Fig. 2.
Effect of moderate heat stress on photobleaching in the light in OTcH-1 and CS-73. (A–C) Equivalent cell samples (2.5 μg of Chl ml−1) were incubated for 24 h at 200 μmol photons m−2 s−1 at the temperatures shown, and differences in their visual coloration (A), cell number (B), and chlorophyll content measured (C). Initial cell numbers and chlorophyll content per cell in OTcH-1 and CS-73 were 7.9 ± 0.8 × 105 and 14.1 ± 1.3 × 105 cells ml−1 and 3.29 ± 0.41 and 1.76 ± 0.32 pg of Chl a and c2 cell−1, respectively. In B and C, the values are means ± SD of three independent experiments. (D) Light microscope (Axioskop; Zeiss) examination of the OTcH-1 and CS-73 cells after treatment.