Temperature-driven plasticity in growth cessation and dormancy development in deciduous woody plants: a working hypothesis suggesting how molecular and cellular function is affected by temperature during dormancy induction

Abstract

The role of temperature during dormancy development is being reconsidered as more research emerges demonstrating that temperature can significantly influence growth cessation and dormancy development in woody plants. However, there are seemingly contradictory responses to warm and low temperature in the literature. This research/review paper aims to address this contradiction. The impact of temperature was examined in four poplar clones and two dogwood ecotypes with contrasting dormancy induction patterns. Under short day (SD) conditions, warm night temperature (WT) strongly accelerated timing of growth cessation leading to greater dormancy development and cold hardiness in poplar hybrids. In contrast, under long day (LD) conditions, low night temperature (LT) can completely bypass the short photoperiod requirement in northern but not southern dogwood ecotypes. These findings are in fact consistent with the literature in which both coniferous and deciduous woody plant species' growth cessation, bud set or dormancy induction are accelerated by temperature. The contradictions are addressed when photoperiod and ecotypes are taken into account in which the combination of either SD/WT (northern and southern ecotypes) or LD/LT (northern ecotypes only) are separated. Photoperiod insensitive types are driven to growth cessation by LT. Also consistent is the importance of night temperature in regulating these warm and cool temperature responses. However, the physiological basis for these temperature effects remain unclear. Changes in water content, binding and mobility are factors known to be associated with dormancy induction in woody plants. These were measured using non-destructive magnetic resonance micro-imaging (MRMI) in specific regions within lateral buds of poplar under SD/WT dormancing inducing conditions. Under SD/WT, dormancy was associated with restrictions in inter- or intracellular water movement between plant cells that reduces water mobility during dormancy development. Northern ecotypes of dogwood may be more tolerant to photoinhibition under the dormancy inducing LD/LT conditions compared to southern ecotypes. In this paper, we propose the existence of two separate, but temporally connected processes that contribute to dormancy development in some deciduous woody plant: one driven by photoperiod and influenced by moderate temperatures; the other driven by abiotic stresses, such as low temperature in combination with long photoperiods. The molecular changes corresponding to these two related but distinct responses to temperature during dormancy development in woody plants remains an investigative challenge.

Temperate and boreal forest tree phenology: from organ-scale processes to terrestrial ecosystem models

“…The timing of bud-set closely follows the cessation of primary shoot growth (Gyllenstrand et al 2007;Rohde et al 2011). It is often assumed that the autumnal cessation of primary meristem activity and bud-set are fully controlled by the photoperiod (detected by the phytochrome receptor) in the majority of temperate tree species (Tanino et al 2010;Way 2011). However, recent experimental studies have demonstrated that temperature additionally modulates the timing of bud-set and the cessation of primary growth in a number of temperate and boreal tree species (e.g., Salminen and Jalkanen 2007), with both temperature and photoperiod acting in an interactive, non-monotonous manner (Rohde et al 2011;Heide 2011).…”

Regulation of Bud Dormancy and Bud Break in Japanese Apricot (Prunus mume Siebold ^|^amp; Zucc.) and Peach [Prunus persica (L.) Batsch]: A Summary of Recent Studies

“…However, we must keep in mind that programmed genetic systems of bud dormancy regulation may not necessarily be the same among the diverse plant species that exhibit bud dormancy, even though most perennial woody plants have adapted and evolved dormancy for survival. In addition, primary environmental cues that trigger the bud phenology cycle, such as the induction of bud set (or shoot tip abortion), vary depending on a given plant species (Tanino et al, 2010). Accordingly, the characterization of molecular networks regulating the dormancy of various woody species is being carried out by omics studies that use the target plants themselves.…”

Elevated temperature and CO2 stimulate late season photosynthesis but impair cold hardening in pine

“…In contrast, a recent study showed that smaller temperature increments (+1.5°C to +3°C) applied using infrared heaters did not delay down-regulation of photosynthesis or impair freezing tolerance in field-grown P. strobus seedlings that were acclimated to larger diurnal and seasonal temperature variations . For many tree species, photoperiod determines cessation of growth (Tanino et al, 2010;Petterle et al, 2013), length of the growing season (Bauerle et al, 2012), and development of cold hardiness (Welling et al, 1997;Li et al, 2003;Rostad et al, 2006). However, the effects of climate warming on tree phenology are complex and can be unpredictable due to species-and provenancespecific differences in sensitivity to photoperiod and temperature cues (Körner and Basler, 2010;Basler and Körner, 2012;Basler and Körner, 2014).…”