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...

background & aim: the pigments inside the leaf chloroplasts receive sunlight energy and transport it to photosynthesis reaction center. the most important of these pigments is chlorophyll. in this study, the pigments existence in medicinal plant, sumac (rhus coriaria l.), was investigated at biotechnology laboratory, isfahan university of technology. experimental: experiments were performed...

Plants have an ability to prevent chlorophyll accumulation, which would mask the bright flower color, in their petals. In contrast, leaves contain substantial amounts of chlorophyll, as it is essential for photosynthesis. The mechanisms of organ-specific chlorophyll accumulation are unknown. To identify factors that determine the chlorophyll content in petals, we compared the expression of gene...

to explore the function of light-harvesting complex protein (lhcp) in arabidopsis growth and development, the leclere and bartel seed collection was screened. in this collection randomly cloned cdnas are expressed under the camv35s promoter. a pale green line has been identified and characterized in more details. analysis of the inserted cdna in the pale green line showed it encodes lhcb1 prote...

cold stress is considered as a restricting factor in plant production. recently, many different compounds were applied to minimize the harmful effects of stress. in this study, the effects of foliar application of salicylic acid was studied on some biochemical properties of two different cold resistant canola cultivars. salicylic acid was sprayed at four concentrations (0, 100, 200 and 400 µm) ...

we studied the role of nutrients on various aspects of the periphyton community in artificialstreams. dry mass, ash-free dry mass, chlorophyll a and biovolume of the periphyton community weremeasured under 3 different nutrient regimes, including one from natural streams as a control and twowhich were enriched with n and n+p. results of this experiment indicate that the standing crop of theperip...