Fig. 9.

mlk1/3/4 mutants have increased sensitivity to MMS treatment. A, representative images of mutant and WT seedlings 15 days after transfer to solid media containing the indicated concentration of MMS. Chlorotic tissue is denoted with a blue arrowhead. Scale bar = 5 mm. B, fresh weight of 21-day-old WT and mutant seedlings grown in the presence of MMS relative to mock treated samples. The average of three biological replicates of ≥10 seedlings each is presented. C, percent of seedlings exhibiting postgermination developmental arrest after 12 days of growth in the presence of 150 ppm MMS. The average of three biological replicates of ≥30 seedlings is presented. B and C, error bars indicate standard deviation. ∗p < 0.05, ∗∗p < 0.01 compared with WT seedlings (Student’s t test). D, representative images of mutant and WT seedlings germinated in the presence of 150 ppm MMS. E, representative images of mutant and WT seedlings irradiated with indicated levels of UV-C. Scale bar = 2 mm. MMS, methyl methane sulfonate.