To date, the majority of molecular genetic studies in algae have utilized a fairly limited range of markers such as the plastid rbcL gene and spacer, the mitochondrial cox2-3 spacer or the nuclear ribosomal DNA and spacers. The lack of available markers has been particularly problematic in studies of within-species variation. Whilst microsatellites are now being developed in many algal species,...

Midpoint potentials of plant-type ferredoxins from a range of sources were measured by redox titrations combined with electron-paramagnetic-resonance spectroscopy. For ferredoxins from higher plants, green algae and most red algae, the midpoint potentials (at pH 8.0) were between --390 and --425 mV. Values for the major ferredoxin fractions from blue-green algae were less negative (between --32...

Within the euphotic zone of oceans and lakes, planktonic algae are exposed to concurrent changes in irradiance and spectral quality Most models of photoadaptations, however, consider only the effects of machance. Using a factorial expenmental design, this study evaluated the influence of irradiance and spectral quality on the chemical composition, and rates of carbon uptake, polymer synthesis a...

Many algae are rich sources of sulfated polysaccharides with biological activities. The physicochemical/rheological properties and biological activities of sulfated polysaccharides are affected by the pattern and number of sulfate moieties. Sulfation of carbohydrates is catalyzed by carbohydrate sulfotransferases (CHSTs) while modification of sulfate moieties on sulfated polysaccharides was pre...

Marine algae have unique defense strategies against microbial infection. However, their mechanisms of immunity remain to be elucidated and little is known about the similarity of the immune systems of marine algae and terrestrial higher plants. Here, we suggest a possible mechanism underlying algal immunity, which involves hexose oxidase (HOX)-dependent production of hydrogen peroxide (H2O2). W...

A field experiment was employed in Florida Bay investigating the response of seagrass epiphyte communities to nitrogen (N) and phosphorus (P) additions. While most of the variability in epiphyte community structure was related to uncontrolled temporal and spatial environmental heterogeneity, P additions increased the relative abundance of the red algae-cyanobacterial complex and green algae, wi...

Starch defines an insoluble semicrystalline form of storage polysaccharides restricted to Archaeplastida (red and green algae, land plants, and glaucophytes) and some secondary endosymbiosis derivatives of the latter. While green algae and land-plants store starch in plastids by using an ADP-glucose-based pathway related to that of cyanobacteria, red algae, glaucophytes, cryptophytes, dinoflage...

The early evolutionary history of the chloroplast lineage remains an open question. It is widely accepted that the endosymbiosis that established the chloroplast lineage in eukaryotes can be traced back to a single event, in which a cyanobacterium was incorporated into a protistan host. It is still unclear, however, which Cyanobacteria are most closely related to the chloroplast, when the plast...

The Red Queen Effect is an evolutionary hypothesis [1]. This evolutionary concept is named for the Red Queen ́s comment to Alice in Through the Looking Glass that “it takes all the running you can do, to stay in the same place”. It posits that multicellular organisms with long life cycles must constantly change, adaptation process driven by the changing conditions of the environment, in order to...

This paper shows that in Porphyridium cruentum and in Chlorella pyrenoidosa (but apparently not in Anacystis nidulans) "extreme red" light (> 720 mmu) can inhibit photosynthesis produced by "far red" light (up to 720 mmu). From the action spectrum of this phenomenon, it appears that an unknown pigment with an absorption band around 745 mmu must be responsible for it.