Fig. 5.

Effect of moderate heat stress on the de novo synthesis of acpPC protein and the relative steady-state level of acpPC mRNA. OTcH-1 and CS-73 cells (10 μg of Chl per 1 ml in 0-h sample) were preincubated at 25°C or 34°C under 200 μmol photons m⁻² s⁻¹ for the times shown before incubating with [³⁵S]methionine/cysteine (10 μCi ml⁻¹) for 90 and 30 min at 25°C and 34°C, respectively. (A) Autoradiograph signal of [³⁵S]-labeled acpPC in isolated thylakoid membrane proteins (corresponding to 1.5 μg of Chl in 0-h sample) separated by SDS/PAGE. The levels of acpPC relative to the 0-h sample from two independent experiments are shown in brackets. (B) The level of acpPC transcript level was measured before and after incubation in light at 25°C and 34°C for 24 h and normalized to the ub52 transcript level that remained relatively constant (18). The values are means ± SD (bars) of results from three independent experiments.