Induction of cold active acid phosphomonoesterase activity at low temperature in psychrotrophic ectomycorrhizal Hebeloma spp.

Hebeloma strains of arctic and temperature origin, grown at 22 degrees or 6 degrees, were assayed for wall-bound and extracellular acid phosphomonoest erase (pNPPase) across a temperature range 2-37 degrees. Only when grown at 6 degrees was a cold active extracellular pNPPase induced in all the arcti c strains and most of the temperature strains tested. Such enzymes are sugg ested to be a adaptation to low soil temperatures, and are discussed in the context of ectomycorrhizal access to soil PO4- monoesters at low temperatu re.