Table 1.
Freezing tolerance of chloroplasts in F3 families of non-acclimated A. thaliana plants
| COR15am-positive
|
COR15am-negative
|
||
|---|---|---|---|
| Line | Fv/Fm (±SE) | Line | Fv/Fm (±SE) |
| Experiment 1: Leaves frozen to −5°C | |||
| 1-5 | 0.747 ± 0.013 | 1-10 | 0.671 ± 0.006 |
| 2-11 | 0.697 ± 0.041 | 1-11 | 0.603 ± 0.030 |
| 5-2 | 0.707 ± 0.006 | 2-8 | 0.614 ± 0.014 |
| 5-8 | 0.737 ± 0.004 | 5-6 | 0.606 ± 0.037 |
| Mean* | 0.722 ± 0.011 | 0.623 ± 0.015 | |
| Experiment 2: Leaves frozen to −6°C | |||
| 1-5 | 0.720 ± 0.018 | 1-6 | 0.620 ± 0.017 |
| 1-4 | 0.729 ± 0.029 | 1-1 | 0.507 ± 0.022 |
| 1-15 | 0.657 ± 0.034 | 2-5 | 0.538 ± 0.035 |
| 3-3 | 0.685 ± 0.010 | 3-1 | 0.528 ± 0.053 |
| Mean* | 0.698 ± 0.013 | 0.548 ± 0.019 | |
Wild-type RLD plants were crossed with T8 plants, and F3 families that either did (COR15am-positive) or did not (COR15am-negative) constitutively produce COR15am were selected. Leaves from nonacclimated plants were frozen to either −5°C or −6°C and thawed; damage to chloroplasts was assessed by determining Fv/Fm. Each of the Fv/Fm values listed was based on testing four leaf samples.
*
Mean Fv/Fm values ± SE for the 16 leaf samples tested for each set of conditions.