Free radical production by the red tide alga,Chattonella antiqua

Abstract

The red tide alga, Chattonella antiqua, was found to show a strong chemiluminescence, using luminol as the reagent, when exposed to ultraviolet irradiation. This luminescence was completely inhibited by ascorbate or catalase, suggesting that hydrogen peroxide was generated by the plankton. Red tide cells exposed to fish gill mucus from young yellowtail resulted in the release of a large number of mucocysts and a weak luminosity, and showed a strong reduction of cytochrome c in the medium. Therefore, the discharge of mucocysts from the red tide, induced by the presence of gill mucus, may be accompanied by the release of active oxygen species. The active oxygen may be involved in depolymerization of mucus glycoproteins from the gill lamellae.

Parallel Changes in H2O2 and Catalase during Thermotolerance Induced by Salicylic Acid or Heat Acclimation in Mustard Seedlings1

“…The amplitude of the H 2 O 2 increase is also similar to that reported by Chen et al (1993), following a continuous 24-h injection of a 1 mm SA solution into petioles of tobacco plants. It is tempting to associate this H 2 O 2 increase with an oxidative burst similar to that observed during other forms of abiotic stress (Shimada et al, 1991;Doke et al, 1994;Sgherri et al, 1996;Sharma et al, 1996), including chilling (Omran, 1980;Okuda et al, 1991;Prasad et al, 1994), and during incompatible pathogen interactions (Apostol et al, 1989;Chen et al, 1993;Doke et al, 1994;Tenhaken et al, 1995). Recent work by LopezDelgado et al (1998) also implicates H 2 O 2 in the signal transduction sequence inducing thermotolerance, since tissues of potato microplants grown from explants incubated with H 2 O 2 showed enhanced thermotolerance.…”

Antioxidant responses and lipid peroxidation in gills and erythrocytes of fish (Rhabdosarga sarba) upon exposure to Chattonella marina and hydrogen peroxide: Implications on the cause of fish kills

“…Several studies postulated that ROS produced by C. marina were the principal ichthyotoxic agent (Shimada et al, 1991(Shimada et al, , 1993Oda et al, 1992aOda et al, , 1992bOda et al, , 1994Oda et al, , 1995Oda et al, , 1997Tanaka et al,. , 1994Tanaka & Muto, 1992;Kim et al, 2000).…”

“…(Shimada et al, 1991(Shimada et al, , 1993Oda et al, 1992aOda et al, , 1992bOda et al, , 1994Oda et al, , 1995Oda et al, , 1997Kim et al, 1999a). No conclusive scientific evidence is, however, available to prove any of these inferences.…”

Clearance effects of the Pacific oyster Crassostrea gigas on the fish-killing algae Chattonella marina and Chattonella antiqua

“…One proposed mechanism is the production of brevetoxin or brevetoxinlike compounds, which have been demonstrated in laboratory cultures of C. marina and C. antiqua (Ahmed et al 1995, Khan et al 1996. A second proposed mechanism is that Chattonella cells also generate reactive oxygen species (ROS) such as superoxide anions (O 2 -), hydrogen peroxide molecules (H 2 O 2 ) and hydroxyl radicals (·OH) (Shimada et al 1989, 1991, 1993, Oda et al 1992a,b, 1994, 1997, Tanaka et al 1992, Kawano et al 1996. These products may damage the cell membranes of fish, especially the cell membrane of gill tissue, leading to death.…”