Timing of bud set in Picea abies is regulated by a memory of temperature during zygotic and somatic embryogenesis. New Phytol

Norwegian Forest and Landscape Institute, PO Box 115, NO-1431 As, Norway.
New Phytologist (Impact Factor: 7.67). 02/2008; 177(1):49-59. DOI: 10.1111/j.1469-8137.2007.02222.x
Source: PubMed


It has been shown previously that height growth and bud phenology are influenced by the temperature during zygotic embryogenesis in Picea abies. To test whether this phenomenon operates within individual plants, clones produced through somatic embryogenesis were used. Seeds were from a full-sib family produced in both a cold (outdoor) and a warm (inside a glasshouse) environment. Embryogenic clones derived from mature zygotic embryos from both crossing environments were cultured at 18, 23 and 28 degrees C during the proliferation and embryo maturation steps. After the second growing season in a glasshouse, plants from the warm seed production environment were taller and had significantly later bud set. For the first time, it is also shown that plants are influenced by the in vitro temperature during somatic embryo development. The warmer the temperature, the later the plants formed terminal buds. The differences were similar to those produced by a provenance separation of 4-6 degrees of latitude. The results indicate that there exists a mechanism in P. abies that operates during embryo development and adjusts the timing of bud set in accordance with the temperature conditions in which the mother tree lives. This in turn counteracts negative effects of gene flow among populations located along altitudinal and latitudinal gradients.

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    • "Somatic mutation in plants, including woody species, could arise from genetic (Kobayashi et al., 2004; Venturi et al., 2006; Nwafor et al., 2014; Otto et al., 2014) or epigenetic (Kvaalen and Johnsen, 2008) changes. These mutants, almost identical to their parents in genetic background, are considered desirable genetic material to study the novel traits of mutation (Nwafor et al., 2014; Otto et al., 2014). "
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    • "Tree molecular biology has seen tremendous advancements, particularly since the publication of the first tree genome (Tuskan et al. 2006, Wullschleger et al. 2013). We can now attribute the complex responses of trees to specific genetic (or epigenetic; Kvaalen and Johnsen 2008, Rohde and Junttila 2008) markers or even to single genes. For example, Garcés et al. (2014) propose candidate genes for forward genetic approaches that can help us discover naturally occurring nucleotide variations associated with productivity and wood quality. "

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    • "Currently, the investigation started in Norway spruce, including transcriptional and microRNA changes between epitypes (Yakovlev et al. 2010, 2011). All evidence strongly suggests that epigenetic memory is established exclusively during the initial stages of embryo development in Norway spruce and involves no change in the primary DNA sequence (Kvaalen and Johnsen 2008). Therefore, we hypothesize that epigenetic memory mechanisms influence phenotype through altered regulation of gene expression impacted by mitotically propagated temperaturedependent chromatin modifications and non-coding RNA. "
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