New Research Shines Light On Historical Outbreaks Of Coffee Wilt Disease – CoffeeTalk

A study published in PLOS Biology by Lily Peck of Imperial College London has found that the fungus responsible for coffee wilt disease, Fusarium xylarioides, has repeatedly taken up DNA from a related pathogen, contributing to successive outbreaks of the disease. The study compared the genomes of 13 historical strains spanning six decades and multiple disease outbreaks to investigate how the pathogen has evolved and adapted to its host plants. The researchers found that F. xylarioides is made up of at least four distinct lineages: one specialized to live on arabica coffee plants, one adapted to robusta coffee plants, and two historical lineages that infected multiple coffee species. The researchers also found evidence that these strains had repeatedly received segments of DNA from another fungal pathogen, F. oxysporum, which enhanced F. xylarioides’s ability to infect coffee plants. These additions of DNA, called horizontal gene transfer, likely contributed to the repeated emergence of coffee wilt disease on the African continent. Previous studies have shown that similar horizontal gene transfer events contributed to new outbreaks of other pathogens, including potato blight, certain wheat fungal pathogens, and Aspergillus fumigatus, a fungus that most commonly infects immunocompromised individuals. The researchers concluded that using genomics techniques on historical strains of fungi, sampled during the last century and held in culture collections, would provide a powerful way to further investigate the role of horizontal gene transfer in fungal outbreaks.

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