Photosynthetic rates, chlorophyll content, and activities of several photosynthetic enzymes were determined per cell, per unit DNA, and per unit leaf area in five ploidal levels of the C(4) dicot Atriplex confertifolia. Volumes of bundle sheath and mesophyll protoplasts were measured in enzymatic digestions of leaf tissue. Photosynthetic rates per cell, contents of DNA per cell, and activities ...

Rangelands play a critical role in the global carbon cycle. However, the eco-physiological mechanisms associated with the effects of grazing on leaf photosynthesis and soil respiration remain poorly understood. To examine the impacts of grazing on leaf photosynthesis and soil respiration, we measured the photosynthetic parameters of the dominant species (Trifolium repens) and the soil respirati...

Biochemical models of leaf photosynthesis, based on the seminal work of Farquhar et al. (1980), have been widely used to compare photosynthetic performance among plant species and to analyse photosynthetic acclimation to high CO2 concentrations or growth irradiance. Such functional models may also be coupled to radiation transfer models, which are structural models, to simulate photosynthesis a...

Charge transfer through biological macromolecules is essential for many biological processes such as, for instance, photosynthesis and respiration. Protons or electrons are transferred between titratable residues or redox-active cofactors, respectively. Transfer rates between these sites depend on the current charge configuration of neighboring sites. Here, we formulate the kinetics of charge-t...

One-year-old jack pine (Pinus banksiana Lamb.) and current-year white birch (Betula papyrifera Marsh.) seedlings were grown in ambient (360 ppm) or twice ambient (720 ppm) atmospheric CO2 concentration ([CO2]) and at three soil temperatures (Tsoil = 7, 17 and 27 degrees C initially, increased to 10, 20 and 30 degrees C two months later, respectively) in a greenhouse for 4 months. In situ foliar...

Two soybean (Glycine max L. Merrill) cultivars, Shin-Tanbakuro and Midori, were grown under mild water stress conditions for 11 days at the vegetative growth stage in order to examine the effect of drought stress on plant biomass production, photosynthetic gas exchange, chlorophyll fluorescence and photoassimilate translocation along with changes in carbohydrates and nitrogen. Relative growth r...

A plantation trial of six selected clones of Dalbergia sissoo Roxb. laid out in randomized block design at four sites in northern India during July, 1996 was evaluated for growth, physiological and biochemical parameters. Genotype-site interactions were significant for collar diameter increment, photosynthetic rate, transpiration rate, stomatal conductance, photosynthetic pigments, total solubl...

This paper aimed to evaluate the effects of different concentrations of cadmium on growth rates, photosynthetic pigments, photosynthetic performance, biochemical parameters and structure of chloroplasts in G. domingensis. To accomplish this, apical segments of G. domingensis were cultivated with different concentrations of cadmium, ranging from 100 to 300 μM, over a period of 16 days, and were ...