Fluorescence, Delayed Fluorescence, Photosystem I The changes in the fluorescence and delayed fluorescence intensity of spinach leaf as affected by temperature were studied. It was observed that the delayed fluorescence showed a maximum at about 45 °C whereas the fluorescence maximum was at about 55 °C. An examination of the emission spectra of delayed fluorescence at different temperatures sho...

The light-harvesting complexes of photosystem I and II (Lhcas and Lhcbs) of plants display a high structural homology and similar pigment content and organization. Yet, the spectroscopic properties of these complexes, and accordingly their functionality, differ substantially. This difference is primarily due to the charge-transfer (CT) character of a chlorophyll dimer in all Lhcas, which mixes ...

The proteins encoded by psaA and psaB form a heterodimer, an essential compound of photosystem; while the protein encoded by psbC binds with chlorophyll a in photosystem II, serving as antennae in photosystem. Here we report that a heterocyclic brominated flame retardant, tris(2,3-dibromopropyl) isocyanurate (TBC), inhibited the expression of psaA and psbC, then leads to the decrease of Nannoch...

The effects of disalicylidenepropanediamine (DSPD) and disulfo-disalicylidenepropanediamine (sulfo-DSPD) on the photosynthetic electron transport of isolated chloroplasts have been reexamined.Our data suggest that DSPD, but not sulfo-DSPD, is an effective inhibitor of electron transport between photosystem II and photosystem I before or at plastocyanin. Furthermore, both DSPD and sulfo-DSPD blo...

Pseudomonas syringae pv. tabaci (Pst) is a hemibiotrophic bacterial pathogen responsible for tobacco wildfire disease. Although considerable research has been conducted on the tobacco plant's tolerance to Pst, the role of light in the responses of the photosystems to Pst infection is poorly understood. This study aimed to elucidate the underlying mechanisms of the reduced photosystem damage in ...

Bundle sheath and mesophyll chloroplasts from Zea mays showed comparable rates of O(2) evolution, which amounted to about half of the rate observed in spinach (Spinacia oleracea) chloroplasts.Ratios of 4.5, 4.6, and 6.2 Mn(2+) atoms per 400 chlorophylls were observed in mesophyll, bundle sheath, and spinach chloroplasts, respectively. These ratios roughly correspond to the observed O(2) evoluti...

The cyanobacterial cytochrome b(6)f complex is central for the coordination of photosynthetic and respiratory electron transport and also for the balance between linear and cyclic electron transport. The development of a purification strategy for a highly active dimeric b(6)f complex from the thermophilic cyanobacterium Thermosynechococcus elongatus BP-1 enabled characterization of the structur...

Overview of the rich and diverse contributions quantum chemistry to understanding structure function biological archetypes for solar fuel research, photosystem II hydrogenases.

G u d r u n Wälzlein, Ach im E . G a u , and El f r iede K. Pistorius Universität Bielefeld, Fakultät für Biologie, Lehrstuhl Zellphysiologie, D-4800 Bielefeld 1, Bundesrepublik Deutschland Z. Naturforsch. 43c, 545-553 (1988); received January 25, 1988 L-Amino Acid Oxidase, Flavoprotein, Photosystem II, Cyanobacteria, Anacystis nidulans The absorption spectrum of the previously purified L-amino...

The input of solar energy into photosynthesis, and thence into the biosphere, occurs via chlorophyll-containing proteins known as reaction centres. There are two kinds of reaction centre in oxygenic photosynthesis: photosystem I (PSI) and photosystem II (PSII). The PSII reaction centre, alias the oxygen-evolving enzyme, the water-oxidizing complex or the water-plastoquinone photo-oxidoreductase...