Figure 4.

B. cinerea-Induced 4MI3G Biosynthesis Is Compromised in mpk3 mpk6 Double Mutants.

(A) and (B) Steady state levels of I3G (A) and 4MI3G (B) in 12-d-old Col-0 and chemical-genetically rescued mpk3 mpk6 double mutant seedlings after B. cinerea (Bc) inoculation. Col-0, MPK6SR, and MPK3SR seedlings were pretreated with DMSO (solvent of NA-PP1 stock) or NA-PP1 (final concentration of 2.5 μM) for 30 min before Bc inoculation. Samples were collected at indicated times for GS assay.

(C) Ratios of steady state levels of 4MI3G and I3G in Col-0, MPK6SR, and MPK3SR seedlings after Bc inoculation. Error bars indicate sd (n = 3). Differences in IGS contents between DMSO and NA-PP1 pretreatment groups were analyzed by two-way ANOVA. Different lowercase letters above the brackets indicate statistically different groups (P < 0.01). MPK6SR genotype: mpk3 mpk6 P_MPK6:MPK6^YG line #58; MPK3SR genotype: mpk3 mpk6 P_MPK3:MPK3^TA line #17.