Fig. 5.

Improved tolerance of the mutants to heavy metal and oxidative stress. (A) Germination frequency under heavy metal stress. The wild type (wt) and mutant (sue3 and sue4) seeds were sown on 1/2× MS medium (750 μM sulphate) containing heavy metal CdCl₂ of indicated concentrations. For each treatment, 25 seeds of each mutant and the wild type were sown on the same plate. Four replica plates were used. Germination frequency was scored 12 d after sowing. Values represent the mean of >100 seeds and error bars represent SEM. *P <0.01, **P <0.001. (B) Germination frequency under oxidative stress. The wild-type and mutant seeds were germinated on 1/2× MS medium supplemented with paraquat of indicated concentrations. For each treatment, 25 seeds of each mutant and the wild type were sown on the same plate and four replica plates were used. Germination frequencies were scored 12 d after sowing. Values represent the mean of 100 plants and error bars represent SEM. *P <0.01, **P <0.001.