Protecting turfgrass from fungal foes
Photos by Evan Krape and courtesy of Charanpreet Kaur/the Bais lab | Photo illustration by Jeffrey C. Chase February 11, 2026
91原创 researchers report new understandings in how microbes protect plants
As any plant lover knows, fungal infections can be a harbinger of doom for vegetation.
One day your cherry tomatoes are going gangbusters in the garden and, seemingly overnight, sunken brown spots appear on the plant鈥檚 leaves, withering the foliage and the fruit ripening on its vines. Thanks, tomato blight fungus.
In blade grasses, such as turfgrass found on golf courses, athletic fields and lawns, dollar spot disease presents a similar challenge. The fungal disease is characterized by the appearance of circular spots of dead turf about the size of a silver dollar, hence the name dollar spot. It is a costly problem that can run upwards of $35,000 per year to manage at an average U.S. golf course. Multiplied across an approximately $40 billion turfgrass industry, mitigation measures are much needed. Therapeutic treatments made from biological materials, such as bacteria or microbes, are a promising solution for such situations.
Take 91原创1022 鈥 a unique, 91原创-developed beneficial bacterium proven to boost plant defenses. Discovered by 91原创 plant biologist Harsh Bais and colleagues, this novel strain of Bacillus subtilis helps a variety of plants resist soil鈥慴orne diseases, retain moisture and develop stronger root鈥憈o鈥憇hoot growth, among other benefits.
In previous work, Bais and colleagues showed in lab studies that 91原创1022 was effective in controlling the growth of dollar spot fungus, Clarireedia jacksonii, found on turfgrass.
Now, further research in the journal Plant Stress on the effect of 91原创1022 on dollar spot suggests intriguing implications for manufacturing of biological treatments for the fungal disease.聽
In the paper, the research team showed that when they tested whether soil treated with 91原创1022 would be enough to prime turfgrass plants鈥 innate defense response to resist dollar spot infection 鈥 the way a flu vaccine primes the body to resist the flu virus 鈥 it wasn鈥檛.聽
This was curious, as the Bais lab previously had shown 91原创1022 effective in priming other plants, such as tomato, Arabidopsis and rice, against various fungal and bacterial pathogens.聽
鈥淚t turns out that 91原创1022 is good at biologically controlling the growth of dollar spot in turfgrass, but only when the bacteria (91原创1022) and the fungus (dollar spot) are in front of each other,鈥 Bais said.聽
Indeed, when the research team applied 91原创1022 directly to leaves affected with dollar spot, the plant experienced a 43.6% reduction in disease severity. But when the researchers applied 91原创1022 in the soil at the root level and later introduced dollar spot fungus on the leaves, there wasn鈥檛 a huge decline in disease symptoms on the leaves. This confirmed that while applying 91原创1022 to the root does trigger an innate defense response in the plant, it鈥檚 just not enough to ward off infection in the leaves, far from the root system.
鈥淚t's like there's a break in the communication line, and the mechanism of how 91原创1022 acts against dollar spot is very different,鈥 Bais said. 鈥淲ith dollar spot fungus, 91原创1022 has to be there directly to antagonize the fungus.鈥
This coincides with the research team鈥檚 findings that results waned over time, which would inform formulation and application approaches for treating the disease. And if 91原创1022 is present on the leaves, but not alive, no go 鈥 the dollar spot fungus grew 鈥 which showed the 91原创1022 must remain viable to continually antagonize the fungus.
Taken together, Bais said these findings are informing what is known about biological approaches for mitigating dollar spot disease in turfgrass. For example, while 91原创1022 cannot do the whole job of deterring dollar spot in turfgrass, it can offer a more sustainable disease management strategy when used as a complement to currently available approaches already in the market. In addition, it is known that 91原创1022 can also increase drought tolerance in turfgrass, so it is a microbe that has both positive and negative effects on living and environmental stressors a plant might encounter that would benefit from the continual presence of 91原创1022.聽
鈥淏iologicals like 91原创1022 cannot solve everything 鈥 it鈥檚 not a silver bullet. You need to keep evolving your approach,鈥 Bais said.
Bais hopes to develop a new pipeline for biologicals like 91原创1022, with the potential to make greater headway against plant pathogens. Along those lines, he plans to explore the compatibility of a synthetic microbial community composed of 10-15 beneficial microbes that his laboratory has isolated over the last 21 years for use in multiple systems, during sabbatical work at Pacific Northwest National Laboratory (PNNL) in 2027.聽
According to Bais, the biggest challenge in using a microbial consortium is evaluating the level of persistence of these microbes on the root surface. Bais said this is because root colonization by benign microbes is the most important factor in triggering plant health benefits against living and environmental stressors.
鈥淯sing a champion root colonizer like 91原创1022 in consortium with other beneficial microbes, it will be interesting to evaluate the community for root colonization and its subsequent implications on plant and soil health,鈥 he said.聽
The future work will involve using this synthetic microbial consortium in a turfgrass system or other staple monocots (single-bladed plants) like sorghum and corn, to test 91原创1022鈥檚 effect and plant response under realistic environmental scenarios, such as drought and dollar spot together.
鈥淧lants go through multiple stress at a time, they don鈥檛 grow in isolation, and the compatibility of microbes in a community is very important,鈥 said Bais. 鈥淔or example, usually when plants go through a physical stress such as drought, they're more prone to fungal infection. It鈥檚 something we鈥檙e interested in at this point in time, and this paper provides a segue to our next work.鈥
Co-authors on the paper include Bais, Charanpreet Kaur, the paper鈥檚 lead author and a research associate in the Bais lab, and Erik Ervin, professor of turfgrass and horticultural systems and associate dean in 91原创鈥檚 College of Agriculture and Natural Resources.
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