Figure 8.

Functional analysis of Arabidopsis Rabe1b in the heat tolerance of Arabidopsis seedlings. A, Assays of the heat tolerance of young seedlings. Approximately 50 2-week-old seedlings of wild-type Col-0, the rabe1b-1 mutant, and the rabe1b mutant complemented with the Rabe1b, Rabe1b-GTP, or Rabe1b-GDP transgene were placed in a 45°C growth chamber for 9 h. The heat-treated plants were then moved to a 23°C growth chamber for recovery. The photograph was taken 5 d after the heat treatment. B, Survival rates of heat-stressed young seedlings determined after treatment at 45°C for 9 h followed by 23°C for 5 d for recovery. Means and se were calculated from survival rates determined from three experiments with approximately 100 seedlings per experiment for each genotype. According to Duncan’s multiple range test (P < 0.01), means of survival rates do not differ significantly if they are indicated with the same letter.