EARLY BUD-BREAK 1 (EBB1) is a regulator of release from seasonal dormancy in poplar trees Public Deposited


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  • Trees from temperate latitudes transition between growth and dormancy to survive dehydration and freezing stress during winter months. We employed activation tagging to isolate a dominant mutation affecting release from dormancy, and identified the corresponding gene EARLY BUD-BREAK 1 (EBB1). We demonstrate through positioning of the tag, expression analysis, and retransformation experiments that EBB1 encodes a putative AP2/ERF transcription factor. Transgenic upregulation of the gene caused early bud-flush, while down-regulation delayed bud-break. Native EBB1 expression was highest in actively-growing apices, undetectable during the dormancy period, but rapidly increased prior to bud-break. The EBB1 transcript was localized in the L1/L2 layers of the shoot meristem and leaf primordia. EBB1-overexpressing transgenic plants displayed enlarged shoot meristems, open and poorly differentiated buds, and a higher rate of cell division in the apex. Transcriptome analyses of the EBB1 transgenics identified 971 differentially-expressed genes whose expression correlated with the EBB1 expression changes in the transgenic plants. Promoter analysis among the differentially expressed genes for presence of a canonical EBB1 binding site identified 65 putative target genes indicative of a broad regulatory context of EBB1 function. Our results suggest that EBB1 has a major and integrative role in reactivation of meristem activity after winter dormancy.
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  • Yordanov, Y. S., Ma, C., Strauss, S. H., & Busov, V. B. (2014). EARLY BUD-BREAK 1 (EBB1) is a regulator of release from seasonal dormancy in poplar trees. Proceedings of the National Academy of Sciences, 111(27), 10001-10006. doi:10.1073/pnas.1405621111
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  • 111
Journal Issue/Number
  • 27
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  • This research was supported, in part, by grants from the Office of Science Biological and Environmental Research (BER) program at the US Department of Energy (Grants DE-FG02-06ER64185, DE-FG02-05ER64113, and DE-SC0008462); US Department of Agriculture (USDA)-National Resources Inventory Plant Genome Program (Grant 2003-04345); Consortium for Plant Biotechnology Research, Inc. (Grant GO12026-203A); USDA Biotechnology Risk Assessment Research Grants Program (Grant 2004-35300-14687); USDA McIntire Stennis Fund (Grant 1001498); and industrial members of the Tree Biosafety and Genomics Research Cooperative at Oregon State University.
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