Research
Like the gut microbiome of humans, plants associate with millions of microbes that live on or inside plant tissues such as leaves and roots. Most land plants, including important crops such as rice, maize, and wheat, are able to establish a beneficial symbiosis with soil-borne arbuscular mycorrhizal (AM) fungi. This association is one of the oldest and most widespread symbioses on Earth and provides key benefits to plants: AM fungi act as a highly efficient, far-reaching extension of the root system and deliver up to 90% of the nutritional demand of their plant hosts. Through enhanced mineral nutrition, the association with AM fungi can increase crop yields by up to 30%. Thus, AM symbiosis could play a vital role in sustainable agriculture by reducing the need for economically costly and environmentally damaging fertilizer.
In return for mineral nutrients, plants supply AM fungi with substantial quantities of fixed carbon, the product of photosynthesis. Carbon tracing experiments suggest that 10-30% of assimilated carbon in plants is allocated to AM fungi in the soil. The extent of carbon transfer from plants to AM fungi has a significant impact on the global carbon cycle. It has been estimated that every year one gigaton of carbon is drawn down from the atmosphere by plants and transferred to the AM mycelial network in the soil. This corresponds to more than 10% of global carbon emissions caused by fossil fuels.
However, the molecular mechanisms underlying carbon transfer from plants to AM fungi are poorly understood. By combining carbon tracing and (single-cell) transcriptomics approaches with targeted mutagenesis, microscopy imaging, and molecular biology techniques in the model species rice and Medicago truncatula, we aim to address the following questions:
What are the key molecular players that drive carbon flux from shoots to roots and to AM fungi?
We aim to map the molecular pathway that drives carbon allocation to AM fungi at a whole plant level and at single cell resolution.
How do plants regulate carbon allocation to AM fungi?
We aim to identify the key points of control as well as genetic and transcriptional regulators of the carbon allocation pathway from plants to AM fungi.
Can we engineer plants with increased carbon delivery to the fungal mycelium in the soil?
We aim to engineer crops such that carbon transfer to AM fungi is enhanced by altering key steps of carbon assimilation and delivery from shoots to roots and to AM fungi.