FIG. 5.

Phenotypic analysis of the hrpF mutant derived from X. oryzae pv. oryzicola. The hrpF mutant had lost pathogenicity in adult rice (IR24) when inoculated into leaves by using leaf needling for lesion length measurements (B) and had lost the hypersensitive response in tobacco (Nc89) when infiltrated into leaves with needleless syringes (C), but it retained to the ability to cause water-soaking symptoms in rice seedlings (A). A. Water-soaking symptoms caused by the hrpF mutant. The third leaf of 14-day-old IR24 seedlings was infiltrated using needleless syringes individually with the wild-type strain RS105 harboring pUFR034 (empty plasmid) (1), RFBC (hrpF mutant) (2), RFBC harboring p6 (the core hrp cluster) (3), and RFBC harboring pHrpF (the hrpF gene) (4). The water-soaking symptoms after 3 days of infiltration are shown. B. Measurements of lesion length caused by hrpF mutants. The third leaf of IR24 adult plants was inoculated with corresponding bacteria as described above, using leaf needling. The lesion lengths after 14 days are shown. C. Hypersensitive response in tobacco induced by hrpF mutants. The leaves were infiltrated using needleless syringes with the bacteria as described above, and the reaction was recorded within 24 h. Three replicates were conducted for identification of the phenotypes.