HopZ1a triggers the degradation of AtJAZ1 during bacterial infection.

(A) HopZ1a, but not AvrRpt2, promotes the degradation of AtJAZ1 in the Arabidopsis ecotype Col-0 (wild-type) during bacterial infection. Six-week 35S-HA-AtJAZ1Arabidopsis transgenic plants were infiltrated with PtoDC3000, PtoDC3118 carrying the empty pUCP18 vector (EV), or PtoDC3118 expressing HopZ1a, HopZ1a(C216A) or AvrRpt2. (B) HopZ1a promotes the degradation of AtJAZ1 in zar1-1 Arabidopsis plants. Six week-old 35S-HA-AtJAZ1 zar1-1 Arabidopsis plants were inoculated with PtoDC3000, PtoDC3118 carrying the empty pUCP18 vector (EV), or PtoDC3118 expressing HopZ1a or HopZ1a(C216A). (C) HopZ1a-mediated degradation of AtJAZ1 is dependent on COI1. 35S-HA-AtJAZ1, coi1-30 Arabidopsis plants were inoculated with PtoDC3000, PtoDC3118 carrying the empty pUCP18 vector (EV), or PtoDC3118 expressing HopZ1a or HopZ1a(C216A). Bacterial infection assays were conducted using inoculums at OD600 = 0.2 (approximately 2×108 cfu/mL). The abundance of AtJAZ1 was determined by western blots using anti-HA antibody at 6 hpi. The protein gels were stained with Coomassie blue as loading controls. These experiments were repeated three times with similar results.