Figure 6.

IQM1 indirectly enhances the enzyme activity of ACX2/3 through CAT2. A and B, Expression of ACX2 and ACX3 in iqm1-1 mutants. The expression of the JA biosynthetic enzyme genes ACX2 and ACX3 was assayed in the leaves of wild-type, iqm1-1, and cat2-1 plants. Four-week-old seedlings were subjected to B. cinerea for 3 d. Total RNA was extracted at the indicated times. The transcript levels were quantified by RT-qPCR using ACTIN2 as a control. Independent biological assays were repeated three times, and similar results were obtained. Data from one representative replicate are shown. Values are means with sd from three technical measurements. C, Relative ACX2/3 activity in leaves of 4-week-old wild-type and iqm1-1 mutant plants at 3 d after infection with B. cinerea. All experiments were repeated at least three times. The data shown are means ± sd of three biological repeats. Asterisks indicate significant differences compared with Col-0 (Student’s t test, **, P < 0.01).