The idea has been bounced around for a while now -- and not just by the likes of NASA, but also by private entrepreneurs such as Jeff Bezos and Elon Musk: that of one day establishing colonies for people to live on the Moon or on other planets. Such visions, as well as the prospect of long-term human space expeditions in the future, raise the question of how to sustainably provide food for the people in space. One possible answer is to cultivate crops in situ. However, the soils on the Moon and on other planets are surely lower in nutrients compared to our agricultural land. The alternative -- transporting nutrient-rich soil and fertilizers up into space -- comes with a high economic and ecological cost.

Plant-fungal symbiosis promotes plant growth

When looking for a possible solution, the research group working with Lorenzo Borghi of the University of Zurich and Marcel Egli of the Lucerne University of Applied Sciences and Arts concentrated on the process of mycorrhiza, a symbiotic association between fungi and plant roots. In this symbiosis, the fungal hyphae supply the plant roots with additional water, nitrogen, phosphates and trace elements from the ground. In return they get access to sugar and fat produced by the plant. This symbiosis is stimulated by hormones of the strigolactone family, which most plants secrete into the soil around their roots. The process of mycorrhization can greatly increase plant growth and thereby substantially improve crop yields -- especially in soil that is low in nutrients.  Full Article: