Cyclodextrins, a class of cyclic oligomeric compounds consisting of 6–8 units of D-glucose, alter the oxygen evolution of photosystem II (PSII) in barley thylakoids as well as chlorophyll a fluorescence induction, i.e., Fv/Fo and Fv/Fm where Fm is the maximal level of fluorescence when all PSII centres are closed, Fo is the minimal level of chlorophyll fluorescence when all PSII centres are ope...

Since chlorophyll fluorescence reflects the redox state of photosynthetic electron transport chain, monitoring of chlorophyll fluorescence has been successfully applied for the screening of photosynthesis-related genes. Here we report that the mutants having a defect in the regulation of photosystem stoichiometry could be identified through the simple comparison of the induction kinetics of chl...

The aim of this paper is to give a global insight into the behaviour of F0 and FM in a wide temperature range from -100 degreesC to 75 degreesC. We show that the F0 increases upon linear freezing, similarly to the widely published increase of the F0 upon linear heating. In contrast to this the FM decreases upon linear heating in the whole temperature range from -100 degreesC to 75 degreesC. A c...

Chlorophyll is a pyrrolic pigment with important optical properties, which is the reason it has been studied for many years. Recently, interest has been rising with respect to this molecule because of its outstanding physicochemical properties, particularly applicable to the design and development of luminescent materials, hybrid sensor systems, and photodynamic therapy devices for the treatmen...

Laser-induced fluorescence (LIF) spectra of intertidal microphytobenthos (MPB) communities were obtained in the laboratory with a 532 nm pulsed Nd:YAG laser. The laser-induced chlorophyll (chl) fluorescence emission spectra of MPB in mud and sand sediments were characterized by a band in the red region with a maximum at ca. 685 nm. Biomass accumulation on the surface of the mud due to cell migr...

The aim of this study was to assess the effect of UV-A (320 to 400 nm) and UV-B (280 to 320 nm) radiation on diel patterns of growth and metabolic activity of the marine picoplankter Nannochloris atomus using flow cytometry. N. atomus cells exposed to PAR (400 to 700 nm), PAR+UV-A and PAR+UV-A+UV-B showed clear diel patterns in cell size, chlorophyll fluorescence and metabolic activity, the lat...

In this work we demonstrate enhancement of the fluorescence collection efficiency for chlorophyll-containing photosynthetic complexes deposited on SiO2 spherical nanoparticles. Microscopic images of fluorescence emission reveal ring-like emission patterns associated with chlorophyll-containing complexes coupled to electromagnetic modes within the silica nanoparticles. The interaction leaves no ...

Barley leaves grown under a natural light/dark regime have a chlorophyll content of 1300 [ig/g fresh weight and a chlorophyll a /b ratio of 2 .5 -3 . When the plants are grown under cycles of 2 min light/118 min dark, the respective values are 50 and 5 — 9. With chloroplasts with low chlo­ rophyll b content variable fluorescence is depressed by about 30% by MgCl2; with those of high chlorophyll...