Leaf gas exchange and temperature response were measured to assess temperature acclimation within a tree canopy in climatically contrasting genotypes of Acer rubrum L. Over the course of two 50 d continuous periods, growth temperature was controlled within tree crowns and the steady-state rate of leaf gas exchange was measured. Data were then modelled to calculate the influence of genotype vari...

The effects of exogenously supplied isoprene on chlorophyll fluorescence characteristics were examined in leaf discs of four isoprene-emitting plant species, kudzu (Pueraria lobata [Willd.] Ohwi.), velvet bean (Mucuna sp.), quaking aspen (Populus tremuloides Michx.), and pussy willow (Salix discolor Muhl). Isoprene, supplied to the leaves at either 18 &mgr;L L-1 in compressed air or 21 &mgr;L L...

Many studies report that water flux through trees declines in response to elevated CO(2), but this response may be modified by exposure to increased temperatures. To determine whether elevated CO(2) and temperature interact to affect hydraulic conductivity, we grew ponderosa pine seedlings for 24 wk in growth chambers with one of four atmospheric CO(2) concentrations (350, 550, 750, and 1100 pp...

Anthropogenic forces are projected to lead to warmer temperatures and altered precipitation patterns globally. The impact of these climatic changes on the uptake of carbon by the land surface will, in part, determine the rate and magnitude of these changes. However, there is a great deal of uncertainty in how terrestrial ecosystems will respond to climate in the future. Here, we used a fully fa...

introduction major cultivated cotton regions of iran are located in dry and semiarid climates, therefore water deficiency or drought stress is inseparable part of cotton production systems in these regions. so identification and introduction of drought tolerant cotton genotypes is crucial. showed that water stress decreased plant growth rate, leaf area and finally photosynthesis in cotton. in a...

Phenological responses to changing temperatures are known as "fingerprints of climate change," yet these reactions are highly species specific. To assess whether different plant characteristics are related to these species-specific responses in flowering phenology, we observed the first flowering day (FFD) of ten herbaceous species along two elevational gradients, representing temperature gradi...

Net photosynthetic assimilation rate (A), extractable activities of three photosynthetic enzymes, and the concentrations of six metabolites were determined for wheat (Tricum aestivum L.) leaves as leaf temperature was varied under photorespiring (350 microliters per liter CO(2) and 21% O(2)) and under nonphotorespiring conditions (800 microliters per liter CO(2) and 2% O(2)). The extractable ac...

The response of tomato plants (Solanum lycopersicum L. cv. Aromata) to continuous light (CL) in relation to photosynthesis, abscisic acid (ABA) and reactive oxygen species (ROS) was investigated to improve the understanding of the development and/or alleviation of CL-induced leaf injury in constant and diurnal temperature fluctuations with similar daily light integral and daily mean temperature...

Volatile organic compounds (VOCs) are expected to have an important role in plant adaptation to high temperatures. The impacts of increasing night-time temperature on daytime terpenoid emissions and related gene expression in silver birch (Betula pendula) and European aspen (Populus tremula) clones were studied. The plants were grown under five different night-time temperatures (6, 10, 14, 18, ...

the production of reactive oxygen species (ros) in plants under low temperature stress cause damage to plants. in order to evaluate of antioxidant responses of page mandarin young trees (two years old) on different rootstocks under low temperatures, an experiment was conducted in a factorial plan based on completely randomized design. treatment of temperatures were at seven levels include 9, 6,...