The companion cells (CCs) and/or phloem parenchyma cells (PCs) in foliar minor veins of some species exhibit invaginations that are amplified when plants develop in high light (HL) compared to low light (LL). Leaves of plants that develop under HL also exhibit greater maximal rates of photosynthesis compared to those that develop under LL, suggesting that the increased membrane area of CCs and ...

Adult rainbow trout were pre-exposed to a sublethal concentration of waterborne cadmium (Cd, 26.7 nmol/l) or waterborne zinc (Zn, 2294 nmol/l) for 30 days to induce acclimation. A single dose of radiolabeled Cd (64.4 nmol/kg) or Zn (183.8 nmol/kg) was injected into the vascular system of non-acclimated and Cd- or Zn-acclimated trout through indwelling arterial catheters. Subsequently, repetitiv...

Barley leaves grown under a natural light/dark regime have a chlorophyll content of 1300 [ig/g fresh weight and a chlorophyll a /b ratio of 2 .5 -3 . When the plants are grown under cycles of 2 min light/118 min dark, the respective values are 50 and 5 — 9. With chloroplasts with low chlo­ rophyll b content variable fluorescence is depressed by about 30% by MgCl2; with those of high chlorophyll...

This study described the behavior of the swamp-dwelling African cyprinid Barbus neumayeri in response to laboratory acclimation to normoxic and hypoxic conditions to detect costs associated with hypoxia exposure. Behavioral observations were conducted every two weeks over a four-week acclimation period in both normoxic and hypoxic conditions, and feeding trials were conducted after six weeks of...

Cyclodextrins, a class of cyclic oligomeric compounds consisting of 6–8 units of D-glucose, alter the oxygen evolution of photosystem II (PSII) in barley thylakoids as well as chlorophyll a fluorescence induction, i.e., Fv/Fo and Fv/Fm where Fm is the maximal level of fluorescence when all PSII centres are closed, Fo is the minimal level of chlorophyll fluorescence when all PSII centres are ope...

We contrived a color-imaging manner in histodiagnosis of cancer and evaluated its clinical feasibility and significance. Cancer was microscopically detected by identifying specific reddish pink fluorescence emitted from cancer cells under blue light irradiation, which was based on a photodynamic diagnosis (PDD) theory. Aminolevulinic acid (ALA) was used to treat the histologic samples. Three di...

Salinity is one of the major abiotic stresses in plants. The aim present study was to determine effects salinity on relatively sensitive Zinnia elegans Jacq. ‘Zinnita Scarlet’ and tolerant marylandica D.M. Spooner et al. ‘Double Zahara Fire Improved’ through a comparative analysis morphological, physiological, anatomic, biochemical traits. Plants were irrigated at five levels salt concentration...

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...

As the nonheterocystous diazotrophic cyanobacterium Trichodesmium lives both at the ocean surface and deep in the water column, it has to acclimate to vastly different irradiances. Here, we investigate its strategy of light acclimation in several ways. In this study, we used spectrally resolved fluorescence kinetic microscopy to investigate the biophysics of photosynthesis in individual cells, ...

Recent in vivo experiments on Atlantic cod (Gadus morhua) acclimated to chronic hypoxia (6-12 weeks at 10 degrees C; Pw(O(2)) approximately 8-9 kPa) revealed a considerable decrease in the pumping capacity of the heart. To examine whether this diminished cardiac performance was due to the direct effects of chronic moderate hypoxia on the myocardium (as opposed to alterations in neural and/or ho...