Microorganisms that participate in biochemical cycles in wetlands.

Several biochemical cycles are performed in natural wetlands (NWs) and constructed wetlands (CWs). Knowledge of microorganisms can be used to monitor the restoration of wetlands and the performance of wastewater treatment. The phylum is the most abundant in NWs and CWs, which plays a role in nitrogen (N), phosphorus (P), and sulfur (S) cycles, and in the degradation of organic matter.

Seaweed polysaccharides and derived oligosaccharides stimulate defense responses and protection against pathogens in plants.

Plants interact with the environment by sensing "non-self" molecules called elicitors derived from pathogens or other sources. These molecules bind to specific receptors located in the plasma membrane and trigger defense responses leading to protection against pathogens. In particular, it has been shown that cell wall and storage polysaccharides from green, brown and red seaweeds (marine macroalgae) corresponding to ulvans, alginates, fucans, laminarin and carrageenans can trigger defense responses in plants enhancing protection against pathogens.

Long-term protection against tobacco mosaic virus induced by the marine alga oligo-sulphated-galactan Poly-Ga in tobacco plants.

In order to study the antiviral effect of the oligo-sulphated galactan Poly-Ga, the leaves of tobacco plants Xhanti(NN) were sprayed with water (control), with increasing concentrations of Poly-Ga, for increasing numbers of treatments or cultivated for increasing times after treatment. Control and treated plants were infected with tobacco mosaic virus (TMV) and the numbers of necrotic lesions were measured in infected leaves. The number of necrotic lesions decreased with increasing concentrations of Poly-Ga, with increasing numbers of treatments and with increasing time after treatment, indicating a long-term protection against TMV that mimicks vaccination.

Co-occurring increases of calcium and organellar reactive oxygen species determine differential activation of antioxidant and defense enzymes in Ulva compressa (Chlorophyta) exposed to copper excess.

In order to analyse copper-induced calcium release and (reactive oxygen species) ROS accumulation and their role in antioxidant and defense enzymes activation, the marine alga Ulva compressa was exposed to 10 µM copper for 7 d. The level of calcium, extracellular hydrogen peroxide (eHP), intracellular hydrogen peroxide (iHP) and superoxide anions (SA) as well as the activities of ascorbate peroxidase (AP), glutathione reductase (GR), glutathione-S-transferase (GST), phenylalanine ammonia lyase (PAL) and lipoxygenase (LOX) were determined. Calcium release showed a triphasic pattern with peaks at 2, 3 and 12 h.