Over-excitation of photosynthetic apparatus causing photoinhibition is counteracted by non-photochemical quenching (NPQ) of chlorophyll fluorescence, dissipating excess absorbed energy into heat. The PsbS protein plays a key role in this process, thus making the PsbS-less npq4 mutant unable to carry out qE, the major and most rapid component of NPQ. It was proposed that npq4 does perform qE-typ...

Incorporation of membrane proteins into reconstituted lipid membranes is a common approach for studying their structure and function relationship in native-like environment. In this work, we investigated fluorescence properties liposome-reconstituted major light-harvesting complexes plants (LHCII). By utilizing liposome labelling with the fluorescent dye molecules single-molecule microscopy tec...

ABSTRACT The objective was to study the chlorophyll ‘a’ fluorescence and photochemical quenching from ‘Tahiti’ acid lime grafted in new citrus genotypes under irrigation with three types of water during prefloration phase first year cultivation, purposing verify if are indicatives beginning ionic stress. An experiment set up salinity levels (0.14, 2.40 4.80 dS m-1), 13 rootstock, corresponding ...

Photochemical interpretations of slow (opto-electronic) phenomena in CdS crystals are investigated theoretically and experimentally. It is seen that the presence of Ni impurity atoms has a major influence on some of these slow phenomena. Consequently, impurity atoms must be included in the considerations if a model for photochemical bulk reactions is to be developed. A non-photochemical interpr...

Z. Naturforsch. 44b, 1585 — 1588 (1989); received February 2/July 27, 1989 Photochemical Reactions, Primary Aromatic Amines, Chloromethanes Interactions were studied of aniline, 4-methoxyaniline and 4-ethoxyaniline with tetrachloromethane, chloroform and dichloromethane in their ground and first excited singlet states. Stability constants of the complexes of these amines with the chloromethanes...

In diatoms, the non-photochemical fluorescence quenching (NPQ) regulates photosynthesis during light fluctuations. NPQ is associated with an enzymatic xanthophyll cycle (XC) which is controlled by the light-driven transthylakoid proton gradient (delta pH). In this report, special illumination conditions and chemicals were used to perturb the kinetics of the delta pH build-up, of the XC and of N...

Drought in heavy metal polluted arid and semiarid regions severely inhibits the plant growth phytoremediation potential by affecting photosynthesis, antioxidant defense mechanism, other biochemical processes. In present study, we explored role of growth-promoting bacteria (PGPB) on Zea mays efficiency Chromium (Cr) contaminated soils under drought stress assessing tolerance, photosynthetic gas ...

Cyclic electron flow (CEF) around PSI regulates acceptor-side limitations and has multiple functions in the green alga, Chlamydomonas reinhardtii. Here we draw on recent and historic literature and concentrate on its role in Photosystem I (PSI) photoprotection, outlining causes and consequences of damage to PSI and CEF's role as an avoidance mechanism. We outline two functions of CEF in PSI pho...

In the present work basic aspects of the bimolecular electron transfer processes have been studied by photochemical means and the heterogeneous electrochemical electron transfer processes have been applied in corrosion research and electroanalysis. Photoinduced electron transfer (ET) reactions were studied from the fluorescence quenching experiments using coumarins and quinones as the fluoropho...