Strong excitonic interactions are a key design strategy in photosynthetic light harvesting, expanding the spectral cross-section for light absorption and creating considerably faster and more robust excitation energy transfer. These molecular excitons are a direct result of exceptionally densely packed pigments in photosynthetic proteins. The main light-harvesting complexes of diatoms, known as...

The apoprotein of the major light harvesting pigment-protein complex from the diatom Phaeodactylum tricornutum (UTEX 646) is composed of two similar polypeptides of 17.5 and 18.0 kilodaltons (kD). The in vivo synthesis of these polypeptides is inhibited by the 80s protein synthesis inhibitor cycloheximide, but not by the 70s ribosome inhibitor chloramphenicol. When total poly(A)(+) RNA was used...

The effects of UV-B radiation on the amount of chlorophyll a, b, carotenoids, flavonoids, anthocyanins, and polyphenols of three soybean cultivars was studied. After germination in the incubator, plants were put in pots of soil and during 3 weeks and irrigated with Hoagland solution every day. After 3 weeks, plants were exposed to UV-B for 20 min every day for a week. In each cultivar, UV-B red...

To determine the effect of growth under elevated CO(2) partial pressures (pCO(2)) on photosynthetic electron transport and photoprotective energy dissipation, we examined light-saturated net photosynthetic CO(2) assimilation (A(sat)), the capacity for photosynthetic O(2) evolution, chlorophyll fluorescence emission and the pigment composition of upper-canopy loblolly pine needles in the eighth ...

We present a study on the evolution of the Fenna-Matthews-Olson bacterial photosynthetic pigment-protein complex. This protein complex functions as an antenna. It transports absorbed photons-excitons-to a reaction center where photosynthetic reactions initiate. The efficiency of exciton transport is therefore fundamental for the photosynthetic bacterium's survival. We have reconstructed an ance...

Photosynthetic organisms harvest sunlight with near unity quantum efficiency. The complexity of the electronic structure and energy transfer pathways within networks of photosynthetic pigment-protein complexes often obscures the mechanisms behind the efficient light-absorption-to-charge conversion process. Recent experiments, particularly using two-dimensional spectroscopy, have detected long-l...

Recent experiments suggest that electronic energy transfer in photosynthetic pigment-protein complexes involves long-lived quantum coherence among electronic excitations of pigments. [Engel et al., Nature, 2007, 446, 782-786.] The observation has led to the suggestion that quantum coherence might play a significant role in achieving the remarkable efficiency of photosynthetic light harvesting. ...

When bleached, aerobically grown cells of Rhodopseudornonas spheroides are transferred to semi-aerobic conditions to induce bacteriochlorophyll synthesis, a new fluorescence band, with a maximum at 790 nm, is observed in addition to the 885 nm emission maximum normally seen in pigmented cells. The 790 nm fluorescence may be due to bacteriochlorophyll which has not been bound into the chromatoph...