FIGURE 3.

Co-silencing of SlSAHHs conferred enhanced resistance to P. syringae pv. tomato DC3000. Ten-day-old seedlings were infiltrated with agrobacteria carrying TRV-SlSAHH1/2/3, TRV-SlSAHHa or TRV-GUS constructs and were inoculated by vacuum infiltration with Pst DC3000 (OD₆₀₀ = 0.0002) at 4 weeks after VIGS infiltration. (A) Representative disease symptom on leaves of the TRV-GUS- and TRV-SlSAHH-infiltrated plants. Photos were taken 3 days after inoculation (dpi). (B) Bacterial growth in inoculated leaves of TRV-GUS- and TRV-SlSAHH-infiltrated plants at 0 and 3 dpi. (C) Changes of SAHH activity in TRV-GUS- and TRV-SlSAHHa-infiltrated plants after inoculation with Pst DC3000. (D) SA contents in TRV-GUS- and TRV-SlSAHHa-infiltrated plants without and with inoculation with Pst DC3000. Leaf samples were collected at 24 h after inoculation with Pst DC3000 or with 10 mM MgCl₂ as mock inoculation controls. Similar results were obtained in independent experiments (A) and data presented in (B), (C), and (D) are the means ± SD from three independent experiments. ^∗ above the columns in (B), (C), and (D) indicate significant differences at p < 0.05 level between the TRV-SlSAHHa- and TRV-GUS-infiltrated plants.