While studying California dryland biocrusts (communities of living organisms which inhabit the surface of soils), researchers from University of California Riverside found something unlikely inside moss.<\/p>\n
Not only could the discovery completely rewrite what we know about moss biology, but it could also offer an insight into how plants first moved from the oceans<\/a> onto land around 470 million years ago.\u00a0<\/p>\n For a long time, scientists have taken one fact for granted: fungi<\/a> and moss don\u2019t establish symbiotic relationships with each other (moss would be the only major lineage of land plants with that trait).<\/p>\n A new\u00a0study<\/a>\u00a0published in the journal\u00a0New Phytologist\u00a0argues this might be a premature assumption. Given the millions of years of evolutionary history of both mosses and fungi, it\u2019s quite unlikely they wouldn\u2019t evolve any symbiosis.\u00a0<\/p>\n To investigate this, researchers collected samples of the same species<\/a> of moss from the scorching<\/a> landscapes in the Mojave and Sonoran deserts, as well as less arid climates, to compare them. They wanted to find out whether differences in climate might coincide with differences in fungal communities inside moss.<\/p>\n To figure that out, they ground up moss samples, searched for fungi DNA within them \u2013 and struck gold. They were particularly surprised to encounter mycorrhizal fungi, which cannot survive without a plant host.\u00a0<\/p>\n The fungi inside moss collected from the desert wasn\u2019t the same as the fungi inside moss grown in more forgiving conditions. And perhaps more interestingly, the species of fungi inside the dryland mosses didn\u2019t match the ones found in the dirt near them \u2013 suggesting the connection wasn\u2019t random contamination, but perhaps a more deliberate relationship.\u00a0<\/p>\n \u201cWe suspect that certain fungi are more helpful for surviving hotter, drier climates,\u201d said Kian Kelly, a doctoral researcher University of California Riverside.<\/p>\n Fungi DNA in moss isn\u2019t enough to establish a symbiotic relationship, so the researchers dug deeper by turning to microscopy. They stained moss tissue with a blue dye that sticks specifically to fungi and found branching fungal structures resembling tiny tree-shaped formations fungi normally build within plant roots to swap nutrients.\u00a0<\/p>\n They weren\u2019t the same, though \u2013 mosses don\u2019t have roots, so the structures actually appeared in leaves instead. Further studies are needed to establish whether the two organisms are swapping nutrients before the relationship can officially be declared a true symbiosis.<\/p>\n Importance of moss<\/p>\n Drylands (zones defined by the scarcity of water) encompass around 45 per cent of Earth\u2019s land surface, and biocrusts cover up to 70 per cent of those drylands, acting out a crucial role in the race against climate change<\/a>.\u00a0<\/p>\n Mosses alone absorb 6.4 billion tons of carbon annually \u2013 but moss biocrusts are some of the most susceptible to climate change. Biocrusts in general are predicted to experience up to 39 per cent land area loss in the next 45 years.\u00a0<\/p>\n It\u2019s crucial we understand as much as we can about the biological intricacies of moss to help predict the effects of rising aridity in the drylands \u2013 and hopefully mitigate them.\u00a0If the symbiotic partnership between moss and fungi is confirmed, it could also help scientists better understand the origins of life on Earth.\u00a0<\/p>\n \u201cThe desert is full of things people overlook. Sometimes, the biggest surprises are the ones growing quietly beneath our feet,\u201d said Kelly.\u00a0<\/p>\n