The assay for H2Ocontent was carried out by the procedure previously described by Patterson, Macrae, and Ferguson (1984). Mushroom tissues (2 g) were homogenised with 10 ml of acetone at 0 C. After centrifugation for 15 min at 6000g and 4 C, the supernatant phase was collected. The supernatant (1 ml) was mixed with 0.1 ml of 5% titanium sulphate and 0.2 ml ammonia, and then centrifuged for 10 min at 6000g and 4 C. The pellets were dissolved in 3 ml of 10% (v/v) H22SO and centrifuged for 10 min at 5000g. Absorbance of the supernatant phase was measured at 410 nm. H2O24content was calculated using H2O as a standard and then expressed as 1062 mol/g and per g is on the fresh weight basis.