Chloroplasts isolated from tall fescue, Festuca arundinacea Schreb., showed high rates of electron transport, comparable to rates observed for spinach chloroplasts.Chloroplasts were well coupled and rates of electron transport from water to methyl viologen (photosystem II and I) were increased two to five times when ADP and inorganic phosphate or methylamine (uncoupler) were added to the reacti...

Membranes enriched in photosystem II were isolated from spinach and further solubilised using n-octyl beta-D-glucopyranoside (OctGlc) and n-dodecyl beta-D-maltoside (DodGlc2). The OctGlc preparation had high rates of oxygen evolution and when subjected to size-exclusion HPLC and sucrose density gradient centrifugation, in the presence of DodGlc2, separated into dimeric (430 kDa), monomeric (236...

IV INTRODUCTION 66 A. Structure of the Photosynthetic Apparatus of Green Plants 66 B. General Scheme of Electron Transport in the Photosynthesis of Higher Plants 67 C. The Main Types of ESR Signals Observed in Photosynthetic Systems 68 D. The Main Problems Solvable by the ESR Technique 70 PARMAGNETIC CENTERS AT EARLY STAGES OF LIGHT-INDUCED CHARGE SEPARATION IN PHOTOSYSTEM I '. 70 A. Chlorophyl...

Using a cotransformation system to identify chloroplast transformants in Chlamydomonas reinhardtii, we converted histidine-195 of the photosystem II reaction center D1 protein to a tyrosine residue. The mutants were characterized by a reduced quantum efficiency for photosynthetic oxygen evolution, which varied in a pH-dependent manner, a reduced capacity to oxidize artificial donors to photosys...

Light dependence and kinetics of reversible phosphorylation of the D1 reaction center protein of Photosystem II was studied in pumpkin leaves. At growth light, maximal phosphorylation of D1 was observed after illumination of 1 h, with higher phosphorylation rates at stronger irradiances. 70-85% of D1 became phosphorylated, corresponding to the proportion of the protein in appressed thylakoid me...

Experimental work on the control of photosystem II in the photosynthetic apparatus of higher plants, mosses and lichens is reviewed on a background of current literature. Transmembrane proton transport during photoassimilatory and photorespiratory electron flows is considered insufficient for producing the intrathylakoid acidification necessary for control of photosystem II activity under exces...

We present a systematic study of the effect of antenna size on energy transfer and trapping in photosystem II. Time-resolved fluorescence experiments have been used to probe a range of particles isolated from both higher plants and the cyanobacterium Synechocystis 6803. The isolated reaction center dynamics are represented by a quasi-phenomenological model that fits the extensive time-resolved ...

Dark-grown Chlamydomonas reinhardtii cultures that were illuminated at low fluence rates before exposure to high-light conditions exhibited a faster rate of recovery from photoinhibition than did dark-grown cells that were directly exposed to photoinhibitory conditions. This pretreatment has been shown to induce the expression of several nuclear heat shock protein 70 (HSP70) genes, including HS...

The oxygen-evolving photosystem II particles prepared from spinach chloroplasts with brief sonication and Triton X-100 treatment were subjected to butanol/water phase partitioning. Three peripheral proteins of photosystem II having relative molecular masses of 33,000, 24,000, and 18,000 daltons and a part of the manganese atoms associated with photosystem II were partitioned into the aqueous ph...

the effects of water deficit on grain yield, yield components and the physiological char-acteristics of barley (hordeum vulgare l.) varieties were studied in a split plot design dur-ing the 1999-2000 growing season in karaj, iran. five irrigation levels [0, 25, 50, 75, and 100% crop water requirements (cwr)] and six barley varieties karoon kavir , rei-hani(drought tolerant), torkman , c-74-9 (i...