AtTIL enhances tolerance to freezing stress. (a) Plants were grown for 3 weeks at 22°C (NA) or grown at 22°C then transferred at 4°C for 7 days (CA7), and pictures were captured. The same plants were subjected to a freeze test performed at -6°C or -10°C for the NA and CA plants, respectively, and pictures were captured after a recovery period of 3 weeks. (b) Survival rate after freezing of NA plants to -6°C, expressed as a percent of surviving plants. Statistical analysis was performed by one-way ANOVA, and the asterisks (*) indicate differences that are significant at the P < 0.001 level. (c) AtTIL protein accumulation in leaves of NA and CA plants. Proteins were extracted and analyzed by immunoblotting. CBB-stained gels are shown as loading controls. Results are representative of at least three independent assays involving 18 plants per line per assay.