Morphological properties and levels of extracellular peroxidase activity and light emission of the basidiomycete Armillaria borealis treated with β-glucosidase and chitinase

Abstract

Mogilnaya OA, Ronzhin NO, Artemenko KS, Bondar VS 2017 -Morphological properties and levels of extracellular peroxidase activity and light emission of the basidiomycete Armillaria borealis treated with β-glucosidase and chitinase. Mycosphere 8(4), 649-659, Doi 10.5943/mycosphere/8/4/11 AbstractThe study estimates morphological properties and levels of extracellular peroxidase activity and light emission of mycelium of the basidiomycete Armillaria borealis IBSO 2328 treated with β-glucosidase and chitinase. Mycelium incubated with the enzymes shows considerable morphological changes and indications of osmotic shock. Injuries observed in the cell envelope of the fungal hyphae are primarily attributed to the partial (in the β-glucosidase treatment) or complete (in the chitinase treatment) disintegration of the melanin layer on the surface of the cell wall. Changes in the cell wall of hyphae are accompanied by release of extracellular peroxidases of the fungus into the incubation medium and an increase in light emission relative to the luminescence of the control pellets. We assume that higher level of luminescence of the enzyme-treated mycelium samples could be related to the disintegration of the surface pigment layer of the hyphae and the partial loss of extracellular peroxidases. The data obtained confirm the previously proposed hypothesis in which light producing reaction of the fungus may be an additional way to neutralize active oxygen radicals under stress.

The functionally conserved effector Sta1 is a fungal cell wall protein required for virulence in Ustilago maydis

“…In contrast to chitinase, which induced changes to intracellular structure, β‐glucanase treatment did not induce such a structural phenotype in filaments constitutively expressing Sta1. We speculate that disruption of the inner chitin layer triggers a much more severe stress response than the response triggered by removal of β‐glucan in the outer layer of the fungal cell wall as previously reported in filaments of another basidiomycete fungus (Mogilnaya et al , 2017).…”

Production of β‐glucosidases by European Armillaria species

“…The relative contribution of each isoenzyme to the hydrolysis of cellulose is unknown. It has been suggested that intracellular β‐glucosidases have important functions in developmental processes in higher fungi, as high amounts of β‐glucans have been found in the cell walls of many fungi including Armillaria (Mogilnaya, Ronzhin, Artemenko, & Bondar, 2017; Smith & Gold, 1979). According to several authors, the soluble internal β‐glucosidase is primarily involved in energy‐assimilating functions because it is rapidly induced by cellobiose, while the external enzyme is produced in the presence of cellulose along with other cellulolytic enzymes (Baldrian & Valášková, 2008; Wilson & Niederpruem, 1967).…”