Fig. 2
Induced resistance in cucumber seedlings in response to two difference dosages of BVCs. a Disease severity (0–5) in BVC-treated cucumber plants recorded at 7 days after challenge with P. syringae pv. lachrymans at OD600 = 1 as follows: 0, no symptoms; 1, yellowish colour; 2, chlorosis only; 3, partial necrosis and chlorosis; 4, necrosis of the inoculated area and expanded chlorosis; and 5, complete necrosis of the inoculated area. Photographs of the lesions were taken at 7 days after infection with P. syringae pv. lachrymans. b Pathogen population measured at 0, 3 and 6 days after challenge with P. syringae pv. lachrymans per leaf disc (diameter = 1 cm). c, d Expression levels of the cucumber resistance genes CsLOX and CsETR1 assessed by qRT-PCR analysis at 0 and 3 h after challenge with P. syringae pv. lachrymans. Air and 1 mM BTH were used as negative and positive controls, respectively. Different letters indicate significant differences between treatments (P = 0.05 according to least significant difference). Error bars indicate the standard error. Each treatment group contained four replicates (four miniature greenhouses). The experiment was repeated three times with similar results