Characterization and Role in the Pathogenesis of Potatoes of a Novel Pectate Lyase from Eriwinia Chrysanthemi 3937

Abstract

Erwinia chrysanthemi 3937 secretes five major isoenzymes of pectate lyase encoded by the pelA, pelB, pelC, pelD, pelE genes. A new isoenzyme of pectate lyase was identified in an Erwinia chrysanthemi mutant deleted of these pel genes. Regulation of pelL transcription in bacterial cells growing in the synthetic medium and in the potato tuber tissue was analysed using gene fusion pel::GUS. As shown for other pel genes, the transcription of pelL is dependent on various environmental conditions. The pelL protein is able to macerate plant tissue. PelL mutant displayed a reduced virulence on potato tubers, demonstrating the important role of this isoenzyme in soft rot disease. Study of pelL gene expression in potato tuber tissue, using fusion of pelL::GUS showed low level of expression of this isoenzyme 24, 48 and 72 hours after inoculation in comparison with other pel (100 times lower than pelB and pelC and 1000 times lower than pelD and pelE). In contrast to other pel, the expression of pelL in tuber tissue achieves its maximum 24 hours inoculation and then decreases.KeywordsPotato TuberTuber TissuePectate LyaseTranscriptional FusionPectin Methyl EsteraseThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.