(A, B) P. capsici infection of N. benthamiana leaves expressing GmTAP1 fused to a nuclear localization signal (NLS), a nuclear exclusion signal (NES), and/or carrying an acetlytransferase-minus mutation (GmTAP1M1), compared to control leaves expressing GmTAP1 or GFP. Infection lesions were observed 48 hr after inoculation with P. capsici strain LT263. (A) Representative photographs under UV (B) Lesion diameters; means ±s.d. of three independent experiments. Different letters indicate statistically significant differences among the samples (p < 0.01, Duncan’s multiple range test). (C, D) Histone acetyltransferase activity of GmTAP1. (C) In vitro assays using chicken core histones as substrate. Acetylation was determined by western blotting using the indicated H3ac, H2Aac, H2A.X or H3 antibodies. C646 is a chemical inhibitor of histone acetyltransferase. (D) In vivo assays following expression of GFP, GmTAP1, NLS-GmTAP1, NES-GmTAP1, or NLS-GmTAP1M1 in N. benthamiana leaves. After 2 days of expression, nuclear proteins were extracted and the levels of histone acetylation were detected by western blotting as in (D). All experiments in (C) and (D) were repeated three times with similar results.