Molecular analysis of the pathogenicity-related polygalacturonase gene pehA of Burkholderia gladioli pv. alliicola isolated from onion(Allium cepae. L)

Abstract The proteoglycanase (PGase) gene secreted of Burkholderia gladioli pv. alliicola was cloned to examine the correlation between the properties of this enzyme gene and pathogenicity. Recombinant clones of about 20 kb that produce PGase were separated from the genomic library of B. alliicola CH1. And it was shown that PGase gene was located within a fragment of about 2.6 kb of ApaI-XhoI restriction enzyme. The pehA gene indicated 79% homogeneity with the phg-A gene produced by Burkholderia cepacia (B. cepacia) plasmid pPEC320. PGase takes a structure in which α-helix connects the outer part of β-barrel with β-sheet, a common characteristic of enzyme structures that decomposes plant cell walls. The pehA gene macerated as if it were gnawing at the onion tissue.