Fig. 1. Leaf-surface bacterial growth and canker system development in citrus leaves spray-inoculated with Xcc.

Leaves of plants from Citron C-05 and sweet orange (and four other biotypes, Supplementary Fig. S1) were sprayed with ~ 10⁸ cfu/ml eGFP-Xcc on the abaxial surface of fully expanded young leaves of six citrus biotypes. The inoculated leaves were subjected to confocal imaging for the observation of Xcc growth and the visual assessment of disease symptoms. These experiments were repeated at least three times with similar results. a Representative images showing the growth of Xcc on the leaf surface of sweet orange and Citron C-05 at the indicated time points. b Representative leaves (sections) showing the canker disease symptoms of the six indicated biotypes at 10 dpi. c Quantification of Xcc growth in the inoculated leaves of the six indicated citrus biotypes over a time course