Figure 6 : X. fastidiosa lesA mutants are deficient in virulence.

From: The Type II Secreted Lipase/Esterase LesA is a Key Virulence Factor Required for Xylella fastidiosa Pathogenesis in Grapevines

Figure 6

(A) Lipase activity was analyzed around Xff lesA mutant (lesA-) and WT (Tem1) colonies grown in PD3-agar medium supplemented with 1% trybutirin. (B) Esterase activity of proteins from lesA- and WT by 4-methylumbelliferyl butyrate (4-MUB) assay. Esterase activity is diminished significantly in the lesA mutant. (C) Immunoblot detection of LesA in Xff lesA and WT total proteins. The LesA protein was not detected in the mutant, confirming the mutagenesis of the lesA gene. (D) Analysis of biofilm formation in liquid culture, showing the predominance of the biofilm growth mode in lesA when compared to WT. (E) Scanning electron micrographs of Xff culture showing the aggregation of lesA cells typically found in biofilms. (F) Pierce’s disease symptoms in grapevines. Thompson Seedless infected with the wild-type strain Temecula1, the lesA strain, and uninfected (mock inoculated). Data is shown as the difference from uninfected controls (average of 26 plants). Plants inoculated with Xff lesA strain have significantly less PD symptoms (*One-Tailed T-test with Welch’s correction and p value of 0.0351) than Temecula1 infected plants. Pictures were taken by Hossein Gouran.