Characterization Of Hyper Virulent Rsmk- Mutant Of Pectobacterium carotovorum

Urmila Adhikari, Tennessee State University


Soft rot is a broad host-range bacterial disease that affects over 80 different cultivated plant species from nearly all plant families. The major causal agents of the disease are bacteria in the soft rot Enterobacteriaceae group including Pectobacterium and Dickeya genera. The major virulence factors of soft rot bacteria are exo-proteins including pectate lyase (Pel), polygalacturonase (Peh), cellulose (Cel), protease (Prt) and effector of type III secretion, Harpin. The production of these factors is regulated by a complex network of positive and negative regulators and environmental signals of both bacterial and host origin. We used a transposon mini-Tn5lacZ to isolate mutant of P. carotovorum that are altered in enzyme production. The mutant A17 overproduces Pel, Cel, Prt and Peh more than its parent, KD100. The transposon and the flanking genomic sequences were cloned into the cosmid vector, pLAFR5 to obtain pA17. The truncated gene in this mutant was designated rsmK [rsm = regulator of secondary metabolism]. The phenotype of the mutants indicates that rsmK is a negative regulator of enzyme production in P. carotovorum.

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Recommended Citation

Urmila Adhikari, "Characterization Of Hyper Virulent Rsmk- Mutant Of Pectobacterium carotovorum" (2015). ETD Collection for Tennessee State University. Paper AAI1599437.