Figure 7.

Pst T3E HopM1 is required for proteasome inhibition during the Pst-Arabidopsis interaction. A, Proteasome activity (in relative fluorescence units [RFU]) in leaves of Arabidopsis plants infected with Pst wild-type bacteria, Pst ∆hrcC, and Pst ∆CEL harboring HopM1. Samples were taken 2 dpi, and the relative proteasome activity was determined. Each bar represents the mean of three biological replicates ± sd. MgCl₂ infiltration serves as a mock control. Asterisks indicate statistical differences according to Student’s t test (* P < 0.05 and ***, P < 0.001). The experiment was repeated three times with similar results. B, Accumulation of ubiquitinated proteins in Arabidopsis leaves after infection with different Pst strains determined using an anti-ubiquitin antibody. C, Proteasome activity in leaves of Arabidopsis plants infected with Pst wild-type bacteria, Pst ∆hrcC, and Pst ∆hopM1. Samples were taken 2 dpi, and the relative proteasome activity was determined. Each bar represents the mean of three biological replicates ± sd. MgCl₂ infiltration serves as a mock control. Asterisks indicate statistical differences according to Student’s t test (*, P < 0.05). The experiment was repeated two times with similar results. D, Accumulation of ubiquitinated proteins in Arabidopsis leaves after infection with different Pst strains determined using an anti-ubiquitin antibody. All experiments including the Pst ∆CEL and ∆hopM1 strains were carried out three times with similar results.