Extreme low temperature tolerance in woody plants

Abstract

Woody plants in boreal to arctic environments and high mountains survive prolonged exposure to temperatures below -40°C and minimum temperatures below -60°C, and laboratory tests show that many of these species can also survive immersion in liquid nitrogen at -196°C. Studies of biochemical changes that occur during acclimation, including recent proteomic and metabolomic studies, have identified changes in carbohydrate and compatible solute concentrations, membrane lipid composition, and proteins, notably dehydrins, that may have important roles in survival at extreme low temperature (ELT). Consideration of the biophysical mechanisms of membrane stress and strain lead to the following hypotheses for cellular and molecular mechanisms of survival at ELT: (1) Changes in lipid composition stabilize membranes at temperatures above the lipid phase transition temperature (-20 to -30°C), preventing phase changes that result in irreversible injury. (2) High concentrations of oligosaccharides promote vitrification or high viscosity in the cytoplasm in freeze-dehydrated cells, which would prevent deleterious interactions between membranes. (3) Dehydrins bind membranes and further promote vitrification or act stearically to prevent membrane–membrane interactions.

Parallels between natural selection in the cold‐adapted crop‐wild relative Tripsacum dactyloides and artificial selection in temperate adapted maize

“…The identification of accelerated protein sequence evolution among genes involved in phospholipid metabolism provides a plausible candidate mechanism for the increased cold and freezing tolerance of T. dactyloides relative to maize. Membrane lipid fatty acid composition is known to be associated with variability in cold and freezing tolerance in several plant species including maize, wheat, solanum species, and woody plants (Vigh et al ., ; Palta et al ., ; Kaniuga et al ., ; Strimbeck et al ., ) While relatively mild transcriptional differences in the expression phospholipid metabolism genes were observed among the species tested, the changes in phospholipid desaturation were statistically and biology significant, particularly for PC. This may be because of the high flux of PC during lipid metabolism (Burgos et al ., ).…”

Chilling and forcing temperatures interact to predict the onset of wood formation in Northern Hemisphere conifers

“…Even if the CiHS model has no clear mechanistic foundation, we remind that the exposure to chilling temperature promotes soluble sugars accumulation from starch conversion, especially sucrose (along with raffinose, stachyose and other metabolites; Sakai & Larcher, ; Strimbeck, Schaberg, Fossdal, Schröder, & Kjellsen, ) that remain high until spring dehardening. Since cell production is limited by local sucrose availability (Deslauriers, Huang, Balducci, Beaulieu, & Rossi, ), we posit that exposure to chilling temperatures may constitute a local pool of sucrose readily available for cell production when temperatures become favourable for mitosis and/or cell expansion.…”

First evidence of freezing tolerance in a resurrection plant: insights into molecular mobility and zeaxanthin synthesis in the dark

“…So far, the possibility of leaf vitrification upon freezing had been suggested (Strimbeck and Schaberg , Strimbeck et al ) but very scarce measurements in photosynthetic tissues, i.e. leaves, had been conducted and most of them were performed through low accuracy methodologies such as DSC (Hirsh ).…”