Fig. 1.

Gene expression governed by a unique cis element in Arabidopsis is light- and pathogen-responsive. Histochemical analysis of transgenic Arabidopsis plants expressing a promoter-GUS construct containing a tandem repeat of a unique cis element (see text). (A) Overrepresented cis element identified by MEME and MAST analysis. (B) Four-week-old T₃ plants soil-grown under short (Left) and long (Right) days. (C) Unchallenged, G. orontii, and E. pisi-inoculated (left to right) rosette leaves of 4-wk-old short-day-grown T₃ plants at 3 d after inoculation. (D) Wounded (forceps mark) rosette leaf of 4-wk-old short-day-grown T₃ plant. Similar expression patterns were observed in four independent transgenic lines. (E) Results of quantitative GUS assay on multiple T₂ plants (4–9 per line) of four different transgenic lines upon inoculation with Bgh (at 3 d after inoculation). Values of each line were normalized to the uninoculated control (set as 1); error bars represent the SEM. Asterisks indicate a significant difference from the uninoculated control (*P ≤ 0.05; **P ≤ 0.01; Student's t test). Similar results were obtained in two independent experiments.