Figure 2.

Auxin mutant slr1 shows hypersensitive response to cold stress: (A) Comparison of primary root elongation at optimal temperature (23 °C) and 12 h cold-stressed seedlings in wild type (Col-0) and slr1. Note that slr1 shows slower root growth recovery compared with wild type at all time points we tested. Vertical bars represent mean ± SE. Data are from at least three independent experiments (n = 3 or more) with 8–10 seedlings per treatment. slr1 root growth recovery at 4 °C was statistically significant at all time points as judged by the Student’s t-test. (B) Root phenotype of Col-0 and slr1 during 24 h recovery period after cold stress at 4 °C for 12 h. Tick marks indicate the starting point of the recovery at 23 °C. Scale bar = 10 mm.