Herbicidal Action of Monuron, Light, Oxygen, Singlet Oxygen, Plant Pigments Monuron treatment of detached flax cotyledons caused a rapid inhibition of C 02 fixation in darkness and light. Chlorophyll breakdown was promoted by increased light intensity. Ethane generation, an indicator of membrane damage, increased as the chlorophyll level decreased. The carotene pigments were destroyed more rapi...

We describe spectral reflectance measurements of snow containing the snow alga Chlamydomonas nivalis and a model to retrieve snow algal concentrations from airborne imaging spectrometer data. Because cells of C. nivalis absorb at specific wavelengths in regions indicative of carotenoids (astaxanthin esters, lutein, beta-carotene) and chlorophylls a and b, the spectral signature of snow containi...

Many plant growth regulators (PGRs) are known to alleviate the negative effects of drought stress in plants. However, limited research has been conducted to investigate the potential benefits of exogenous application of PGRs in wheat plants grown under drought stress. In the present study, effects of salicylic acid (SA) and chlormequat chloride (CCC) on drought-stress induced changes in morpho-...

Characteristics and quantum efficiencies of photocurrents at monolayer, mixed monolayers, and multilayers of chlorophyll a deposited on semiconducting SnOz electrodes and/or metal electrodes were surveyed. The quantum efficiency of photocurrent depends on the surface concentration of chlorophyll a as well as the thickness of layers. The photocurrent behavior of chlorophyll a multilayers is comp...

The functionalizing of staple and economic foods, which means adding health-promoting substances, has been visualized as a solution to reduce the concerning increase in diet-related diseases caused by bad-eating patterns. Microalgae represent an innovative way solve this problem. Arthrospira platensis, microalgae nutritionally rich bioactive compounds, used develop hard wheat pasta (semolina) i...

We have probed the absorption changes due to an externally applied electric field (Stark effect) of Photosystem I (PSI) core complexes from the cyanobacteria Synechocystis sp. PCC 6803, Synechococcus elongatus and Spirulina platensis. The results reveal that the so-called C719 chlorophylls in S. elongatus and S. platensis are characterized by very large polarizability differences between the gr...

Experiments were conducted on Nicotiana tabacum, L. to study the relation in the grana among chlorophylls, carotenoids, and proteins. The effect of iron chlorosis on protein and pigment synthesis was studied at different stages of chlorosis using glycine-U-C(14). Pigments were separated by thin layer chromatography.Chlorophyll a, chlorophyll b, carotenoid, and protein contents of chloroplasts f...

Cytochrome b(6)f complexes contain a molecule of chlorophyll a (Chla), which, in Chlamydomonas reinhardtii, can be exchanged for extraneous chlorophyll during protracted incubation of the purified complex in detergent solution. The specificity of the site and its location in the complex have been studied by photochemical coupling and circular dichroism spectroscopy. Following substitution of th...

1. Aqueous extracts of spinach and Aspidistra leaves yield highly opalescent preparations which are not in true solution. Such extracts differ markedly from colloidal chlorophyll in their spectrum and fluorescence. The differences between the green leaf pigment and chlorophyll in organic solvents are shown to be due to combination of chlorophyll with protein in the leaf. 2. The effect of some a...

Cutting-derived Salix dasyclados Wimm. were grown on soil containing high amounts (2 kg m in year 1 + 1 kg m in year 2) of dust from filters of a cement plant. The pH of the treated soil was increased from 6.5 (control) to 7.6. Soluble sugars, starch, and chlorophylls in leaves of spring flush shoots were analysed during the vegetative growth of the second year of treatment. The lower hexose co...