oils. In the last decade, however, technological advancement has increasingly supported the use of genetics in assessing population diversity and many molecular techniques are now available which allow determining the genetic architecture of a wide variety of closely related individuals.
The search for natural products with biological activity has stimulated the use of essential oils as antimicrobial and antioxidant agents in food products. Together with their flavour properties, essential oils are natural and biodegradable, are considered to have low toxicity towards mammals and can fulfil the functions of more than one of their synthetic substitutes.
The proposed studies will be performed on individual plants, collected from selected populations, at several locations on the Portuguese mainland and on Azores and Madeira archipelagos.
Qualitative and quantitative essential oil analyses will be performed by HRGC and by HRGC-MS, using chiral and achiral columns.
An efficient system for DNA extraction at high yield and with good quality will be improved using young leaves of plants from the different species. Different molecular markers will be tested, namely RAPDs (arbitrary primers) and ISSRs (specific primers for repetitive regions anchored with 2-3 nucleotides at the 3' or 5' end). Several primers, able to detect enough polymorphisms, will be tested to assess genetic diversity of the sample. Correlation between molecular markers data and essential oil profile will be evaluated.
When obtaining the dendrograms, the genetic information of an out-group will be included. Phytochemical and molecular data will be used to evaluate the relationship between habitat fragmentation and genetic variation, aiming to identify the most interesting genotypes in terms of quality of the essential oils produced.
Antimicrobial activity will be evaluated against several bacterial species and filamentous and unicellular fungi. Antioxidant activity will be evaluated using diverse established methods to determine the antioxidant profile of the tested oils. Cytotoxic activity will be evaluated on several mammal and human cell lines.
The over-all information obtained in the several tasks will enable the selection of Portuguese endemic aromatic species that show potential economical interest and that can be used for agricultural exploitation, as an alternative to the traditional crops, particularly in agriculture poor lands.