FIG 2.

Biofilm formation of Xylella fastidiosa wild-type strains and mutants, as measured by crystal violet staining. Staining of biofilm was performed at the end of the growth curve experiment presented in Fig. 2. Experiments were repeated independently three times. At least 6 wells per plate (and 1 to 3 plates per experiment) were used for each strain. Data were analyzed in SAS 9.3 with PROC GLIMMIX. Error bars indicate standard error of the mean. Different uppercase (WM1-1 and its mutants) or lowercase (TemeculaL and its mutants) letters within each group indicate significant differences at 5% significance level. NA, nonavailable data.