Smirnovia iranica, a native valuable woody species from Fabaceae, is an adaptable plant of central sandy areas of Iran. Changes in chlorophyll fluorescence and photosynthetic pigments characteristics were analyzed in the course of phenological stages including vegetative, flowering, seed ripening, and seed falling stages, respectively (VS, FS, SRS, and SFS). The results obtained from analysis o...

Substituted Benzoquinones, Photosystem II Acceptors Benzoquinones (BQ) substituted with alkyl or alkoxy groups 2,5-dimethoxy-3,6-dichloro-/>benzoquinone (DCDMQ), 2,3,5,6-tetramethoxy-/?-benzoquinone (TMQ) have been tested for their electron affinity and site of action in the photosynthetic electron transport chain in whole cells and chloroplasts. Both the substituted compounds were found to be ...

The pesticide PCP was shown to inhibit the Hill reaction in broken chloroplasts (I50 = 15 jam) and to quench chlorophyll fluorescence. Both effects require preillumination. In contrast to the common “phenol-type” inhibitors, neither inhibition of Hill reaction nor chlorophyll fluorescence quench were affected by pretreatment of chloroplast with trypsin instead o f preillumination. An inhibition...

Nitrogen is a major limiting factor for crop productivity. The relationship between photosynthesis and nitrogen nutrition has been widely studied. However, the molecular response of leaf photosynthesis to low nitrogen supply in crops is less clear. In this study, RNA sequencing technology (RNA-Seq) was used to investigate the gene expressions related to photosynthesis in maize in response to lo...

A novel fluorescence technique for monitoring the redox status of c-type cytochromes in Geobacter sulfurreducens was developed in order to evaluate the capacity of these extracytoplasmic cytochromes to store electrons during periods in which an external electron acceptor is not available. When intact cells in which the cytochromes were in a reduced state were excited at a wavelength of 350 nm, ...

Artificially mediated linear (methylviologen) and cyclic (phenazine methosulfate) electron transport induced zeaxanthin-dependent and independent (constitutive) nonphotochemical quenching in osmotically shocked chloroplasts of pea (Pisum sativum L. cv Oregon). Nonphotochemical quenching was quantitated as Stern-Volmer quenching (SV(N)) calculated as (F(m)/F'(m))-1 where F(m) is the fluorescence...

The effect of excess of cadmium (Cd) on chlorophyll fluorescence of barley seedlings was studied. The leaves were dark-adapted and then illuminated at 10 different light intensities within the range of 70–1600 μmol.m–2.s–1 photosynthetically active radiation (PAR). It was found that Cd decreases the chlorophyll fluorescence parameters in dark-adapted leaves: ground (Fo), maximal (Fm) and variab...

Pink Petuniahybrida (cv Hit Parade Rosa) corollas were found to contain photosynthetically active chloroplasts. The corolla chloroplasts were similar to those of green leaves in size and structure. The chlorophyll (Chl) content of Petunia corollas increased during early stages of flower development, reaching a maximum just before anthesis. Chloroplasts isolated from corollas at this stage, carr...

Tobacco (Nicotiana tabacum var Petit Havana) ndhB-inactivated mutants (ndhB-) obtained by plastid transformation (E.M. Horvath, S.O. Peter, T. Joët, D. Rumeau, L. Cournac, G.V. Horvath, T.A. Kavanagh, C. Schäfer, G. Peltier, P. MedgyesyHorvath [2000] Plant Physiol 123: 1337-1350) were used to study the role of the NADH-dehydrogenase complex (NDH) during photosynthesis and particularly the invol...