Flash-Induced Delayed Light Emission Patterns of Red Kidney Bean Leaves: Evidence of a New Component Dependent upon Tissue Integrity.

Studies of flash-induced delayed light emission profiles of dark-adapted intact plant tissues revealed a previously unreported component of plant luminescence. Only partially evident in intact chloroplasts and totally absent in broken chloroplasts, this peak may reflect the interaction of one or more light-activated enzyme systems with photosynthetic electron transport.

Chlorophyll fluorescence characteristics associated with hydration level in pea cotyledons.

In order to study the effects of desiccation on a photosynthetic system, light harvesting and light-induced electron transport processes were examined in pea cotyledons at various moisture levels, using in vivo fluorescence excitation spectra and fluorescence induction kinetics. Water sorption isotherms yielded thermodynamic data that suggested very strong water binding between 4 to 11% water, intermediate sorption between water contents of 13 to 22%, and very weak binding at moisture contents between 24 to 32%. The fluorescence properties of the tissue changed with the moisture contents, and these changes correlated generally with the three regions of water binding.

Phytoluminographic detection of dynamic variations in leaf gaseous conductivity.

Gas exchange and plant luminescence (delayed light emission) of a single red kidney bean leaf undergoing synchronous oscillations in gas exchange were recorded and analyzed. Introduction of 1.1 microliter per liter SO(2) during these oscillations produced increases in plant luminescence that, when averaged over a portion of the leaf, oscillated in phase with the gas exchange oscillations.

Gas Exchange and Phytoluminography of Single Red Kidney Bean Leaves during Periods of Induced Stomatal Oscillations: A Demonstration of an Integrated, Spatially Resolving Physiometric Technique.

This report examines the capabilities of a new approach to the study of gas exchange and electron transport properties of single, intact leaves. The method combines conventional aspects of analysis with an image intensification system that records the spatial distribution of delayed light emission (DLE) over single leaf surfaces. The combined system was used to investigate physiological perturbations induced by exposure of single leaves of Phaseolus vulgaris cv ;California Light Red' to a combination of SO(2) (0.

Delayed light imaging for the early detection of plant stress.

Image-intensified photographs of delayed light emission (DLE) from soybean leaves exposed to sulfur dioxide showed evidence of the stress that developed during the exposure period. A comparison of DLE images taken during the fumigation with a conventional photograph taken 5 days later showed a clear correspondence between leaf areas that had the most diminished DLE intensity and those that showed the greatest visible injury. These results suggest that DLE imagery will be a useful tool in the investigation of the spatial distribution and temporal development of plant stress.