The effect of caspase inhibitor on rates of heat-induced AL-PCD in Arabidopsis thaliana. Five day old seedlings of Arabidopsis thaliana, with or without, 1 hr preincubation in 1 μM Ac-DEVD-CHO (caspase-3 inhibitor) were subjected to a heat treatment at 49°C for 10 min or no heat treatment. Root hairs were scored 24 hr later. Root hairs deemed to have undergone cell death, determined by the lack of FDA staining, were scored for AL-PCD characterised by retraction and condensation of the cytoplasm. Those root hairs showing neither FDA staining nor retraction of the cytoplasm, were scored as necrotic. Rates of AL-PCD or Total Cell Death (TCD) (TCD = necrotic + AL-PCD) were plotted. Error bars = standard error of n = 3 replicates.