Corn Genome Unveils Multi-Disease Resistance Pathways

A groundbreaking study led by researchers at the University of Illinois Urbana-Champaign has uncovered a significant breakthrough in corn breeding, revealing genomic regions within the corn genome that confer resistance to multiple devastating diseases simultaneously. Published in G3: Genes, Genomes, Genetics, the study marks a pivotal step towards developing corn varieties with enhanced resilience to a range of foliar diseases, offering a promising solution for growers grappling with evolving disease dynamics in a changing climate.

Foliar diseases pose a significant threat to maize crops globally, with bacterial afflictions like Goss’s wilt, alongside fungal infections such as gray leaf spot, northern corn leaf blight, and southern corn leaf blight, wreaking havoc on yields. The research focused on identifying genetic markers associated with resistance to all four diseases, laying the groundwork for future breeding efforts aimed at developing multi-resistant corn varieties.

Led by senior author Tiffany Jamann, the study utilized strategic crosses between disease-resistant and susceptible corn lines to pinpoint genomic regions linked to disease resistance traits. While the exact genes responsible for resistance remain unidentified, the identification of key genomic regions provides a critical foundation for further exploration.

Notably, the study revealed that resistance to bacterial and fungal pathogens may share common genetic pathways, suggesting a potential convergence in the mechanisms underlying plant defense. This finding opens new avenues for breeding strategies targeting multiple diseases simultaneously, harnessing the additive power of multiple genes to confer durable resistance.

“Resistance to multiple diseases at once is a game-changer for corn growers, offering enhanced protection against evolving disease pressures,” remarked Jamann. “Our research not only identified promising corn lines resistant to all four diseases but also uncovered shared genetic regions associated with resistance, paving the way for future breeding efforts.”

While the development of commercially available multi-resistant corn varieties may be on the horizon, further research is underway to fine-map the identified genomic regions and elucidate the underlying mechanisms of resistance. Armed with this knowledge, breeders can tailor breeding programs to incorporate high-impact genes into new hybrids, offering growers robust solutions to combat foliar diseases.

As Jamann emphasizes, “Multiple disease resistance is within reach, thanks to advancements in genomic research and collaborative efforts between academia and industry. With continued innovation, we can empower growers with resilient corn varieties capable of withstanding the complex challenges posed by foliar diseases.”

More information: Yuting Qiu et al, Identification of loci conferring resistance to 4 foliar diseases of maize, G3: Genes, Genomes, Genetics (2023). DOI: 10.1093/g3journal/jkad275