Figure 3.

RNA Gel Blot Analysis of the Steady State Amounts of PcGST1 and CHS Transcripts and Ubiquitin Concentrations in Response to UV-B Light, Hormone, and Elicitor Treatment.

(A) Detection of transcripts in response to exposure to UV-B light, treatment with 2,4-D, or both. Parsley cells were kept in darkness (D) or irradiated with a pulse of UV-B light through a 305-nm cutoff filter and kept in the dark until harvest after 2 hr (UV-B 2 hr) or 6 hr (UV-B 6 hr). Simultaneously, 4.5 μM 2,4-D was added to dark-incubated cells, which were then either irradiated with UV-B light or kept in darkness until harvest. RNA gel blot analysis was performed with 20 μg of total RNA, as described in Methods. Filters were probed with cDNA inserts for PcGST1, CHS, and ubiquitin (UBI) for loading control analysis.

(B) Detection of transcripts in the absence of intact protein synthesis. Shown is PcGST1 and CHS mRNA accumulation of cells after 30-min pretreatment with 30 μM cycloheximide (CHX), inhibiting protein synthesis and subsequent dark incubation or UV-B irradiation, as described in (A).

(C) Detection of transcripts in response to treatment with the synthetic elicitor Pep25 or the auxin analogs α-NAA and β-NAA. Shown is PcGST1 mRNA accumulation after treatment of dark-incubated cells with 175 nM Pep25, 10 μM α-NAA, or 10 μM β-NAA. All cells were kept in darkness until harvest after 2 hr.