Complementation of an X. campestris pv. campestris exbD2 mutant by a constitutively expressed pglI gene from X. campestris pv. campestris 8004. When compared to the X. campestris pv. campestris wild-type strain B100, it becomes obvious that the mutant strain defective in exbD2, B100-11.03, which had been demonstrated before to induce no symptoms like necrotic lesions , could be functionally complemented with a constitutively expressed pglI gene on plasmid pHGW267 that was integrated into the chromosome. (A) The complemented mutant strain regained its pectate lyase activity, although not to the full extent of the wild-type strain. (B) This correlates well with the reconstituted but attenuated hypersensitive response that this complemented mutant evoked on C. annuum.