A new study has mapped pathogen hotspots worldwide and revealed how soils naturally suppressed disease, highlighting climate-driven risks.

Led by Professor Brajesh Singh, from UWA School of Agriculture and Environment and The UWA Institute of Agriculture, and published in Nature Communications, the study developed new tools that detected pathogens, beneficial microbes and functional genes.

The research has created a foundation for improved surveillance tools and microbiome-based strategies to reduce plant disease risks under a changing climate.

Scientist used predictive models to show that climate change may further increase pathogen risks, with several dominant bacterial plant pathogens likely to expand their ranges under future climate scenarios.

“We identified 32 dominant pathogens by studying 1602 soil metagenomes from 59 countries,” Professor Singh said. 

“Our study found global hotspots of plant pathogen occur in warm ecosystems and agricultural soils, whereas high microbial diversity, increased soil organic carbon, and colder climatic conditions are associated with lower pathogen prevalence.” 

Plant diseases caused by bacterial and fungal pathogens reduced global agricultural productivity by hundreds of billions of dollars annually and threatened food security. 

In natural ecosystems, diseases lowered primary productivity, diminished biodiversity and reduced ecosystem carbon storage.

“Farmers are facing increasing disease pressures because of the minimal availability of effective chemical and resistant crop varieties,” Professor Singh said.

Professor Singh’s group had previously reported global maps of dominant fungal and oomycete pathogens in soil but detecting bacterial pathogens has been technically and bioinformatically demanding. 

“Identifying the global distribution of dominant pathogens and the environmental and management practices that enhance or suppress pathogen abundance is critical for reducing the impacts of plant disease on global food production,” Professor Singh said.