Table 3. Relative X. fastidiosa exoenzyme activity.

Extracellular enzyme a	Wild-type	PD1671 mutant	Complemented PD1671
Carboxymethyl cellulase	1.01 ± 0.20	1.10 ± 0.30	1.20 ± 0.25
Endo-β-1,4-mannanase	0.00 ± 0.00	0.00 ± 0.00	0.00 ± 0.00
Polygalacturonase	0.00 ± 0.00	0.00 ± 0.00	0.00 ± 0.00
Protease	2.12 ± 0.20	2.20 ± 0.30	2.10 ± 0.25

^a Extracellular enzyme activities were estimated from the diameter (mm) of the halo zones of supernatant enzymatic activity surrounding each well. All assays were performed three times, with five replicate plates each. The standard deviations of the means for each enzyme are shown.