Fig. 6: FUST1 is required for thermotolerance.

a Scheme of heat exposures in basal and acquired tolerance assays. b Left, cell death staining of Arabidopsis roots upon heat stress treatment at 42 °C for 2 h. Scale bars, 100 μm. Right, the percentage of seedlings containing cell death. Error bars indicate mean ± SD (n = 3). Twenty seedlings were assayed in each replicate. P values were calculated using two-sided Student’s t-test. ***P < 0.001, ****P < 0.0001. ns no significance. c Germination rate of Arabidopsis seeds after heat treatment at 50 °C for 60 min. Error bars indicate mean ± SD (n = 4). Each replicate contains 49 seeds. P values were calculated using two-sided Student’s t-test. **P < 0.01. d, f Phenotypes of indicated seedlings assayed for basal (d) or acquired (f) heat tolerance. Pictures were taken at seven days (d) or four days (f) of recovery after treatment as indicated. Scale bars, 0.5 cm. e, g Quantification of the damage rate and fresh weight of seedlings shown in d, f. Error bars indicate mean ± SD (n = 3). At least 50 seedlings were assayed for each replicate. P values were calculated using two-sided Student’s t-test. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001.