Figure 5.

CDK8 Is Required for the Accumulation of Arabidopsis HCAAs.

(A) Expression of the AACT1 gene in response to B. cinerea and A. brassicicola. RNA was extracted from mock-, B. cinerea-, or A. brassicicola-inoculated leaves. The experiment was repeated three times. Error bars indicate se (n = 3).

(B) Detection of HCAAs from rosette leaves of 5-week-old Arabidopsis wild-type and cdk8 plants at 48 h after inoculation with A. brassicicola. The data are mean values ± se from two biological replicates (n = 4). FerAgm, feruloylagmatine; CouAgm, p-coumaroylagmatine; FerPtr, feruloylputrescine; CouPtr, p-coumaroylputrescine.

(C) CDK8 is specifically recruited to a 500-bp region upstream of the AACT1 promoter region.

(D) Recruitment of CDK8 to the AACT1 gene is enhanced by B. cinerea infection.

In (C) and (D), chromatin was extracted from 5-week-old cdk8;35S:CDK8-MYC #7 transgenic plants that were mock- or B. cinerea-inoculated. Error bars indicate se (n = 3). ChIP-qPCR experiments were repeated two times with similar results. No Ab, negative control with no antibody.

The data were statistically analyzed. Asterisks indicate significant differences (Student’s t test, *P < 0.05, **P < 0.01).