Some plants’ extra chromosome sets may have helped them endure major climate swings
Plants that carry more than the usual two sets of chromosomes can sometimes thrive when conditions become extreme, and new research is offering an explanation for why that genetic trait shows up so often, according to NPR. The report centers on findings published in the journal Cell and on work by plant biologist Yves Van de Peer of Ghent University that connects past bursts of “whole genome duplication” to periods of environmental turmoil.
In the story, Van de Peer frames polyploidy as a large-scale genetic change in which something goes wrong during cell division and results in a “new cell with twice the amount of DNA than a normal plant cell.” NPR describes polyploidy as a phenomenon that can affect a plant’s survival during major stresses tied to the climate, even though duplicating an entire genome can also introduce disadvantages.
That tension is what NPR describes as a “polyploidy paradox”: having extra genetic material is not obviously advantageous in every context, because additional chromosomes can bog down cell division and create more opportunities for errors and mutations. In NPR’s account, the same process that can help a species persist through upheaval can also leave it vulnerable—allowing other plants with “slimmer genetic loads” to outcompete polyploids and potentially contribute to their extinction.
To investigate why polyploidy appears common in modern plants despite those costs, Van de Peer and colleagues examined the history of genome duplications across a broad set of species. NPR says the research team assembled 470 flowering-plant genomes that have been sequenced, including wild species and agricultural crops from around the world, and searched those genomes for repeated genetic patterns that serve as evidence of whole genome duplication events.
NPR reports that the researchers used the fossil record to anchor when different plants first developed, helping them determine when each duplication event occurred. The result, as NPR describes it, was that these whole-genome duplications did not happen randomly in time; instead, the events were “clustered,” pointing to particular stretches of Earth history.
Those clusters, NPR says, align with episodes marked by dramatic environmental shifts—such as important periods of cooling or warming—over the last 150 million years. NPR also describes one prominent clustering event around 66 million years ago, which the report ties to the aftermath of an asteroid collision that likely contributed to widespread extinctions, including the dinosaurs.
NPR describes the researchers’ conclusion as a “superpower” for polyploids: that during the most extreme turmoil, having extra chromosome sets may help plants survive. The report says Van de Peer compares polyploidy to an “insurance policy,” where most of the time polyploid lineages may fade away, but in rare periods of intense stress they can persist and reproduce—leaving behind genetic signatures that remain detectable even after many lineages eventually lose the extra chromosome copies.
The report also describes mechanisms by which polyploidy could matter during stress, including how duplicated genes might help plants better manage fundamental processes when conditions shift, such as using light for photosynthesis. NPR says Van de Peer suggested polyploids might have an advantage in photosynthesis because they may have more genes available to capture limited light during challenging periods, allowing them to persist relative to lineages that lacked whole-genome duplication.
In interviews reported by NPR, the new Cell paper drew support from a scientist not involved in the study. Sandra Pitta, a plant biotechnologist at CONICET in Argentina, described the study as “very rigorous” and said it provides hope, according to NPR, while also pointing to potential implications for breeding plants that can resist stresses under changing environmental conditions.
NPR’s report closes by tying the findings to ongoing climate change pressures on ecosystems, suggesting that understanding how polyploidy behaved during past upheavals could inform efforts to develop or manage plants for future conditions.