polyploid plants – A large global analysis of flowering plant genomes suggests whole-genome duplications—called polyploidy—often arise during major upheavals on Earth, including times marked by cooling, warming, and even the asteroid impact 66 million years ago. The findings, pu
Most of the world has two sets of chromosomes—one inherited from each parent. For some plants, though, the rule is different. Strawberries, for example, can carry eight sets of chromosomes.
That unusual genetic architecture is part of a phenomenon plant biologists call polyploidy: organisms end up with more than two sets of chromosomes in every cell. effectively duplicating an entire genome. It’s common in plants, and it has also posed a stubborn mystery. Polyploidy happens when a mutational event creates cells with twice the normal amount of DNA. But that wholesale duplication is error-prone, and often comes with a price.
Yves Van de Peer. a plant biologist at Ghent University in Belgium. points to a pattern that can undermine survival: reduced fertility. With extra chromosomes to manage, cell division becomes more complicated, and that can threaten the ability to persist. Over time. polyploid plants often seem destined for extinction—yet polyploidy is also everywhere. which is why the contradiction has kept researchers puzzling for years.
To untangle that paradox, Van de Peer and colleagues took an ambitious step. They gathered 470 flowering plant genomes that have been sequenced, spanning wild species and agricultural crops from across the world. The team then scanned the DNA for evidence of genome duplication events that occurred long ago.
Not every plant showed signs of these duplications. But for the ones that did, the researchers used the fossil record to estimate when each event happened. What emerged wasn’t a random spread across time. According to Van de Peer, the whole-genome duplications cluster in specific eras.
Those eras line up with periods marked by environmental upheaval over the last 150 million years. The timeline includes important cooling periods and global warming events on Earth. And it includes one of the most dramatic turning points in the history of life: 66 million years ago. when an asteroid collided with Earth. darkening the skies and likely wiping out the dinosaurs and over half of all plant species.
In those moments, the pressure on living things is sudden and severe. Van de Peer describes the consequence simply: plants were suddenly no longer adapted.
The study suggests that, despite the early drawbacks—like reduced fertility—polyploid plants may have an edge during extreme stress. Van de Peer says polyploid plants excel at surviving environmental stress such as prolonged changes in temperature or light levels. One proposed advantage is in photosynthesis. With more genes. polyploid plants might be better at capturing the limited light that remains. giving them a foothold when other plant lineages falter.
Taken together, the findings paint polyploidy as something like an insurance policy. “Most of the time, they fade away,” Van de Peer says, but during periods of extreme turmoil, they can “win out.” The work was published in the journal Cell.
There’s an urgency behind that conclusion that reaches beyond deep time. The planet is again facing a changing climate—one that may push ecosystems into unfamiliar conditions. Plant biotechnologist Sandra Pitta at the University of Buenos Aires. who wasn’t involved in the study. said the paper is “rigorous” and offers “hope. ” especially for practical efforts to help crops endure stress.
Pitta focuses on what breeders could do with the idea: “If polyploidism help them resist more different types of stresses,” she says, “well, that is really useful.”
For Van de Peer, the study also carries something more personal than scientific payoff. After years spent trying to solve the “polyploid paradox. ” he describes the sense that the work has finally found its end point. “I feel like I can retire now,” he says, calling it the culmination of 25 years of work.
Still, the bigger message is about how survival can look—how a genetic feature that often fails under normal conditions can become a lifeline when the rules of the environment are rewritten. Sometimes, a dead end doesn’t stay one. Sometimes it becomes the way forward.
polyploidy genome duplication flowering plants climate change environmental upheaval asteroid impact 66 million years ago Ghent University Yves Van de Peer Cell journal plant breeding photosynthesis