Growing potatoes on the Moon is still the stuff of science fiction, due to scarce nutrients and weak gravity, but plant biologists from the University of Zurich have suggested the plant hormone strigolactone could help make it work. According to researchers, the hormone supports the symbiosis between fungi and plant roots, encouraging plants’ growth, even under the challenging conditions found in space. The likes of Nasa and private entrepreneurs such as Jeff Bezos and Elon Musk have been trying to find ways to make this concept viable, in the event of one day establishing colonies for people to live on the Moon or other planets in the future. However, such visions, as well as the prospect of long-term human space expeditions in the future, raise the question of how to provide sustainable food sources for the people in space. 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, and the process of mycorrhization can increase plant growth and thereby improve crop yields, especially in soil that is low in nutrients. In space, cultivated plants would not only have to contend with low-nutrient soil, but also with conditions of microgravity. So, to investigate the influence of such an environment on plant growth, the researchers cultivated petunias – a model organism for plants of the nightshade family (solanaceae), which include tomatoes, potatoes and aubergines, for example – and mycorrhizal fungi under simulated low-gravity conditions. Research leader Borghi said: “In order to get crops such as tomatoes and potatoes to grow in the challenging conditions of space, it is necessary to encourage the formation of mycorrhiza. This seems to be possible using the strigolactone hormone. Our findings may therefore pave the way for the successful cultivation in space of the types of plants that we grow on Earth.” Experiments showed that microgravity hindered the mycorrhization, reducing the petunias’ uptake of nutrients of the soil, but strigolactone can counteract this negative effect. The researchers had treated plants that contained high levels of strigolactone and fungi with a synthetic strigolactone hormone, resulting in these plants successfully growing in the low-nutrient soil despite microgravity conditions. In August, US scientists from the University of Vermont suggested that burgeoning insect populations brought about by global warming could be a major factor in future crop losses. The same month saw Japanese farmers using drones to fertilise their crops and spray pesticides as a shortage of labour plagues the rural areas of the country. In February, researchers at the John Innes Centre in Norfolk, a leading British plant science centre, said gene-edited agricultural crops could be produced to overcome the increasing problem of ‘pod shatter’, which is being exacerbated by global warming.
Researchers at the University of Zurich believe the plant hormone synthesis could help make farming possible in space . The plant biologists found the hormone supports the symbiosis between fungi and plant roots , helping growth even amid difficult conditions found outside of Earth ’s atmosphere . They tested petunias – a model organism for plants that produce potatoes and tomatoes – with the symbiotic mycorrhizal fungi , in simulated space - like low - gravity environments . Results showed the latter part of the process was slowed by microgravity , but strigolactone countered the effect and helped plants still grow in the low - nutrient environment .