Rapid Stimulation of an Oxidative Burst during Elicitation of Cultured Plant Cells

Abstract

Stimulation of cultured plant cells with elicitors of the defense response leads to the rapid destruction of a variety of watersoluble compounds including indoleacetic acid and certain fluorescent dyes. This destructive activity, which is often vigorously manifested within 5 minutes of elicitor addition, is shown to derive from the rapid production of H202 and its use by extracellular peroxidases. Because of its speed of appearance, this oxidafive burst may qualify as the first induced line of defense against invading pathogens. Since H202 has been implicated as a second messenger of hormone-stimulated metabolic changes in some animal cells, its possible role in transduction of the defense signal in plants was also examined. Not only did exogenous H202 alone stimulate phytoalexin production in the plant cell suspension, but inhibition of elicitor-stimulated phytoalexin production was observed upon addition of catalase and other inhibitors of the oxidative burst. Furthermore, for inhibition to occur, the presence of catalase was required during elicitor addition, since if introduction of the enzyme was delayed until 1 hour after addition of the elicitor, no inhibition resulted. These results suggest that H202 also plays an important role in inducing subsequent defense responses such as phytoalexin production.

Increased Polyamine Biosynthesis Enhances Stress Tolerance by Preventing the Accumulation of Reactive Oxygen Species: T-DNA Mutational Analysis of Oryza sativa Lysine Decarboxylase-like Protein 1

“…The antioxidant system in plant cells consists of various radical-scavenging molecules, including low molecular weight antioxidants such as ascorbate, glutathione and carotenoids, as well as antioxidant enzymes such as superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT), glutathione S-transferase (GST) and glutathione reductase. This equilibrium may be perturbed by a number of adverse environmental factors that generate ROS by activating oxidases and peroxidases, or that lead to the rapid accumulation of ROS, a phenomenon known as an oxidative burst (Apostol et al, 1989).…”

Characterization of a CuZn superoxide dismutase gene in the arbuscular mycorrhizal fungus Glomus intraradices

“…In the plant, CuZnSOD expression is usually one of the earliest detectable plant responses to pathogen infection and a key element of the plant defence system (Apostol et al 1989;Mandal et al 2008). In phytopathogenic fungi, there are examples of SODs that contribute to virulence (Rolke et al 2004), but there are also reports where SODs were shown to be dispensable for full virulence (Fang et al 2002;Moore et al 2002).…”

Compromising early salicylic acid accumulation delays the hypersensitive response and increases viral dispersal during lesion establishment in TMV‐infected tobacco

“…HR is not induced following TMV infection of tobacco plants lacking an 'N' gene and viral particles spread systemically through the phloem, resulting in mosaic symptoms developing first in apical leaves. Recognition is rapidly followed by generation of superoxide anions at the cell membrane (reviewed Hammod-Kosack and Jones, 1996;Mehdy, 1994), possibly by an activated NAD(P)H oxidase complex (Apostol et aL, 1989;Auh and Murphy, 1995;Levine et aL, 1994) which rapidly dismutate to H202. Many roles have been proposed for extracellular H202 including oxidative cross-linking of wall-strengthening proteins (Bradley etal., 1992) and direct pathogen toxicity (Peng and Kuc, 1992).…”