PubMed · 2026-03-09
Scientists discovered how aging pine trees develop progressively deeper winter dormancy: a trio of proteins forms a stable complex that raises the threshold required for spring awakening, explaining why centuries-old conifers are far more resistant to false-spring temperature spikes than young saplings.
The age-marker protein PtDAL1 is significantly upregulated in dormant buds of 3-year-old saplings compared to juvenile seedlings, establishing a molecular link between tree age and dormancy depth.
PtTFL2 (a dormancy-regulating gene) shows a strict inverse relationship with tree age — its expression declines as trees mature — even though PtDAL1 transcriptionally activates it, revealing a paradox resolved by post-transcriptional protein trapping.
PtDAL1 physically recruits a second protein (PtDAL21) to sequester PtTFL2 into a stable complex, overriding gene expression dynamics and elevating the dormancy-release threshold in adult trees.
