Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: August 15, 2012
Publication Date: September 30, 2012
Citation: Wisniewski, M.E., Artlip, T.S., Norelli, J.L. 2012. Overexpression of a peach cbf-transcription factor gene in apple regulates both dormancy and freezing tolerance in apple. Rosacease Genomics Conference. p. 45. Technical Abstract: Economic production of fruit trees in a temperate climate is dependent upon seasonal changes in cold acclimation and dormancy. Evidence indicates that these processes will be greatly affected by climate change (higher atmospheric carbon dioxide and temperatures). This problem may also be exacerbated by erratic weather patterns. Weather events in the USA in the spring of 2012, resulting in devastating losses to fruit crops, are an example of the potential danger. Wisniewski, et al. (2010. Planta 233:971-983) previously demonstrated that a transgenic ‘M.26’ apple line (T166) overexpressing a peach CBF gene increased the freezing tolerance and induced earlier dormancy (Wisniewski, et al. 2010. Planta 233:971-983). Since that study, the field performance of T166 has been monitored in comparison wt (‘M.26’), and apple lines in which expression of a native CBF has been suppressed (CBF-Si). Self-rooted trees were planted on October 7, 2010, and several phenotypic characteristics monitored. The T166 line exhibited an immediate response to cool temperatures and short photoperiod. Trees exhibited a large increase in anthocyanins in their leaves followed by rapid senescence. By November 4, 2010, T166 trees had lost all their leaves, while wt and CBF-Si trees still had green leaves. In spring of 2011, the CBF-Si line was the first to break buds prior to the wt trees. T166 trees leafed out last. Mean date of leaf emergence varied by about two weeks between the three lines. Growth (shoot growth and main stem diameter) was lowest in the T166 line. In 2011, the fall pattern of leaf senescence and drop was similar to 2010. Thus, it appears that overexpression of a peach CBF gene in apple has significant, long-term effects on several phenological events in apple. Observations for 2012 support these conclusions.