Winter dormancy has long been used to explain how temperate fruit trees survive cold seasons and time spring growth. In this classic view, buds enter a largely repressed state until sufficient chilling and warmer conditions allow growth to resume. Yet this framework has struggled to explain why different bud types in the same tree behave so differently. In peach, flower buds continue slow internal development through winter, while vegetative buds have usually been treated as dormant by default. At the same time, climate change is making seasonal signals less predictable, raising urgent questions about how buds sense and respond to cold. Based on these challenges, deeper research is needed on organ-specific winter development in perennial buds.
Researchers from the University of Padova, the University of Milan, Sequentia Biotech, and IBMCP-CSIC/Universitat Politècnica de València reported (DOI: 10.1093/hr/uhaf310) on November 6, 2025, in Horticulture Research that peach vegetative and flower buds remain molecularly active through winter but rely on different regulatory networks to coordinate development under cold and changing day length.
The team studied peach buds across multiple chilling timepoints using an integrated workflow. Microscopic sections showed that vegetative buds continued differentiating through winter, with expanding meristematic regions and leaflet development, providing direct structural evidence that these buds are active rather than fully arrested. Hormone analysis then revealed a surprise: vegetative and flower buds displayed broadly similar levels of ABA and active GA4, suggesting that hormone abundance alone could not explain their different behaviors. Transcriptome profiling confirmed that the real divergence lay in gene regulation. Vegetative buds preferentially activated jasmonate- and photoperiod-responsive modules, while flower buds were dominated by chilling-responsive modules. Network analysis further showed that SVP1 became a highly connected hub in flower buds, whereas vegetative buds maintained a different wiring pattern enriched in jasmonate signaling and meristem regulators. Experimental interaction assays added a mechanistic layer, confirming that SVP1 physically interacted with DAM3, DAM5, and DAM6. Gene regulatory network reconstruction then showed distinct combinations of regulators: DAM5 and DAM6 homodimers predominated in vegetative buds, while DAM4 together with SVP1/2 heterodimers was more prominent in flower buds.
“Our findings support a revised model of dormancy,” the authors concluded, arguing that DAM and SVP proteins act less like rigid off-switches and more like flexible transcriptional modulators working in bud-specific regulatory landscapes. In that view, winter buds are not simply asleep. They are actively interpreting cold, day length, and internal signals in ways that differ by organ and developmental fate.
The implications reach beyond peach. As warmer winters disrupt chilling accumulation and spring timing, fruit production increasingly depends on understanding how different buds make developmental decisions under unstable climates. This study offers a new framework for explaining why vegetative and floral tissues can respond differently even within the same tree. It also points to specific regulatory targets, including GASA1, GASA6, and EMF1, that may help breeders and biologists better understand bud resilience, flowering timing, and adaptation in perennial crops. By replacing a one-size-fits-all dormancy model with a more dynamic view, the work opens a clearer path toward predicting and managing climate-sensitive orchard performance.
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References
DOI
10.1093/hr/uhaf310
Original Source URL
https://doi.org/10.1093/hr/uhaf310
Funding information
This work was funded by BIRD 2019 and 2020-University of Padova with a grant to BC and SV.
About Horticulture Research
Horticulture Research is an open access journal of Nanjing Agricultural University and ranked number one in the Horticulture category of the Journal Citation Reports ™ from Clarivate, 2023. The journal is committed to publishing original research articles, reviews, perspectives, comments, correspondence articles and letters to the editor related to all major horticultural plants and disciplines, including biotechnology, breeding, cellular and molecular biology, evolution, genetics, inter-species interactions, physiology, and the origination and domestication of crops.