The Activation of Phytophthora Effector Avr3b by Plant Cyclophilin is Required for the Nudix Hydrolase Activity of Avr3b
Fig 5
Avr3b recognition in soybean is dependent on the PPlase activity of GmCYP1.
(A, B) CsA suppresses Avr3b-triggered cell death in soybean leaves. (A) Soybean cultivars Williams (rps3b) and PRX146-36 (Rps3b) were transformed by co-bombardment with a plasmid mixture consisting of a β-glucuronidase (GUS) expression vector and Avr3b or empty vector (EV). Soybean leaves were sprayed 20 μM CsA solution immediately after bombardment and incubated for 2 days in darkness at 28°C. The leaves were then stained using X-gluc. Scale bars, 3mm. (B) Percentage rate of GUS-positive blue spots following bombardment with Avr3b compared with EV. Bars represent standard errors from four independent replicates. **, t test P<0.01. (C, D) CsA could not suppress Avr1b-triggered cell death. (C) Avr1b was transiently expressed in soybean cultivars Williams (rps1b) and L77-1863 (Rps1b) by co-bombardment with GUS expression vector and Avr1b or EV. The leaves were incubated for 2 days in darkness at 28°C after bombardment, and then stained using X-gluc. Scale bars, 3mm. (D) Percentage rate of GUS-positive blue spots following bombardment with Avr1b compared with the empty vector. Bars represent standard errors from four independent replicates. **, t test P<0.01. (E, F) Avr3b failed to induce Rps3b-mediated cell death in GmCYP1-silenced soybean leaves. (E) Avr3b was delivered into leaves of soybean cultivars Williams (rps3b) and PRX146-36 (Rps3b) together with a GmCYP1-RNAi construct by co-bombardment. The leaves were incubated for 2 days in darkness at 28°C after bombardment, and then stained using X-gluc. Scale bars, 3mm. EV was used as a negative control. (F) Percentage rate of GUS-positive blue spots following bombardment with Avr3b compared with the EV in the presence of GmCYP1-RNAi. Bars represent standard errors from four independent replicates. **, t test P<0.01.