Cultured tobacco cells (Nicotiana tabacum L. var Wisconsin-38) developed tolerance to otherwise nonpermissive 54 degrees C treatment when heat-shocked at 38 degrees C (2 h) but not at 42 degrees C. Heat-shocked cells (38 degrees C) exhibited little normal growth when the 54 degrees C stress came immediately after heat shock and normal growth when 54 degrees C stress was administered 8 hours aft...

This work tested the hypotheses that splanchnic oxidant generation is important in determining heat tolerance and that inappropriate.NO production may be involved in circulatory dysfunction with heat stroke. We monitored colonic temperature (T(c)), heart rate, mean arterial pressure, and splanchnic blood flow (SBF) in anesthetized rats exposed to 40 degrees C ambient temperature. Heating rate, ...

Recent research has suggested a potential for some of the physiological and cellular responses to heat acclimation to carry over to improved tolerance of the novel stresses of another environment. This cross-tolerance is evident in heat-acclimated animals that exhibit enhanced tolerance to either hypoxic or ischemic stress, and is primarily attributed to shared cellular stress response pathways...

Heat stress poses a serious threat to global crop production. In efforts that aim to mitigate the adverse effects of heat stress on crops, a variety of genetic tools are being used to develop plants with improved thermotolerance. The characterization of important regulators of heat stress tolerance provides essential information for this aim. In this study, we examine the wheat (Triticum aestiv...

Introduction The common practice in the Israel Defense Force is that all exertional heat related injuries victims undergo a heat tolerance test (HTT) as a part of the "return to duty" process. The purpose of this study was to develop a quantitative, supportive physiological index for the assessment of the HTT based on the understanding that heat strain level should combine the thermal and cardi...

Environmental stress tolerance is an important trait for crop improvement. In recent decades, numerous genes that confer tolerance to abiotic stress such as salinity were reported. However, the levels of salt tolerance differ greatly depending on growth conditions, and mechanisms underlying the complicated nature of stress tolerance are far from being fully understood. In this study, we investi...

We have examined the cell cycle specificity of 45.5 degrees heat-induced toxicity and the induction and expression of thermal tolerance. Ultrapure populations of G1-, S-, and G2-M-phase cells were obtained through sequential centrifugal elutriation and flow cytometric cell sorting of Hoechst 33342-stained cells. We found no interaction of Hoechst 33342 with hyperthermia under staining condition...

1. Researchers commonly rely on indices of heat tolerance to infer the limits of performance in nature. Unfortunately, many methods are used to estimate heat tolerance, creating difficulties when synthesizing or comparing results among studies. Here, we relate several measures of heat tolerance based on the concept of a performance curve. 2. To evaluate our ideas about the link between two meas...

Heat stress commonly leads to inhibition of photosynthesis in higher plants. The transcriptional induction of heat stress-responsive genes represents the first line of inducible defense against imbalances in cellular homeostasis. Although heat stress transcription factor HsfA2 and its downstream target genes are well studied, the regulatory mechanisms by which HsfA2 is activated in response to ...

Thermal tolerance is an important factor influencing the distribution of ectotherms, but we still have limited understanding of the ability of species to evolve different thermal limits. Recent studies suggest that species may have limited capacity to evolve higher thermal limits in response to slower, more ecologically relevant rates of warming. However, these conclusions are based on univaria...