06/20/2014
Characterization of Poplar Budbreak Gene Enhances Understanding of Spring Regrowth
Timing of vegetative bud dormancy is an environmentally and economically important trait whose importance will grow due to rapid climate changes.
The Science
Trees in temperate climates undergo annual cycles of growth and dormancy corresponding to summer and winter seasons, a critical strategy that allows perennial plants to survive cold and dehydration during the winter months. These important transitions are controlled by photoperiod and temperature, but the exact mechanisms by which key physiological processes are initiated are still poorly understood. Researchers at Michigan Technological University and Oregon State University have identified and functionally characterized a gene in the bioenergy feedstock tree Populus called Early Bud-Break 1 (EBB1). EBB1 serves as a “master regulator” in the timing of spring growth reactivation, or budbreak. In addition, the protein encoded by EBB1 was found to function in many other processes critical to poplar survival, including nutrient cycling and root growth. These results enhance understanding of dormancy release in woody perennial plants and will enable new approaches for breeding trees better adapted to changing environments such as a warmer climate. The research was supported by the U.S. Department of Agriculture-Department of Energy Plant Feedstock Genomics for Bioenergy Program.
Summary
Researchers used activation tagging to isolate a dominant mutation affecting release from dormancy and identified the corresponding gene EARLY BUD-BREAK 1 (EBB1). Transgenic up-regulation of the gene caused early bud-flush, whereas down-regulation delayed bud-break. Native EBB1 expression was highest in actively growing apices, undetectable during the dormancy period, but rapidly increased before bud-break.
BER Program Manager
Kari Perez
U.S. Department of Energy, Biological and Environmental Research (SC-33)
Biological Systems Science Division
[email protected]
References
Yordanov, Y. S., C. Ma, S. H. Strauss, and V. G. Busov. 2014. “Early Bud-Break 1 (EBB1) is a Regulator of Release from Seasonal Dormancy in Poplar Trees,” Proceedings of the National Academy of Sciences (USA) 111(27), 10,001–6. DOI:10.1073/pnas.1405621111.