Reef corals typically contain a number of pigments, mostly due to their symbiotic relationship with photosynthetic dinoflagellates. These pigments usually vary in presence and concentration and influence the spectral characteristics of corals. We studied the variations in pigment composition among seven Caribbean shallow-water Scleractinian corals by means of High Performance Liquid Chromatogra...

A correlation between the amplitude of the electrochromic absorption changes measured at 480 nm and 520 nm and the size of the photosynthetic unit is found. Three tobacco mutants which differ with respect to their photosynthetic unit size exhibit decreased amplitudes of the electrochromic absorption changes which parallel the size of the photosynthetic units. Under these conditions the ATP-yiel...

The amount of light energy that is harvested and directed to the photosynthetic machinery is regulated in order to control the production of reactive oxygen species (ROS) in leaf tissues. ROS have important roles as signalling factors that instigate and mediate a range of cellular responses, suggesting that the mechanisms regulating light-harvesting and photosynthetic energy transduction also a...

Chlorophylis cl and c2 have been separted from total pigment extracts of the alg Pavlovagyras Butcher using a reversed-phae high-performance liquid chromatography system. Pigments were separated on a 5 micrometer Cl, column (25 centimeters x 4.6 millimeters) using a gadient ofmethanol-acetonitrile-water. Other photosynthetic pigments were also well resolved by the system used. The separation sy...

The para -nitro substituted diphenyl ether herbicides which cause rapid plant pigment photobleaching can be divided into two categories: 1. those that have a photosynthetic requirement for activity (e.g. oxyfluorfen) and 2. those that have no apparent metabolic requirement for activity (e.g. acifluorfen). A m odel is presented for the latter category, in which the diphenyl ether herbicide inter...

Phycobilins function as light-harvesting pigments in most cyanobacteria and red algae. Although green cyanobacteria of the genus Prochlorococcus express genes encoding enzymes that direct the synthesis of phycobilins, these pigments do not appear to play a role in light harvesting in Prochlorococcus. Now, it is shown that cyanophages infecting Prochlorococcus also contain genes for phycobilin-s...

Much of the life on earth depends on photosynthesis, a process in which electromagnetic solar energy is used to produce oxygen and carbohydrates from atmospheric CO2 and water. In plants and algae, the photosynthetic reactions are catalyzed by a system that includes several protein-pigment complexes embedded in the thylakoid membranes. These membranes consist of flattened vesicles that exist ei...

Chlorella vulgaris was grown using mixed sources of nitrogen (nitrate and nitrite). Starting from B3N as basal medium, nitrate substituted by nitrite keeping total constant over 7 conditions: 0, 20, 40, 50, 60, 80 100% NO2–. Growth rate, uptake, photosynthetic apparatus status pigment contents were monitored. Nitrite addition triggered a growth rate inhibition early introduction (20% NO2–, 81 m...