The Cold-Shock Response in Volvariella Volvacca

The inhibitory effect of cold shock has been shown to cause significant changes in growth and proteinsynthesis in many organisms. In the present study, cold shock response of Volvariella volvacea, known as straw mushroom, was investigated. The mushroom strains used in this study were CCy2101, CKh4501, WKh6501 and WM5302. Among these strains, strain WKh6501 exhibited higher growth at optimum growth temperature when compared to the other strains tested. Growth of the mushroom was drastically decreased when incubation temperatures were below the optimum value. About 52% of growth was decreased when an incubation temperature was decreased from 30 °C to 20 °C. In addition, no growth was observed when the temperature was below 20 °C. Cold stress had an effect for V. volvacea not only on growth but also on protein synthesis. SDS-polyacrylamide gel electrophoresis analysis of the protein extracted from cold stress cells revealed induction of several polypeptides, of which at least one polypeptide with an apparent molecular weight of 24 kDa was markedly increased in all mushroom strains tested. N-terminal sequencing and sequence homology analysis have shown that this protein belonged to the family of the major cold shock induced proteins TIR of Candida glabrata and Saccharomyces cerevisiae.

Keywords: Cold-shock response, Volvariella volvacea, Cold-shock protein (CSP)

Corresponding author: E-mail: portha@kku.ac.th