BACKGROUND AND AIMS Woody plants can suffer from winter embolism as gas bubbles are formed in the water-conducting conduits when freezing occurs: gases are not soluble in ice, and the bubbles may expand and fill the conduits with air during thawing. A major assumption usually made in studies of winter embolism formation is that all of the gas dissolved in the xylem sap is trapped within the con...

Winter wheat (Triticum aestivum L. em. Thell.) is sown in the autumn and harvested the following summer, and therefore must survive subfreezing temperatures for several months. Because of autumn rains and winter snows, the plants usually are subjected to these subfreezing temperatures while growing in saturated soil. As the plants freeze, they are subjected to freezing episodes that may vary in...

During cold acclimation, winter rye (Secale cereale L. cv Musketeer) plants accumulate antifreeze proteins (AFPs) in the apoplast of leaves and crowns. The goal of this study was to determine whether these AFPs influence survival at subzero temperatures by modifying the freezing process or by acting as cryoprotectants. In order to inhibit the growth of ice, AFPs must be mobile so that they can ...

Winter warming and its accompanying predicted decrease in snow pack for northern temperate regions may increase frost damage to plants induced by an increase in freeze-thaw cycles (FTCs) due to reduced insulation. FTC frequency, minimum temperature during freezing and pre-existing local adaptations potentially all influence site-specific plant responses to future climatic changes. Within a cham...

Seasonal changes in freezing stress resistance of needles of red pine (Pinus resinosa Ait.) and Austrian pine (Pinus nigra Arnold) trees were measured by an electrolyte leakage method and by visual observation. During most of the year, freezing stress resistance determined by the two methods gave similar results. The electrolyte leakage method provided a good estimate of seasonal changes in fre...

Hatchlings of the painted turtle (Chrysemys picta marginata) are unique as the only reptile and highest vertebrate life form known to tolerate the natural freezing of extracellular body fluids during winter hibernation. Turtles survived frequent exposures to temperatures as low as -6 degrees C to -8 degrees C in their shallow terrestrial nests over the 1987-1988 winter. Hatchlings collected in ...

Time-courses of the development of freezing tolerance and the expression of a cold-responsive gene wlt10 were monitored during cold acclimation in wheat (Triticum aestivum L.). Bioassay showed that cold acclimation conferred much higher freezing tolerance on a winter cultivar than a spring cultivar. Northern blot analysis showed that the expression of wlt10 encoding a novel wheat member of a ce...

Many species show changes in distribution and phenotypic trait variation in response to climatic warming. Evidence of genetically based trait responses to climate change is, however, less common. Here, we detected evolutionary variation in the landscape-scale distribution of a genetically based chemical polymorphism in Mediterranean wild thyme (Thymus vulgaris) in association with modified extr...

Ectotherms overwintering in temperate ecosystems must survive low temperatures while conserving energy to fuel post-winter reproduction. Freeze-tolerant wood frogs, Rana sylvatica, have an active response to the initiation of ice formation that includes mobilising glucose from glycogen and circulating it around the body to act as a cryoprotectant. We used flow-through respirometry to measure CO...

Our long-term goal is to develop a Swedish winter oat (Avena sativa). To identify molecular differences that correlate with winter hardiness, a winter oat model comprising of both non-hardy spring lines and winter hardy lines is needed. To achieve this, we selected 294 oat breeding lines, originating from various Russian, German, and American winter oat breeding programs and tested them in the ...