Induced cold tolerance mechanisms depend on duration of acclimation in the chill sensitiveFolsomia candida(Collembola)

Abstract

SUMMARYDuring cold periods ectotherms may improve low temperature tolerance via rapid cold hardening (RCH) over a period of hours and/or long-term cold acclimation (LTCA) during days, weeks or months. However, the effect of duration and the major underlying mechanisms of these processes are still not fully understood. In the present study, the molecular and biochemical responses to RCH (1-3h) and LTCA (1-3days) and the corresponding benefits to survival were investigated using the chill-sensitive collembolan Folsomia candida. We investigated osmolyte accumulation, membrane restructuring and transcription of candidate genes as well as survival benefits in response to RCH and LTCA. RCH induced significant upregulation of targeted genes encoding enzymes related to carbohydrate metabolic pathways and genes encoding small and constitutively expressed heat shock proteins (Hsps), indicating that the animals rely on protein protection from a subset of Hsps during RCH and probably also LTCA. The upregulation of genes involved in carbohydrate metabolic processes initiated during RCH was likely responsible for a transient accumulation of myoinositol during LTCA, which may support the protection of protein and membrane function and structure. Membrane restructuring, composed especially of a significantly increased ratio of unsaturated to saturated phospholipid fatty acids seems to be a mechanism supplementary to activation of Hsps and myoinositol accumulation in LTCA. Thus, the moderate increase in cold shock tolerance conferred by RCH seems to be dominated by effects of Hsps, whereas the substantially better cold tolerance achieved after LTCA is dominated by post-transcriptional processes increasing membrane fluidity and cryoprotectant concentration.

Effects of within-generation thermal history on flight performance ofCeratitis capitata: colder is better

“…Kellett et al, 2005;Basson et al, 2012), throughout a developmental or adult stage (e.g. Kristensen et al, 2008;Fischer et al, 2010;Waagner et al, 2013), or over evolutionary timescales (among populations or between species, for examples see Gibert et al, 2001;Kelty and Lee, 2001;Steigenga and Fischer, 2007) can radically alter tolerance and performance under a given set of environmental conditions. Moreover, it is increasingly clear that the different timescales of thermal exposure may result in different underlying responses and mechanisms (e.g.…”

“…Moreover, it is increasingly clear that the different timescales of thermal exposure may result in different underlying responses and mechanisms (e.g. Colinet and Hoffmann, 2012;Teets and Denlinger, 2013;Waagner et al, 2013).…”

Differential expression patterns of two delta‐9‐acyl‐CoA desaturases in Thitarodes pui (Lepidoptera: Hepialidae) during different seasons and cold exposure

“…In that study, twofold to tenfold up‐regulation of the D9D gene was induced in brain tissues, malpighian tubules, and the midgut when D. antique was exposed to cold (Kayukawa et al., 2007). This same result occurred in Sarcophaga crassipalpis (Rinehart, Robich, & Denlinger, 2010), Folsomia candida (Waagner, Holmstrup, Bayley, & Jesper, 2013), and Aedes albopictus (Reynolds et al. 2012).…”

“…(2007) proved that the expression of D9D increased to enhance the cold hardiness in Delia antiqua through up‐regulating the abundance of C16:1 and C18:1. So far, the same results were seen in S. crassipalpis (Rinehart et al., 2010), A. albopictus (Reynolds, Poelchau, Rahman, Armbruster, & Denlinger, 2012) and F. candida (Waagner et al., 2013). At the same time, seasonal cold‐hardening is defined as cold‐hardening that requires at least days to weeks for induction (Teets & Denlinger, 2013).…”

Membrane properties of Enchytraeus albidus originating from contrasting environments: a comparative analysis

“…Samples used for measurements of fluorescence anisotropy and bending rigidity were not extracted further than this step. Samples used for PLFA analysis were evaporated under N 2 after which phospholipids were trans-esterified by a mild alkaline methanolysis (Dowling et al 1986;Waagner et al 2013b) and dried again under N 2 . Finally the fatty acid methyl esters (FAME) were re-dissolved in heptane for further analysis.…”