Figure 8

Oxidative stress tolerance of the wild-type Anabaena PCC7120 (WT) and An4641 ⁺ . (A) Three-day-old Anabaena cultures were inoculated in a fresh growth medium and subjected to H₂O₂ (1 mM) stress for 2 days. Later, cultures were transferred onto a microtitre plates and photographed. (B) The chlorophyll a content of cultures shown in (A) was determined immediately (day 0) or after two days of exposure to H₂O₂. (C) Rapid light curves of ETR (II). Data were collected through the light response reaction from untreated (control cells) or cells treated with H₂O₂ (1 mM) as indicated in the figure. (D) The rate of ¹⁴CO₂ fixation [μmoles of CO₂ fixed (μg chlorophyll a)⁻¹ h⁻¹] of the wild-type Anabaena PCC7120 (WT) or An4641⁺ cells after treatment with 1 mM H₂O₂ for 24 h. (E) The wild-type Anabaena PCC7120 (WT) or An4641⁺ cells after treatment with H₂O₂ (1 mM) for 2 days were spotted (100 μl each) on BG-11 agar plate. The plates were incubated under continuous illumination and photographed after 14 days of incubation.