Early events induced by chitosan on plant cells

Abstract

Chitosan (a polymer of beta-1,4-glucosamine residues) is a deacetylated derivative of chitin which presents antifungal properties and acts as a potent elicitor of plant resistance against fungal pathogens. Attention was focused in this study on the chitosan-induced early events in the elicitation chain. Thus, it was shown that chitosan triggered in a dose-dependent manner rapid membrane transient depolarization of Mimosa pudica motor cells and, correlatively, a transient rise of pH in the incubation medium of pulvinar tissues. By using plasma membrane vesicles (PMVs), it was specified that a primary site of action of the compound is the plasma membrane H(+)-ATPase as shown by its inhibitory effect on the proton pumping and the catalytic activity of the enzyme up to 250 microg ml(-1). As a consequence, chitosan treatment modified H(+)-mediated processes, in particular it inhibited the uptake of the H(+)-substrate co-transported sucrose and valine, and inhibited the light-induced H(+)/K(+)-mediated turgor reaction of motor cells. The present data also allowed the limit of the cytotoxicity of the compound to be established close to a concentration of 100 microg ml(-1) at the plasma membrane level. As a consequence, chitosan could be preferably used in plant disease control as a powerful elicitor rather than a direct antifungal agent.

A Review of the Applications of Chitin and Its Derivatives in Agriculture to Modify Plant-Microbial Interactions and Improve Crop Yields

“…Various studies have analysed the defenses activated by chitin and include the production, release, and/or activation of phytoalexins [122,123], phenolics [124], terpenes [23], and reactive oxygen species [125]. Cellular changes detected following chitin derivative application include membrane depolarization resulting in alterations in ion fluxes and cytoplasmic acidification [125,126].…”

A Prominent Role of the Flagellin Receptor FLAGELLIN-SENSING2 in Mediating Stomatal Response to Pseudomonas syringae pv tomato DC3000 in Arabidopsis

“…Stomatal guard cells also respond to purified microbe-associated molecular patterns (MAMPs), such as chitosan, a polymer of b-1,4-glucosamine residues derived from fungal chitin (Lee et al, 1999;Amborabe et al, 2008), flg22, a 22-amino acid peptide derived from bacterial flagellin (Melotto et al, 2006;Cho et al, 2008;Desikan et al, 2008;Zhang et al, 2008), and bacterial lipopolysaccharides (LPSs; Melotto et al, 2006;Cho et al, 2008). Peptidoglycan, derived from Gram-positive bacteria, is shown to be able to induce plant innate immune responses (Gust et al, 2007;Erbs et al, 2008).…”

Exploiting Plant Innate Immunity to Protect Crops Against Biotic Stress: Chitosaccharides as Natural and Suitable Candidates for this Purpose

“…This process provokes an alkalinization of the apoplast and an acidification of the cytoplasm ( Recently, Amborabé and coworkers (2008) demonstrated membrane depolarization and the rise of pH of culture media in Mimosa pudica cells elicited by chitosan. By using plasma membrane vesicles they detected an inhibition by chitosan on the proton pumping and in the catalytic activity of the H + ATPase enzyme at least 30 minutes after the elicitor treatment that disturb the H+ fluxes and in consequence it modified the membrane transport of nutrients (Amborabé et al, 2008 (Kawano et al, 1999;Zuppini et al, 2003;Li et al, 2009). For instance, Ca 2+ , a second messenger in defense reactions that enters in the cytoplasm upon PAMP activation, has been reported to accumulate H 2 O 2 previous to gene activation and cell death in soybean cells (Zuppini et al, 2003).…”