School of Science and Health Seminar

You are cordially invited to attend a seminar to be presented by Professor Laurent Legendre, University of Lyon, France, followed by drinks and nibbles.

Seminar Abstract: Numerous lavender and sage species (family Lamiaceae) are widely used by Mediterranean countries as traditional medicine, aromatherapy agent or culinary herb. Volatile terpenes are among the main bioactive chemical ingredients of these plants. They accumulate in little essential oil droplets on the surface of secretory trichome hairs on the plant calices and leaves. One of the most fascinating aspects of these substances is their prodigious diversity among, and even within, plant species. In order to understand the molecular basis of such diversity in lavender and sage species, 194 volatile terpenes accumulated by 43 lavender taxons were analysed and characterised. The influence of inflorescence development on the blend of accumulated volatile terpenes was then studied in two species of lavender of economic interest, L. angustifolia and L. x intermedia. Finally, emphasis was placed on terpene synthases, a family of enzymes responsible for carbon skeleton formation, a key step during terpene biosynthesis. Terpene synthases catalysing the synthesis of major mono-, sesqui- and diterpenes in 3 chemotypes of Spanish lavender (section Stoechas) and in clary sage were cloned and functionally characterised. Taken together, these results demonstrate that the particular catalytic functioning of these enzymes allows lavender or sage species to produce an impressively large array of volatile terpenes. They also provide information on the evolutionary mechanisms at stake behind chemotypic differences among lavender species. Professor Legendre’s extensive research activities include: molecular, cellular and physiological processes of terpene biosynthesis by lavender, sage and camellia; impact of plant domestication on primary and secondary metabolism in tropical tuber crops; and molecular and physiological responses of maize to environmental stresses and to plant growth-promoting associative symbiotic rhizobacteria.