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 ...

the effects of water deficit on grain yield, yield components and the physiological char-acteristics of barley (hordeum vulgare l.) varieties were studied in a split plot design dur-ing the 1999-2000 growing season in karaj, iran. five irrigation levels [0, 25, 50, 75, and 100% crop water requirements (cwr)] and six barley varieties karoon kavir , rei-hani(drought tolerant), torkman , c-74-9 (i...

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...

Spectral reflectance and chlorophyll fluorescence are rapid non-invasive methods that can be used to quantify plant stress. Because variation in ambient light (e.g., diurnal patterns of solar radiation) may have a confounding effect on these measurements, branches are often excised in the field and then measured under controlled conditions in the laboratory. We studied four temperate tree speci...

The effects of water deficit modelling by polyethylene glycol (PEG), metal nanoparticles (NPs) and their combined action on status, chlorophyll fluorescence pigments composition in the leaves three drought tolerant wheat genotypes – Triticum aestivum L. (Trypilska Favorytka cultivars) dicoccum Schrank. (cv. Holikovska), have been studied. Water deficit, induced PEG, as well treatment with NPs (...

salinity is one of major stresses which can severely limit plant production, especially in the arid and semi-arid regions. the present study was carried out to evaluate the impact of salinity stress on some physio-biochemical parameters in nitre bush plants (nitraria schoberi). thus, an experiment was carried out under natural conditions and salinity stress was induced by a combination of diffe...

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, ...

This paper demonstrates Pseudomonas cepacia lipase catalyzed hydrolysis of p-nitrophenyl palmitate under irradiation of light with wavelengths of 250-750 nm. The reaction follows Michaelis-Menten Kinetics and the light irradiation increases the overall rate of hydrolysis. Using Lineweaver-Burk plot K M and V max values for the reaction in presence of light are found to be 39.07 and 66.67 mM/min...

to comparison the photosynthetic parameters and leaf chlorophyll content and fluorescence of safflower (carthamus tinctorios l.) cultivars under salinity stress, a pot experiment was carried out as factorial based on completely randomized design with three replications in summer 2011 in university of yasouj. first factor included four salinity levels (zero, 75, 150 and 225 mm (formed as 20 to 1...

Here we document physiological and molecular attributes of three wheat cultivars (ZM9023, YM158 FM1228) under low light intensity with advanced technologies, including non-standard quantitative technology proteomics technology. We found lower dry matter accumulation compared ZM 9023 FM1228 intensities due to up-regulation photosynthetic parameters electron transport rate (ETR), Y(II), Fv/Fm, Ch...