Freezing dynamics and injury in overwintering buds

Climate change is altering the environmental conditions that determine plant survival and productivity. Warmer temperatures may extend growing seasons, but disrupt the seasonal signals that perennial plants depend on for winter survival and spring development.

This project focuses on cold hardiness of overwintering buds – a dynamic physiological trait that lets plants survive freezing temperatures. Temperate perennial plants build up cold hardiness through cold acclimation in autumn, reaching maximum hardiness in mid-winter, and lose it again through dehardening in spring. The catch: warmer winters do not necessarily reduce frost risk. Instead, they may expose sensitive tissues to freezing at their most vulnerable developmental stages – threatening forestry, viticulture, fruit production, and food systems.

At its core, this project seeks a fundamental physiological understanding of how buds actually tolerate freezing. We follow the ice itself: where it forms, how it spreads, and how protective ice barriers keep it away from the most sensitive tissues. Using high-resolution thermal methods, microscopy, and metabolomics, we link a bud's structure, water relations, and biochemistry to its ability to withstand the cold.

By building this mechanistic foundation, the project aims to contribute to better frost-risk prediction, inform the breeding of cold-resilient crops and trees, and support forecasts of how ecosystems respond to a changing climate.