Phenotypic and genotypic relationship between tabtoxin production and pathogenicity in Pseudomonas syringae pv. tabaci strain PTBR2.024

Pseudomonas syringae pv. tabaci strain PTBR2.024 produces tabtoxin and causes wildfire disease on tobacco and green bean. PTBR7.000, a Tn5 mutant of PTBR2.024, does not produce tabtoxin, is nonpathogenic on tobacco and is prototrophic. A 3-kb fragment from a genomic library of the parent strain PTBR2.024 complemented both mutant phenotypes. This 3-kb fragment contains two open reading frames (ORF), ORF1 and ORF2, and two truncated ORFs, ORF3 and ORF4. The Tn5 insert in PTBR7.000 was mapped to ORF2, and complementation studies showed that an intact ORF2 was sufficient to restore tabtoxin production and pathogenicity. The deduced amino acid sequences of ORF2 and truncated ORF3 contain significant homology to bacterial lysine biosynthetic enzymes, diaminopimelate decarboxylase and $\Delta\sp1$-piperidine-2,6-dicarboxylate succinyl transferase, respectively. ORF2, however, is not required for lysine biosynthesis. We designated the sequence corresponding to ORF2 as gene tabA and propose that the product of tabA is an enzyme in the tabtoxin biosynthetic pathway that recognizes a substrate analogue of a compound in the lysine biosynthetic pathway.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Plant Pathology

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2011

Author dc:creator

• Engst, Karen

Contributors dc:contributor

• Shaw, Paul D.

• Biology, Molecular
• Agriculture, Plant Pathology

Statement dc:rights

• Copyright 1992 Engst, Karen

Language dc:language

eng

Identifier

AAI9305517
(UMI)AAI9305517

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/18968