The Plant Pathology Journal

Fig. 2.

Download original image
Fig. 2. Pathogenicity assays of Burkholderia glumae BGR1 wild-type, PVF11 defective mutant, and PVF11C complemented mutant in rice plants at different growth stages (seedling, vegetative, and reproductive). (A) Photographs from the seedling assay showing a clear deleterious effect of wild-type BGR1 treatment and reduced virulence in the ΔPVF11 mutant-treated seedlings. The complemented mutant, PVF11C, apparently recovered the wild-type virulence. (B) Bar graphs represent the shoot and root lengths as a measure of the bacterial virulence to the seedlings. The different uppercase and lowercase letters on the error bars represent significant differences between shoot and root lengths, respectively, with P < 0.05, according to least significant difference test (LSD). (C) Photographs of rice stems at the vegetative stage showing the typical blight symptoms of infected rice stems. Treatment with the ΔPVF11 mutant resulted in reduced virulence as limited symptomatic lesions were observed, compared to plants infected with wild-type BGR1 or the complemented mutant PVF11C. Red arrows show the spread of symptomatic lesions away from the inoculation sites. (D) Bar graphs showing the bacterial populations in treated stems 8 days after inoculation, expressed as log colony forming units (cfu)/g rice stem. The different letters on the error bars indicate significant differences according to LSD test (P < 0.05). (E) Photographs from the reproductive stage assay on rice panicles showing the typical blight symptoms on the rice grains after treatment with BGR1, ΔPVF11, and PVF11C. (F) Stacked bar graphs representing disease severity distribution pattern on the harvested grains. There was no difference in disease severity between the wild-type, ΔPVF11, and PVF11C mutants. Sterile distilled water was used as negative control in all assays.
Plant Pathol. J. 2019;35:280-6
© 2019 Plant Pathol. J.