The Evergreen Challenge: How Pine Trees Survive Winter

Conifers, like the Pinus tabuliformis, have a tough job. They must deal with cold and dry conditions during autumn and winter. These evergreen trees do not shed their leaves, so they face unique challenges. Understanding how they manage growth and stress is key to protecting forests and improving tree genetics in a changing climate. Scientists have found that a protein called TFL2 plays a big role in helping conifers handle these stresses. TFL2 helps trees go dormant, or rest, at the right time of year. Its activity changes with the seasons, but how it does this has been a mystery. To solve this, researchers looked at all the proteins that interact with TFL2. They found 448 unique proteins, including many that help control gene activity. Among these proteins, two stood out: PtbZIP43 and PtERF21. These proteins work directly with TFL2 and follow a similar pattern of activity throughout the year. They peak in autumn, creating a chain reaction that helps trees prepare for winter. This chain, or module, helps trees manage growth and stress by turning on specific genes at the right time. When scientists increased the activity of TFL2, PtbZIP43, and PtERF21 in trees, they found that the trees flowered later and were better at handling cold and dry conditions. This shows that the module helps trees survive the stresses of autumn and winter. The findings reveal how conifers use a complex network of proteins to adapt to seasonal changes and stress. This knowledge could help improve the resilience of forest trees in the face of climate change.