Figure 8.

RD20 confers stress tolerance. A, RD20 protects leaves from Paraquat toxicity. Green leaves from RD20-overexpressing lines, the rd20 mutant, and their respective controls were counted after 1 week of growth under continuous light in the presence of 0.5 µm Paraquat. The experiment was repeated twice. Data-averaged values are means ± se (n = 60 per genotype; differences were significant at *P < 0.05 and **P < 0.01 when analyzed by Student’s t test). B, RD20 protects against cell death. Cell death was visualized by staining leaves of RD20-overexpressing lines and the rd20 mutant with Trypan Blue (top). Oxylipins were measured from two independent experiments (bottom); data are means ± se and differ between with or without Paraquat (P) at *P < 0.05 (Student’s t test analysis). fw, Fresh weight. C and D, RD20 decreases the accumulation of ROS. H₂O₂ (C) and superoxide radical (D) contents of leaves of transgenic lines and control plants were measured by DAB and NBT staining, respectively. ROS accumulation was estimated by the ratio of stained surface versus total leaf surface using ImageJ (n = 30). Differences between transgenic lines and their respective controls are highly significant with P < 0.01 by Student’s t test. Bars = 1 mm.