Figure 4.

PLD activity in aleurone protoplasts treated with GA or ABA. (A) GA (5 μM) or ABA (5 μM) was applied to protoplasts for various times and PLD activity assayed in vitro as described in Materials and Methods. (B) Protoplasts were incubated in 5 μg/ml cycloheximide for 2 hr and then treated with ABA or GA, and PLD assayed as for A. Mean ± SEM, n = 3 separate experiments. (B Inset) Protoplasts were treated with 5 μM GA, with (+cycl) or without cycloheximide (5 μg/ml) for 48 hr. Protein was extracted, and SDS/PAGE and immunoblotting carried out as described in Materials and Methods.