Several plant species reveal the tolerance to acute desiccation stress (eg. Antarctic lichens [3,4,5]). During rehydration process they can take water directly from gaseous phase in [2]. These facts focus the attention on the response of the isolated cell organellae to extreme environmental conditions. Photosynthetic membranes were selected by their importance for plant photosynthetic activity....

The global decline of reef-building corals is due in part to the loss of algal symbionts, or "bleaching," during the increasingly frequent periods of high seawater temperatures. During bleaching, endosymbiotic dinoflagellate algae (Symbiodinium spp.) either are lost from the animal tissue or lose their photosynthetic pigments, resulting in host mortality if the Symbiodinium populations fail to ...

Intermolecular electronic coupling dictates the optical properties of molecular aggregate systems. Of particular interest are photosynthetic pigment-protein complexes that absorb sunlight then efficiently direct energy toward the photosynthetic reaction center. Two-dimensional (2D) ultrafast spectroscopy has been used widely in the infrared (IR) and increasingly in the visible to probe excitoni...

The history of research on photosynthetic reaction centers is outlined, starting with the implication of their existence through the discovery of the photosynthetic unit, as reported by R. Emerson and W. Arnold in 1932, and culminating in the crystallization and X-ray analysis of the anoxygenic bacterial reaction centers, reported by J. Deisenhofer, H. Michel, and coworkers, over the period 198...

The influence of exogenous application of glycine betaine (GlyBet) was examined on photosynthetic pigments and ions concentration of safflower under salinity stress conditions. The experiment was performed in a randomized complete block design arranged as a factorial with three replications. Salinity treatments (0, 50, 100, and 150 mM) were applied using sodium chloride (NaCl). GlyBet (0, 10, 3...

Measurement of vegetation photosynthetic activity from space has been an objective for the development of new techniques. Among the different existing techniques, passive fluorescence measurements, specific reflectance indices such as the PRI (Photochemical Reflectance Index), and derivative of high spectral resolution reflectance in the red-edge (680-750 nm) are the three methods than can be u...

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 ...