Figure 4.

The PCNA Promoter Is Activated in Mature Leaves of TGMV-Infected Plants.

(A) Soluble protein extracts were isolated 14 days after inoculation from N. benthamiana lines (left) carrying the −633 PCNA:uidA construct and assayed for GUS (Gus) activity. The activity ratios for infected versus mock-inoculated plants are shown for young (gray bars) and mature (black bars) leaves. Each set of bars represents the mean ratios from three independent experiments. The ratio values for mature leaves are given at right. The dotted line corresponds to a ratio of 1.

(B) Same as in (A) except that the N. benthamiana lines were transformed with the −633 PCNA:luc construct and ratios of Luc activity are shown.

The error bars indicate two standard errors.