Evaluation in vitro de l’interaction entre les microalgues C. vulgaris et S. dimorphus et la symbiose mycorhizienne de champignons mycorhiziens à arbuscules du genre Rhizophagus

Details

Supervisors

Stephan Declerk

Faculty

Faculté des bioingénieurs

Degree label

Master [120] : bioingénieur en sciences et technologies de l'environnement

Abstract

In the context of research for sustainable development the limitation of chemical inputs in agriculture and more extensive ways of producing food are in demand. Similarly, the production of biofuels and materials from renewable resources is highly required. Therefore, the demand of biomass of all kinds and in particular from microalgae is growing. These sub-products, the microalgae supernatants containing many compounds with diversified functions are looking for new valorization fields. The effects of these bio-sourced compounds on plants and mycorrhizal associations are relatively unexplored. However, some previous studies have open perspectives for their potential uses for stimulatory effects on the arbuscular mycorrhizal fungi. These obligate root symbionts improve hydric and mineral nutrition of plants and increase their resistance to abiotic and biotic stresses. A stimulation of the mycorrhizal association by microalgae exudates could help the fungi in reducing the use of agrochemical in agriculture production. The focus of this work is set on the interaction between microalgae and AM fungi. In two first experiments, in line with a more applied approach, we aim to characterize the effects of molecules/components issued from microalgae on the germination of AM fungal spores and their hyphal growth. They revealed promising results in regard to the applied objective of the use of microalgae exudates and spores as substitute to agricultural biochemicals. Taken together, the findings suggest the microalgae exudates have stimulating effects on hyphal elongation and branching at a certain concentration up to a threshold concentration, where no effects are observed. A third experiment tries to answer a more fundamental question; Does the AM fungus provide sugars to the microalga in a dark environment with no source of sugar? Although this hypothesis was not verified within the framework imposed by this work, interesting observations were made regarding the interaction between C. vulgaris and S. dimorphus and the AM fungus-plant symbiosis that opens up perspectives for further research.