Herbaceous temperate plants are capable of developing freezing tolerance when they are exposed to low nonfreezing temperatures. Acquired freezing tolerance involves extensive reprogramming of gene expression and metabolism. Recent full-genome transcript profiling studies, in combination with mutational and transgenic plant analyses, have provided a snapshot of the complex transcriptional networ...

doi: 10.1111/j.1399-3054.2006.00644.x Previous studies indicate that conifers are vulnerable to cavitation induced by drought but in many cases, not by freezing. Rarely have vulnerability to drought and freezing stress been studied together, even though both influence plant physiology and the abundance and distribution of plants in many regions of the world. We studied vulnerability to droughta...

Plants are always exposed to various stresses. We have focused on freezing stress, which causes serious problems for agricultural management. When plants suffer freeze-induced damage, the plasma membrane is thought to be the primary site of injury because of its central role in regulation of various cellular processes. Cold tolerant species, however, adapt to such freezing conditions by modifyi...

In this study postmortem changes in the character of the stress-strain limit cycle were analyzed for cat extensor communis and extensor lateralis tendons maintained in a stream of Ringer’s solution and loaded with a short series of symmetrical triangular-wave stress cycles. The mechanical behavior of these tendons was compared with that of similar tendons which had been preserved by freezing. I...

Plant freezing tolerance involves the prevention of lethal freeze-induced damage to the plasma membrane. We hypothesized that plant freezing tolerance involves membrane resealing, which, in animal cells, is accomplished by calcium-dependent exocytosis following mechanical disruption of the plasma membrane. In Arabidopsis thaliana protoplasts, extracellular calcium enhanced not only freezing tol...

Cold-acclimated plants acquire an additional 3-5 degrees C increase in freezing tolerance when exposed to -3 degrees C for 12-18 h before a freezing test (LT50) is applied. The -3 degrees C treatment replicates soil freezing that can occur in the days or weeks leading to overwintering by freezing-tolerant plants. This additional freezing tolerance is called subzero acclimation (SZA) to differen...

Alfalfa (Medicago sativa L.) is an important perennial forage, with high nutritional value, which is widely grown in the world. Because of low freezing tolerance, its distribution and production are threatened and limited by winter weather. To understand the complex regulation mechanisms of freezing tolerance in alfalfa, we performed transcriptome sequencing analysis under cold (4 °C) and freez...

background: leptin and its receptor are present in spermatozoa; however, the role of leptin in sperm function is still controversial. our present study aimed at demonstrating the effect of cryopreservation on sperm dna fragmentation (dnaf) and investigating the possible effects of sperm capacitation techniques and leptin in vitro incubation on frozen-thawed sperm dnaf and oxidative stress. meth...

Activated oxygen or oxygen free radicals have been implicated in a number of physiological disorders in plants including freezing injury. Superoxide dismutase (SOD) catalyzes the dismutation of superoxide into O2 and H2O2 and thereby reduces the titer of activated oxygen molecules in the cell. To further examine the relationship between oxidative and freezing stresses, the expression of SOD was...

The levels of endogenous polyamines have been shown to increase in plant cells challenged with low temperature; however, the functions of polyamines in the regulation of cold stress responses are unknown. Here, we show that the accumulation of putrescine under cold stress is essential for proper cold acclimation and survival at freezing temperatures because Arabidopsis (Arabidopsis thaliana) mu...