Responses of pPLAIIIγ-KO, COM and WT Arabidopsis plants to sorbitol and polyethylene glycol (PEG). (a) Representative images under different sorbitol and PEG concentrations; (b, c) quantification of seedling growth in response to different levels of sorbitol. Three-day-old seedlings germinated on ½ MS media after stratification were transferred to plates with 0, 100, 150, 250 and 300-mM sorbitol. Seedlings were harvested and measured 7 days after transferring; (d,e) quantification of seedling growth in response to different levels of PEG. Values are mean ± SE from three biologic repeats for dry weight of each line in (c). Error bars indicate the SE (n = 45–60) in (b,d,e) for primary root length. One and two asterisks indicate significant differences from WT by Student’s t-test at p = 0.05 and p = 0.01, respectively.