Changing winter climate and snow conditions induce various transcriptional stress responses in Scots pine seedlings

Abstract

In northern boreal forests the warming winter climate leads to more frequent snowmelt, rain-on-snow events and freeze-thaw cycles. This may be harmful or even lethal for tree seedlings that spend even a half of the year under snow. We conducted a snow cover manipulation experiment in a natural forest to find out how changing snow conditions affect young Scots pine (Pinus sylvestris L.) seedlings. The ice encasement (IE), absence of snow (NoSNOW) and snow compaction (COMP) treatments affected ground level temperature, ground frost and subnivean gas concentrations compared to the ambient snow cover (AMB) and led to the increased physical damage and mortality of seedlings. The expression responses of 28 genes related to circadian clock, aerobic and anaerobic energy metabolism, carbohydrate metabolism and stress protection revealed that seedlings were exposed to different stresses in a complex way depending on the thickness and quality of the snow cover. The IE treatment caused hypoxic stress and probably affected roots which resulted in reduced water uptake in the beginning of the growing season. Without protective snowpack in NoSNOW seedlings suffered from cold and drought stresses. The combination of hypoxic and cold stresses in COMP evoked unique transcriptional responses including oxidative stress. Snow cover manipulation induced changes in the expression of several circadian clock related genes suggested that photoreceptors and the circadian clock system play an essential role in the adaptation of Scots pine seedlings to stresses under different snow conditions. Our findings show that warming winter climate alters snow conditions and consequently causes Scots pine seedlings various abiotic stresses, whose effects extend from overwintering to the following growing season.

The genetic and environmental variance of radial increment in Scots pine of south-eastern Baltic provenances in response to weather extremes

“…The lagged peaks in the heritability estimates after the PYs (Figure 3) implied that the growth recovery potential has been subjected to the local genetic adaptation (Moran et al 2017); though, tolerance analysis was not performed due to inconsistency of the lags (Schwarz et al 2020). The synergic effect of weather anomalies on the heritability estimates (Figure 3) complied with the multifactorial regulation of the growth plasticity and recovery (efficiency and period) (Pennacchi et al 2021, Vuosku et al 2022. Accordingly, local genetic adaptation can be related to cumulative weather effects and hence the ability to cope with multiple stresses (Ansarifar et al 2020, Chmura et al 2021, which have likely contributed to productivity (Way and Oren 2010) and are increasingly important under the anticipated climatic changes (Li et al 2017).…”

“…Accordingly, local genetic adaptation can be related to cumulative weather effects and hence the ability to cope with multiple stresses (Ansarifar et al 2020, Chmura et al 2021, which have likely contributed to productivity (Way and Oren 2010) and are increasingly important under the anticipated climatic changes (Li et al 2017). The multifactorial genetic controls under optimal growing conditions (de la Mata et al 2022, Vuosku et al 2022 have likely caused the estimates of H 2 and CVP to be intermediate and low, respectively. The low heritability estimated at the PYs (Figure 3) implied uniform resistance of increment of the local populations to growth changes, supporting the regional synchronization of sensitivity (Cavin and Jump 2017).…”

Influence of Additional White, Red and Far-Red Light on Growth, Secondary Metabolites and Expression of Hormone Signaling Genes in Scots Pine under Sunlight

“…It can be assumed that the previous-year shoot of a plant formed under natural light and temperature conditions remembers this phenomenon at the molecular level. Moreover, winter dormancy can lead to the elimination of photoreceptor signals, and the greatest effect can be observed on young needles [38]. Considering that the set of PHYs of conifers differs from that of flowering plants, it can be expected that the reception of RL and FRL is carried out by different types of PHYs, in contrast to some liver mosses, where there is one type of PHY and whose functions have not yet been elucidated [1].…”