Chitosan-Elicited Callose Synthesis in Soybean Cells as a Ca²⁺-Dependent Process

Abstract

A new method for the rapid and quantitative fluorometric determination of callose is described. In suspension-cultured cells of Glycine max, synthesis of callose starts within 20 minutes of treatment with chitosan and parallels over hours the accumulation of 1,3-linked glucose in the wall. Poly-L-lysine also elicits callose synthesis. The effect of chitosan is enhanced by Polymyxin B at low concentrations; this antibiotic alone at higher concentrations can also induce callose synthesis. Callose synthesis is immediately stopped when external Ca2l is bound by ethylene glycolbis-(2-aminoethyl ether)-N,N'-tetraacetate or cation exchange beads, and partly recovers upon restoration of 15 micromolar Ca21.Callose synthesis is observed only when membrane perturbation causing electrolyte leakage from the cells is induced by one of the above treatments. It does not appear to be due to de novo synthesis or proteolytic activation of 1,3-#-D-glucan synthase. It is concluded that this Ca24-dependent enzyme is directly activated by the influx of Ca24 occurring concomitantly with the leakage of cell constituents. This suggestion is also discussed in conjunction with the chitosan-induced synthesis of phytoalexin in the same cells.

Studies on cell wall regeneration in protoplast culture of legumes - the effect of organic medium additives on cell wall components

“…Chitosan is quite often used in plant tissue culture as a cell-stimulating additive (Kowalski et al 2006;Nge et al 2006). This compound induces cellular defence responses against various stresses, including callose formation (Köhle et al 1985). This is in agreement with our results, since for both species callose deposits were intensively synthesized in the chitosan-containing medium.…”

Chitin and chitin-related compounds in plant–fungal interactions

“…These reactions include the following: ion flux variations, cytoplasmic acidification, membrane depolarisation and protein phosphorylation (Felix et al 1993, 1998), chitinase and glucanase activation (Roby et al 1987; Tayeh et al 2015), lignification (Kawasaki et al 2006; Ali et al 2014), generation of reactive oxygen species (ROS) (Kuchitsu et al 1995), biosynthesis of jasmonic acid (JA) (Nojiri et al 1996), and phytoalexins (Ren and West 1992; Yamada et al 1993), and the expression of early responsive and defence-related genes (Minami et al 1996; Libault et al 2007). Moreover, chitosan induces proteinase inhibitors (Walker-Simmons and Ryan 1984), phytoalexin biosynthesis (Hadwiger and Beckman 1980) and callose formation (Köhle et al 1985) in dicot species. The plants’ response to chitin, chitosan and the derived oligosaccharides depends on the acetylation degree (Akiyama et al 1995; Cord-Landwehr et al 2016; Li et al 2016) and the degree of polymerisation (Walker-Simmons and Ryan 1984; Li et al 2016).…”

Apoplastic Binding of Aluminum Is Involved in Silicon-Induced Amelioration of Aluminum Toxicity in Maize

“…After homogenization, another 500 mL of 1 M NaOH was added, and callose was extracted for 30 min at 80°C in a water bath. Callose was quantified fluorometrically according to Kö hle et al (1985), using aniline blue as color reagent (Hitachi f2000; Hitachi, Tokyo; excitation 393 nm and emission 484 nm).…”