Simultaneous gas exchange and fluorescence measurements indicate differences in the response of sunflower, bean and maize to water stress.

Gas exchange and fluorescence measurements of attached leaves of water stressed bean, sunflower and maize plants were carried out at two light intensities (250 μmol quanta m(-2)s(-1) and 850 μmol quanta m(-2)s(-1)). Besides the restriction of transpiration and CO2 uptake, the dissipation of excess light energy was clearly reflected in the light and dark reactions of photosynthesis under stress conditions. Bean and maize plants preferentially use non-photochemical quenching for light energy dissipation.

Light Energy Dissipation under Water Stress Conditions: Contribution of Reassimilation and Evidence for Additional Processes.

Using (14)CO(2) gas exchange and metabolite analyses, stomatal as well as total internal CO(2) uptake and evolution were estimated. Pulse modulated fluorescence was measured during induction and steady state of photosynthesis. Leaf water potential of Digitalis lanata EHRH.

The efficiency of water use in water stressed plants is increased due to ABA induced stomatal closure.

Gas exchange and abscisic acid content of Digitalis lanata EHRH. have been examined at different levels of plant water stress. Net photosynthesis, transpiration and conductance of attached leaves declined rapidly at first, then more slowly following the withholding of irrigation.

Fluorescence Quenching and Gas Exchange in a Water Stressed C(3) Plant, Digitalis lanata.

A leaf cuvette has been adapted for use with a pulse-modulation fluorometer and an open gas exchange system. Leaf water potential (psi) was decreased by withholding watering from Digitalis lanata EHRH. plants.

Separation of fatty acids or methyl esters including positional and geometric isomers by alumina argentation thin-layer chromatography.

This paper describes novel and rapid thin-layer chromatography procedures for the analysis of fatty acids and methyl esters using silver-impregnated alumina sheets. These techniques are known in most laboratories, and the equipment is readily available. The fatty acid method allows a separation of petroselinic (C18:1 delta 6c), oleic (C18:1 delta 9c), elaidic (C18:1 delta 9t), erucic (C22:1 delta 13c), and brassidic acids (C22:1 delta 13t), and the methyl ester method gives an excellent resolution with respect to the number, configuration, and position of the unsaturated centers.