This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Schmidt-Eisenlohr, H. Articles by Baron, C. Search for Related Content PubMed PubMed Citation Articles by Schmidt-Eisenlohr, H. Articles by Baron, C. Agricola Articles by Schmidt-Eisenlohr, H. Articles by Baron, C.

The Competitiveness of Pseudomonas chlororaphis Carrying pJP4 Is Reduced in the Arabidopsis thaliana Rhizosphere

Bereich Mikrobiologie, Department Biologie I, Ludwig-Maximilians-Universität München, D-80638 Munich, Germany,¹ Department of Biology, McMaster University, Hamilton, Ontario LS8 4K1, Canada²

Received 1 July 2002/ Accepted 5 December 2002

The effect of the large catabolic IncP plasmid pJP4 on the competitiveness of Pseudomonas chlororaphis SPR044 and on its derivatives SPR244 (GacS deficient), SPR344 (phenazine-1-carboxamide overproducer), and SPR644 (phenazine-1-carboxamide deficient) in the Arabidopsis thaliana rhizosphere was assessed. Solitary rhizosphere colonization by the wild type, SPR244, and SPR644 was not affected by the plasmid. The size of the population of SPR344 carrying pJP4, however, was significantly reduced compared to the size of the population of the plasmid-free derivative. The abiotic stress caused by phenazine-1-carboxamide overproduction probably resulted in a selective disadvantage for cells carrying pJP4. Next, the effect of biotic stress caused by coinoculation of other bacteria was analyzed. Cells carrying pJP4 had a selective disadvantage compared to plasmid-free cells in the presence of the efficient colonizer Pseudomonas fluorescens WCS417r. This effect was not observed after coinoculation with a variety of other bacteria, and it was independent of quorum sensing and phenazine-1-carboxamide production. Thus, the presence of large catabolic plasmids imposes a detectable metabolic burden in the presence of biotic stress. Plasmid transfer in the A. thaliana rhizosphere from P. chlororaphis and its derivatives to Ralstonia eutropha was determined by using culture-dependent and culture-independent techniques. With the cultivation-independent technique we detected a significantly higher portion of exconjugants, but pJP4 transfer was independent of the quorum-sensing system and of phenazine-1-carboxamide production.

This article has been cited by other articles:

• Schmidt-Eisenlohr, H., Gast, A., Baron, C. (2003). Inactivation of gacS Does Not Affect the Competitiveness of Pseudomonas chlororaphis in the Arabidopsis thaliana Rhizosphere. Appl. Environ. Microbiol. 69: 1817-1826 [Abstract] [Full Text]