How plants evolved a molecular switch to cope with heat

Ghent, 26 August – As climate change drives more frequent and intense heat waves, plants face growing challenges to survive and remain productive. Researchers at VIB, Ghent University, KU Leuven, and their international collaborators have now uncovered an evolutionary innovation that helps plants cope with high temperatures. Published in Nature Plants, the study uncovers a molecular mechanism that helps plants stay cool under heat stress and could help researchers identify new ways to strengthen crop resilience.

26/08/2026

In short:

Researchers led by Prof. Ive De Smet (VIB-UGent) discovered a molecular mechanism that helps plants stay cool during heat stress by keeping their natural cooling system active.
The study, published in Nature Plants, identifies the protein UBP24 as a key regulator that helps leaf pores (stomata) remain open, allowing plants to cool themselves through evaporation.
The mechanism appears to be an evolutionary innovation that emerged alongside actively controlled stomata, helping plants better adapt to rising temperatures.
The findings provide new insights into plant heat resilience and could support future efforts to develop crops better equipped for climate change and more frequent heat waves.

Keeping cool when temperatures rise

Unlike animals, plants cannot move to a cooler location when temperatures soar. Instead, they rely on built-in mechanisms to avoid overheating.

One of the most important cooling mechanisms involves tiny pores on the leaf surface called stomata. When temperatures increase, these pores can open, allowing water to evaporate and cool the leaf, much like how sweating cools the human body. Scientists have long known that stomata help plants cope with heat, but many of the underlying molecular processes remained poorly understood.

Led by Prof. Ive De Smet (VIB-UGent Center for Plant Systems Biology), the researchers – including the teams of Prof. Kevin Verstrepen (VIB-KU Leuven Center for Microbiology) and Prof. Kris Gevaert (VIB-UGent Center for Medical Biotechnology) - discovered a previously unknown pathway that helps stomata open during heat stress. Central to this mechanism is a protein called UBP24. High temperatures trigger a modification that stabilizes UBP24. This change stabilizes other proteins that keep stomata open and maintain the plant’s natural cooling system.

Towards more resilient crops

Understanding how plants respond to heat is becoming increasingly important as temperatures continue to rise worldwide. The newly discovered mechanism helps explain how plants keep their leaves cool under hot conditions. While the research is fundamental in nature, it provides new insight into the biological processes that support heat resilience in plants and could eventually inform efforts to develop more climate-resilient crops.

“As heat waves become more frequent and intense, understanding how plants naturally cope with high temperatures is more important than ever,” says Prof. Ive De Smet. “By uncovering one of the mechanisms plants use to regulate their cooling system, we gain new insights into the biological processes that help plants remain resilient under heat stress.”

An evolutionary innovation

By comparing UBP24 across dozens of plant species, the researchers discovered that a molecular switch enabling the protein to respond to heat appeared in vascular plants around the same time that actively controlled stomatal opening and closing evolved. This seemingly small change gave plants a new way to fine-tune their response to heat.

Surprisingly, the story extends beyond plants. The team found that a related protein in yeast relies on a similar principle to function under heat stress, despite hundreds of millions of years of evolutionary distance between the two organisms.

“Finding similar solutions in organisms as different as plants and yeast was particularly exciting,” says first author Shao-Li Yang (VIB-UGent). “It suggests that this is a remarkably ancient and effective way for cells to deal with heat.”

As climate change increases the frequency and intensity of heat waves, understanding how plants naturally cope with high temperatures is becoming ever more important. By uncovering a molecular switch that helps plants regulate their cooling system, the researchers reveal one of the ways plants have adapted to life in a changing environment. These insights not only deepen our understanding of plant evolution but may also guide future efforts to develop crops that are better prepared for a warming world.

Publication

Yang et al. Evolutionary tuning of molecular charge state of UBP24 shapes responses to high temperature. Nature Plants (2026).

Funding

This research was supported by the Research Foundation – Flanders (FWO), the Taiwanese Government Scholarship to Study Abroad, Ghent University Special Research Fund (BOF), and the China Scholarship Council. Additional support was provided by the Knut and Alice Wallenberg Foundation and through the long-term program PlantXR: A new generation of breeding tools for extra-resilient crops, carried out within the CropXR Institute.