To determine the effect of the T3SS
mutation on A. citrulli pathogenicity, 2-week-old watermelon seedlings
(‘Sugar Baby’) were infiltrated as described above with
AAC00-1ΔhrcC, AAC00-1ΔhrcCcomp AAC00-1 (wild-type) at
approximately 1 × 106 CFU/ml, or PBS as a negative control. The
cotyledons of three seedlings were inoculated (28) and plants were
incubated for 2 days at 28°C with approximately 75% RH and 12 h
of fluorescent light daily in a growth chamber. Plants were then
visually observed for BFB symptoms (necrosis