Project

Discipline

phytochemistry; Chemical ecology; Phylogenetic analysis; chemical analytical tools; Plant-insect interaction; elevation gradients

Lead
Les métabolites chimiques produits par les plantes gouvernent toutes les interactions entre les plantes et leur environnement. Les origines et les causes de cette diversité phytochimiques sont encore très peu étudiées. Le projet apporte sa contribution à ce domaine de recherche.
Lay summary
Tout au long de savie, chaque plante produits des milliers de molécules chimiques qui servent spécialementpour mieux tolérer les conditions du milieu, pour mieux se protéger contre lesravageurs et pathogènes, et de manière générale, pour communiquer avec d’autresorganismes.   Les butsprincipaux de ce projet sont de mieux comprendre comment les conditionsenvironnementales et biotiques (animaux, microorganismes) du milieu influencentla production de ces composés chimiques (aussi appelés métabolites secondaires).Ensuite, nous avons comme but de comprendre comment la composition chimique dela plante peut influencer la décomposition de la matière organique végétale, eten générale de mieux comprendre les cycles bio-géo-chimiques de la matièreorganique. Pour faire celanous travaillerons sur les pentes montagneuses des Alpes Suisses. Un gradient écologiquenaturel optimal pour tester nos hypothèses.   Les résultats dece projet pourront informer de manière plus vaste la recherche en agroécologiepour mieux sélectionner de variétés végétales adaptées à leur milieu. Deuxièmement,notre développent d’analyses chimiques spécifiques pourra aussi être appliqué àla recherche de nouveaux produits médicaux produits par les plantes.

Direct link to Lay Summary

Last update: 18.04.2018

Natural persons

Number	Title	Start	Funding scheme

Phytochemical diversity, or the amount of individual chemical compound species within plants, governs the overwhelming complexity of interactions between plants and their biotic and abiotic environment. While several thousand phytochemicals have already been identified, for only a small fraction of them has the ecological function been elucidated. In addition, while functionalities for most phytochemicals could be predicted from chemical structure analysis, the ecological role of the majority of phytochemicals seems to be redundant or has no direct functionality. This project therefore aims at tackling the overarching question of the ecological causes and consequences of variation in phytochemical diversity within and between plant taxa. I propose to answer this question using the natural variation in biotic and climatic variables that exists when moving from low to high elevations, such as along Alpine mountain transects. Elevation gradients offer perfect tools for measuring variation in putative causes - and consequences - of phytochemical diversity, including biotic pressure, edaphic factors, and climatic conditions. I will sample vegetation, and phytochemical composition therein, along several mountain transects of the Alps spanning several biomes and climatic conditions. I will next perform manipulative experiments in common gardens at different elevations to dissect the effect of individual factors on plant phytochemical production. In turn, common garden experiments in the Alps that manipulate phytochemical composition will identify the effects of phytochemical diversity on the surrounding animal and microbial communities. One of the keys to the success of such a project is the combination of different approaches. Plant chemistry will be analysed through high-throughput chromatography, mass spectrometry and various other chemical analytical techniques. I will then include field experiments where plants and herbivores will be factorially manipulated to specifically quantify the relative contribution of biotic (herbivory) and abiotic (e.g., soil nutrients, temperature) factors to phytochemistry. Also, I will use genomic information to create phylogenetic trees of the studied species, in order to address questions on the macroevolution of phytochemistry along elevation gradients. All of these results will enhance our knowledge of the ecological and evolutionary processes that drive phytochemical diversity, and how this drives community assembly and the maintenance of biodiversity.