Activity of native hydrolytic enzymes and their association with the cell wall of three ectomycorrhizal fungi

作者：Perez de Mora Alfredo^*; Reuter Bianca; Lucio Marianna; Ahne Alfred; Schloter Michael; Pritsch Karin

来源：Mycorrhiza, 2013, 23(3): 185-197.

DOI：10.1007/s00572-012-0461-z

• Cell wall-bound enzymes
• Paxillus involutus
• Piloderma croceum
• Rhizopogon roseolus
• Sequential extraction
• Multivariate analysis
• General linear model

The ecological and biogeochemical relevance of hydrolytic enzymes associated with the fungal cell wall has been poorly studied in ectomycorrhizal (ECM) fungi. We used a modified sequential extraction procedure to investigate the activity of various hydrolytic enzymes (beta-glucosidase, acid-phosphatase, leucine-aminopeptidase, chitinase, xylanase and glucuronidase) and their association with the cell wall of three ECM fungi (Rhizopogon roseolus, Paxillus involutus and Piloderma croceum). Fungi were grown on C-rich solid medium under three different P concentrations (3.7, 0.37 and 0.037 mM). The sequential extraction procedure classifies enzymes as: (a) cytosolic, (b) loosely bound, (c) hydrophobically bound, (d) ionically bound and (e) covalently bound. Results showed that for the same fungus absolute enzymatic activity was affected by P concentration, whilst enzymatic compartmentalization among the cytosol and the cell wall fractions was not. The association of enzymes with the cell wall was fungus- and enzyme-specific. Our data indicate also that enzymes best known for being either extracellular or cytosolic or both, do act in muro as well. The ecological implications of cell wall-bound enzymes and the potential applications and limitations of sequential extractions are further discussed.

• 出版日期2013-4