Action underground: symbiosis evolution in real time
In this project you will engage in cutting-edge research on the dynamic evolution of symbiosis between plants and underground-dwellers. This research will be the final phase of a Multi-generational greenhouse experiment involving international collaboration.
Only those that are interested in publishing their results should apply.
Methods to be applied:
Establishing plant cultures
Simulation of various selection regimes
Novel molecular techniques: detecting species abundance in-situ
Assessing microscopic features of the organisms
Detailed description:
Arbuscular mycorrhizal fungi (AMF) engage in a symbiosis with about 80% of all land plant species, thereby providing the plant with nutrients from soil in exchange for photosynthesis-derived carbon.
Apart from nutrient supply, there is a whole range of benefits AMF can supply such as: protection against pathogens, water supply and improving soil structure. Not all AMF are as good as others at providing benefits, which increases its own fitness when the AMF can keep the nutrients it would supply to the host for itself. This creates a strong incentive for the plant to only supply “mutualist” AMF with carbon, and therefore the plant has to distinguish between “good” and “bad” AMF.
As plants are often colonized by different strains of AMF simultaneously this distinction can be very hard, with the risk of supplying carbon to “selfish” AMF. We hypothesize that plants need spatial structure of the fungi colonizing the roots, in that the distinction is much easier when there are good and bad patches of fungi.
When patches of fungi are larger it is easier to distinguish good and bad, but when they become smaller it becomes harder and harder and this will benefit the bad AMF.
In a greenhouse experiment we will have a treatment with plants growing with a strongly mixed soil of good and bad AMF (right), a treatment with a moderate spatial structure that has been created by a plant growing on a mixed soil and thereby having already created patches of selected AMF (middle), and a treatment with a pot where there is a divider in the middle separating good and bad strains, thus having very strong spatial structure (left).
Please send an e-mail so we can meet! As we anticipate several applicants, we will choose the one with best motivation.
Info: erik.verbruggen@falw.vu.nl , Toby.kiers@falw.vu.nl
More reading on mutualism evolution:
