The chemical structural differences distinguishing chlorophylls in oxygenic photosynthetic organisms are either formyl substitution (chlorophyll b, d, and f) or the degree of unsaturation (8-vinyl chlorophyll a and b) of a side chain of the macrocycle compared with chlorophyll a. We conducted an investigation of the conversion of vinyl to formyl groups among naturally occurring chlorophylls. We...

The chlorophyll a:b ratio was shifted in Chlorella vannielii by varying the illuminance under which the cells were cultured-the ratio increased from 2.9, 3.0, 4.0, and 4.8 to 6.2, respectively, at 100, 300, 900, 2,700 and 6,000 foot candles. The 6,000-foot candle cells retained an optimal growth rate at the chlorophyll a:b ratio of 6.2 which was the upper limit of normal growth. Comparisons wer...

There is now evidence that aerobic anoxygenic phototrophic (AAP) bacteria are widespread across aquatic systems, yet the factors that determine their abundance and activity are still not well understood, particularly in freshwaters. Here we describe the patterns in AAP abundance, cell size and pigment content across wide environmental gradients in 43 temperate and boreal lakes of Québec. AAP ba...

In arid and semi-arid areas of the world, excessive mineral aerosol carried by air parcels is a common climatic incident with well-known environmental side effects. In this study, the role of sand-dust accumulation was investigated on various aspects of photosynthetic yield of Plantago lanceolata including chlorophyll (Chl) a, b, effective quantum yield of PSII photosystem (ФPSII), maximal quan...

Chlorophyll degradation is an aspect of leaf senescence, which is an active process to salvage nutrients from old tissues. non-yellow coloring1 (nyc1) is a rice (Oryza sativa) stay-green mutant in which chlorophyll degradation during senescence is impaired. Pigment analysis revealed that degradation of not only chlorophylls but also light-harvesting complex II (LHCII)-bound carotenoids was repr...

in order to investigate the effect of mycorrhizal fungi and phosphorus fertilizer on concentration of leaf nutrients and photosynthetic pigments of bean (phaseolus vulgaris l.) in condition of irrigation with saline water, an experiment was conducted based on completely randomized design with three replications in greenhouse of bahonar university of kerman, iran during 2010. the studied factors...

Growth, development and plants productivity are usually affected by photosynthetic pigments activity. Magnetic fields are known to induce biochemical changes and could be used as a stimulator for growth related reactions including affecting photosynthetic pigments. The impact of magnetic field strengths on chlorophyll and carotenoids were investigated in this study through the use of date palm ...

Nickel and cadmium are heavy metals with some hazards for plant metabolism. The impacts of nickel chloride (0, 400 and 800 μM) in the presence of vitamin B complex (0, 30 and 60 ml from pharmacy commercial stock) and the impacts of cadmium chloride (0, 100, 200, 300, 400, 500 and 600 μl from 100 µM stock) in pot and cadmium nitrate (0, 100, 200, 400, 800, 1600 and 3200 μl from 100 µM stock) in ...