Figure 2.

Regulation of APR by H₂O₂. Arabidopsis plants (Col-0) grown in hydroculture were treated with 10 mm H₂O₂. A, Relative mRNA levels of the three APR isoforms in roots were determined by semiquantitative RT-PCR. Data are presented as ratios of mean transcript levels of four independent RNA preparations from treated versus untreated plants. B, APR activity was measured in crude root extracts. Data are presented as means ± sds of three independent plants. Values indicated by asterisks are different from control at P ≤ 0.05.