SA treatment induces proteasome activity and RPT6 gene expression in N. benthamiana and pepper ECW plants.

(A) Pepper and N. benthamiana leaves were treated with 5 mM SA. Total RNA was isolated at 0 (untreated), 1, 3, 6 hour after SA application. Q-PCR was performed to monitor CaRPT6 and NbRPT6 mRNA levels. Relative expression levels at time points indicated are shown. Actin expression was used to normalize the expression value in each sample, and relative expression values were determined against the average value of the untreated sample. Data represent the mean SD (n = 4). Significant differences were calculated using Student's t-test and are indicated by: *, PN. benthamiana leaves were sprayed with 5 mM SA and proteasome activity in total leaf extracts was determined at time points indicated in the figure by monitoring the breakdown of the fluorogenic peptide sLLVY-NH-Mec at 30°C in a fluorescence spectrophotometer. Data represent the mean SD (n = 3) Significant differences are indicated by asterisks (* P