Visualising an invisible symbiosis.

Despite the vast abundance and global importance of plant and microbial species, the large majority go unnoticed and unappreciated by humans, contributing to pressing issues including the neglect of study and research of these organisms, the lack of interest and support for their protection and conservation, low microbial and botanical literacy in society, and a growing disconnect between people and nature. The invisibility of many of these organisms is a key factor in their oversight by society, but also points to a solution: sharing the wealth of visual data produced during scientific research with a broader audience. Here, we discuss how the invisible can be visualised for a public audience, and the benefits it can bring. SUMMARY: Whether too small, slow or concealed, the majority of species on Earth go unseen by humans. One such rather unobservable group of organisms are the arbuscular mycorrhizal (AM) fungi, who form beneficial symbioses with plants. AM symbiosis is ubiquitous and vitally important globally in ecosystem functioning, but partly as a consequence of its invisibility, it receives disproportionally little attention and appreciation. Yet AM fungi, and other unseen organisms, need not remain overlooked: from decades of scientific research there exists a goldmine of visual data, which if shared effectively we believe can alleviate the issues of low awareness. Here, we use examples from our experience of public engagement with AM symbiosis as well as evidence from the literature to outline the diverse ways in which invisible organisms can be visualised for a broad audience. We highlight outcomes and knock-on consequences of this visualisation, ranging from improved human mental health to environmental protection, making the case for researchers to share their images more widely for the benefit of plants (and fungi and other overlooked organisms), people and planet.