The Press-Dispatch
Issue link: https://www.ifoldsflip.com/i/1408154
Invisible, devastating and sustaining: Research explores mysterious microfungi By Elizabeth K. Gardner, Purdue News Service The world around you is teeming with life you can't see. Plants, soil, water, insects – even your hair and skin – are home to microfungi, and they both sustain and devastate life on our planet. Parasitic microfungi, which live off host plants and ani- mals, maintain balance in nat- ural ecosystems. But in devel- oped areas, they can quickly destroy crops and financially devastate communities. A team led by Purdue Uni- versity mycologist Catherine Aime will venture to the trop- ics – where the vast majority of emerging crop diseases orig- inate – and sites across the globe to discover and identify thousands of kinds of parasit- ic microfungi. "To effectively combat any disease, you need to identi- fy it and understand how it works," said Aime, a profes- sor in the Department of Bot- any and Plant Pathology. "Par- asitic microfungi are the ma- jor cause of crop disease in the world. Through this work we hope to stay one step ahead, so that when the next disease strikes, we won't be starting from scratch." The team will focus on two parasitic microfungi groups: Pucciniales, which causes rust disease in plants, and Laboulbeniales, which par- asitizes insects. The project is supported by $1.5 million from the National Science Foundation, and also seeks to help resolve the "Tree of Life" for these groups. "Microfungi are among the least understood living organ- isms on the planet, and they can be rule breakers," Aime said. "Rusts don't follow the typical patterns of evolution. Where we expect to see the genomes of parasites become compacted over time, theirs have expanded and we don't know why. This study could lead to a fundamental change in the way we understand ge- nome architecture. The impli- cations could extend even to organisms beyond fungi." Aime is a pioneer in the identification of parasitic mi- crofungi that cannot be put in- to culture. Her team will ar- range community bat nights, in order to capture bat flies, and roach hunts to round up samples of the Laboulbeniales microfungi. She also will use DNA-se- quencing techniques to per- form identification that previ- ously was impossible. "Many microfungi viewed under a microscope are indis- tinguishable," she said. "For instance, Pucciniales has five different spore stages, each of which looks different within a species. But the same spore stages can look the same be- tween species. This makes identification, or even under- standing a single life cycle, difficult. "DNA sequencing," Aime added, "allows us to clearly see distinctions and properly identify separate species and stages of development. We chose two of the least stud- ied – but very consequential – types of microfungi, and we will be providing the first ge- nomic resources for most of the species within them." The research will evaluate what geographic regions have the highest diversity of para- sitic microfungi and will test the latitudinal gradient hy- pothesis established for plants and animals. "This hypothesis suggests diversity is negatively linked to increasing latitude," Aime said. "However, some recent studies suggest the opposite to be true for fungi. We think this may be due to the patchi- ness of fungal distribution in the tropics, like a quilt where one square doesn't tell the sto- ry of the full, colorful piece. Our standardized sampling in tropical and temperate ar- eas will, for the first time, al- low for a robust comparison." The team will collect mi- crofungi in North Carolina domestically as well as Pata- gonia, Czech Republic, Cau- casus, Panama, Guyana, Mo- zambique and Brunei. Aime is one of the only ac- ademic mycologists in the na- tion who specializes in Puc- ciniales, and she said part of this project seeks to build the capacity for mycological stud- ies in the U.S. and other coun- tries. "There are more than six times as many species of fun- gi as plants, but there aren't very many mycologists at uni- versities," she said. "It is a new field, relatively speaking, be- cause until the 1970s fungi were classified under the plant kingdom. Now we know fun- gi is a kingdom itself, and the organisms actually have more in common with animals than plants. There is so much to learn, and we need to scale up mycological education and professional training." The project will include undergraduate and gradu- ate level education, commu- nity engagement, and the or- ganization of workshops and fieldwork programs. Anoth- er important aspect will be the creation of a platform to house and share a rapidly growing microfungi dataset, Aime said. "We expect to create the most exhaustive documenta- tion of microfungi in these two orders to date," she said. "This massive dataset will be a rich and growing resource that can inform fungal systemat- ics, ecological and evolution- ary research." The flipside of disease pre- vention is the need to under- stand parasitic microfungi to sustain ecosystems. "In nature, these para- sites are critical to ecosystem health," Aime said. "They play an important role by encour- aging diversity in their hosts. They prevent one species from taking over and maintain bal- ance. If we want to preserve or restore habitats, we have to look at the whole system, including what we can't see. These microbes are as import- ant as the plants and animals." Aime is collaborating with Carl Dick, an associate pro- fessor of biology at Western Kentucky University; Danny Haelewaters, a postdoctoral fellow at Ghent University; Al- isha Quandt, assistant profes- sor of ecology and evolution- ary biology at the University of Colorado Boulder; and Ky- ryll Savchenko, assistant pro- fessor of biological sciences at Butler University. Other collaborators include Meredith Blackwell professor emeritus of biology at Louisi- ana State University; Don Pfis- ter, professor emeritus of or- ganismic and evolutionary bi- ology at Harvard University; and Giuliana Furci, CEO of the Fungi Foundation in Chile. Pucciniales, a type of parasitic microfungi that causes rust disease, is shown on a leaf. Purdue professor Catherine Aime is one of the only mycologists in the nation who specializes in Pucciniales. With support from the National Science Foundation, she and her team will work to identify thousands of kinds of parasitic micro- fungi across the globe. Image provided by Catherine Aime C-8 Wednesday, September 8, 2021 The Press-Dispatch