Fire Fungi Can Steal Genes Across Kingdoms. What That Means for Rebuilding Burned Forests.

Researchers at the University of California, Riverside have sequenced the genomes of 18 species of pyrophilous fungi, the fire-loving organisms that colonize burned land within weeks of a wildfire, and published the results in the Proceedings of the National Academy of Sciences in January 2026. The team, led by microbial ecologist Sydney Glassman, collected specimens from seven burn sites across California and cultivated them in the lab over five years. Their goal was straightforward: find out why these organisms flourish where almost everything else dies.

What they found goes considerably deeper than fire tolerance. Among the mechanisms Glassman's team identified is cross-kingdom horizontal gene transfer: these fungi carry genetic code originally belonging to bacteria, absorbed at some point in their evolutionary past. It's the same class of molecular transaction that drives antibiotic resistance. Finding it in fungi, specifically wired to charcoal digestion and post-fire soil recovery, pulls the finding out of bacterial biology and into a broader question about how complex organisms acquire new capabilities fast.

The Antibiotic Resistance Connection Nobody Made

Coverage of this study framed it mainly as an ecology story: colorful cup-shaped fungi appearing on charred ground, a reminder that nature bounces back. That angle isn't wrong. It buries the more consequential thread.

The genetic mechanism at the center of Glassman's research is structurally identical to the one making bacterial infections harder to treat every year. Horizontal gene transfer in bacteria works like this: rather than waiting for a useful mutation to arise and propagate through generations, bacteria can pass functional genes directly to other individuals, even across species. A resistance gene can jump from one bacterial species to another in a single transfer event. That's why resistance can appear in a hospital population within days of antibiotic exposure, not across evolutionary timescales.

Glassman's team found evidence that the ancestors of certain fire fungi absorbed bacterial genes through the same process. Those genes encode enzymes that break down pyrogenic carbon: the charcoal, soot, and ash that dominate post-fire soil.

The fungi didn't develop this capability gradually. They borrowed it.

That matters for applied biology because horizontal gene transfer has historically been studied almost exclusively in pathogen contexts. Finding it documented as a stable adaptation mechanism in a non-pathogenic organism, in a well-characterized ecological setting, adds a reference case researchers can learn from. The more examples of cross-kingdom gene transfer science can examine in detail, the clearer the rules governing when and how it occurs. Clearer rules mean better tools for predicting when dangerous genes might cross biological boundaries you didn't expect them to cross.

Erin Spear, a mycologist at the Smithsonian Tropical Research Institute, notes that these fungi "play this really important functional role in releasing nutrients that plants can use, improving the structure, or recreating the original soil structure, and allowing water to filter through the soil." The genetic work explains, for the first time, how they got that role.

The Glassman Lab and the Biotech Applications Worth Watching

For readers tracking where applied genetics is heading, Glassman's lab at UC Riverside is the group to follow after this paper. The five-year cultivation component produced a viable library of pyrophilous fungal strains. That library is the foundational material for any downstream application in bioremediation, carbon cycling research, or targeted post-fire restoration.

The practical signal here: the science has moved from observation to mechanism. Knowing that fire fungi colonize burn sites has been documented in the mycological literature since at least 1909. That those specific fungi carry bacterial genes acquired through cross-kingdom transfer, rather than evolved in place, changes the design space for engineered applications entirely. You can't engineer what you can't precisely describe.

California's wildfire burn area has repeatedly exceeded 1 million acres in recent years. The pressure on land managers and restoration ecologists to find scalable soil recovery tools is not theoretical. Genomic profiling of pyrophilous fungi doesn't produce a restoration product on its own, but it defines the molecular targets precisely enough to make building one realistic. That's the stage this science just reached.

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