Fig. 5. Cryoinjury to R. sylvatica organ samples incubated in PBS (no urea) or PBS containing 80 mmol l^-1 urea and frozen at -4°C. Damage was assessed from LDH leakage from frozen/thawed samples; values were standardized to sample dry mass. Asterisk denotes that the mean value (± S.E.M., N=8 replicates per group) for urea-treated samples differed significantly (Wilcoxan signed-rank test; P<0.05) from the mean for samples tested in the absence of urea.