Introduction The rate and extent of leaf thickness and area Leaves which develop at elevated CO2 concentrations are development are important determinants of whole often thicker than those on ambient 2 plants. In a plant photosynthetic capacity. The interactive effects study of four Populus clones, Radoglou and Jarvis (1990) of photon flux density (PFD), nitrogen supply and CO 2 found increases...

To find a way to promote the rate of carbon flux and further improve the photosynthetic rate in rice, two CO2-transporting and fixing relevant genes, Ictb and FBP/Sbpase, which were derived from cyanobacteria with the 35SCaMV promotor in the respective constructs, were transformed into rice. Three homologous transgenic groups with Ictb, FBP/Sbpase and the two genes combined were constructed in ...

Background: Medical plants production, including borago, is for maximum productivity from their effective ingredients’. Flowers, leaves and seed oil are medical parts of borago. Unfortunately, because of little breeding and domestication programs in medical plants, including borago, their establishments are usually slow. One of the effective techniques for solving this problem is seed priming. ...

Rooted cuttings from three aspen (Populus tremuloides Michx.) clones (216, 271 and 259, classified as high, intermediate and low in O(3) tolerance, respectively) were exposed to either diurnal O(3) profiles simulating those of Michigan's Lower Peninsula (episodic treatments), or diurnal square-wave O(3) treatments in open-top chambers in northern Michigan, USA. Ozone was dispensed in chambers v...

The 11 plastid ndh genes have hovered frequently on the edge of dispensability, being absent in the plastid DNA of many algae and certain higher plants. We have compared the photosynthetic activity of tobacco (Nicotiana tabacum, cv. Petit Havana) with five transgenic lines (ΔndhF, pr-ΔndhF, T181D, T181A, and ndhF FC) and found that photosynthetic performance is impaired in transgenic ndhF-defec...

Variability of leaf traits related to photosynthesis was assessed in seedlings from 14 tree species growing in the tropical rain forest of French Guiana. Leaf photosynthetic capacity (maximum rate of carboxylation and maximum rate of electron transport) was estimated by fitting a biochemical model of photosynthesis to response curves of net CO2 assimilation rate versus intercellular CO2 mole fr...

Photosynthesis-irradiance (P-I) characteristics of periphyton (microphytobenthos) have been considered primarily for entire assemblages. How P-I responses vary with mat thickness and with community composition has not been considered in detail. We used a combined approach of modeling, microscale determinations of photosynthetic rate and light attenuation, and whole-assemblage O2 flux measuremen...

The physiological basis for the advantage of alternate partial root-zone irrigation (PRI) over common deficit irrigation (DI) in improving crop water use efficiency (WUE) remains largely elusive. Here leaf gas exchange characteristics and photosynthetic CO(2)-response and light-response curves for maize (Zea mays L.) leaves exposed to PRI and DI were analysed under three N-fertilization rates, ...

Effects of irradiance on photosynthetic characteristics were examined in senescent leaves of rice (Oryza sativa L.). Two irradiance treatments (100 and 20% natural sunlight) were imposed after the full expansion of the 13th leaf through senescence. The photosynthetic rate was measured as a function of intercellular CO(2) pressure with a gas-exchange system. The amounts of cytochrome f, coupling...

loides Michx.) clones (216, 271 and 259, classified as high, intermediate and low in O3 tolerance, respectively) were exposed to either diurnal O3 profiles simulating those of Michigan’s Lower Peninsula (episodic treatments), or diurnal square-wave O3 treatments in open-top chambers in northern Michigan, USA. Ozone was dispensed in chambers ventilated with charcoal-filtered (CF) air. In additio...