From the absorption spectra and the excitation spectra of chlorophyll a fluorescence measured (4-77 °K) at different wavelengths (685-760 nm) and their comparison with the emission spectra published elsewhere 23, we confirm that both the Pigment Systems (I and II) contain chlorophyll b, chlorophyll a 670 and chlorophyll a 678. But System II is relatively enriched in chlorophyll b and System I i...

To understand the physiological mechanism by which soybean (cultivar: Glycine max L. Merr. cv.JH13) regulates its growth in response to drought under elevated CO 2 concentration, a pot experiment with two levels of CO 2 (350 vs. 700 μmol·mol) and two levels of water (well irrigated vs. drought) was conducted. Plant relative growth rate (RGR), water potential (WP), photosynthetic pigment (chloro...

to assess nickel-induced toxicity in plants, zea mays seeds were germinated and cultured on nutrient solution with nickel concentrations of 0, 50, 100 and 200 μm for a period of two weeks. its effects on the growth, hill reaction and photosynthetic pigments content were then investigated. the fresh and dry weight of leaves and roots increased in 50 μm nickel, but decreased in 100 and 200 μm. th...

The potential of lecithin BLM with chlorophyll a and with and without carotene has been measured. The BLM containing both chlorophyll a and carotene have shown the highest value of the photopotential. Stronger fatigue effect during light puis excitation has been found on BLM with pigments than with isolated chlorophyll a-protein complex extracted from blue green alga.

This study uses derivative spectroscopy to assess qualitative and quantitative information regarding seafloor types that can be extracted from hyperspectral remote sensing reflectance signals. Carbonate sediments with variable concentrations of microbial pigments were used as a model system. Reflectance signals measured directly over sediment bottoms were compared with remotely sensed data from...

Epidemiological and experimental evidence indicates a strong relationship between diet and cancer. The purpose of this study was to examine the potential of chlorophyllin (CHL), a food-grade derivative of the ubiquitous green plant pigment chlorophyll, to inhibit experimental carcinogenesis. We report that CHL is a potent, dose-responsive inhibitor of aflatoxin B1 DNA adduction and hepatocarcin...

The effects of a widely used herbicide, atrazine, on the freshwater cyanobacterium Synechococcus elongatus were studied. The cyanobacteria were exposed to varying concentrations of atrazine (0.025, 0.05, 0.1, 0.25, and 0.75 microM) for 96 h. Different parameters such as growth, autofluorescence of chlorophyll a, pigment content, volume, and internal granularity of the cells were determined dail...

The nitrogen-rich phycobiliproteins are efficient light-harvesting pigments of cryptophytes, cyanobacteria, and rhodophytes. Whereas it is well established that certain cyanobacteria mobilize their phycobiliproteins in response to nitrogen deprivation, the effect of nitrogen stress on cryptophyte physiology has been studied only rarely. We compared the effects of nitrogen and phosphorus depleti...

The yellow-green leaf mutant has a non-lethal chlorophyll-deficient mutation that can be exploited in photosynthesis and plant development research. A novel yellow-green mutant derived from Triticum durum var. Cappelli displays a yellow-green leaf color from the seedling stage to the mature stage. Examination of the mutant chloroplasts with transmission electron microscopy revealed that the sha...

Abiotic stress can alter key physiological constituents and functions in green plants. Improving the capacity to monitor this response in a non-destructive manner is of considerable interest, as it would offer a direct means of initiating timely corrective action. Given the vital role that plant pigments play in the photosynthetic process and general plant physiological condition, their accurat...