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Quorum-sensing control and root-exudate mediated induction of rhizobial genes expressed in the rhizosphere

ReferenceBRE13665
Principal Investigator / Supervisor Professor J Downie
Co-Investigators /
Co-Supervisors
Institution John Innes Centre
DepartmentMolecular Microbiology
Funding typeResearch
Value (£) 164,588
StatusCompleted
TypeResearch Grant
Start date 01/10/2001
End date 30/09/2004
Duration36 months

Abstract

Quorum-sensing mutants of Rhizobium leguminosarum appear to have altered cell surface (polysaccharide) characteristics. Adjacent to a quorum-sensing regulatory gene we identified ndvA, which is involved in exporting cyclic glucans and is induced in the rhizosphere. A separate study on protein secretion by R. leguminosarum resulted in the identification of plyB, which encodes an exopolysaccharide lyase; plyB is strongly induced in the rhizosphere and is under quorum-sensing control. Downstream of plyB is ecfP which encodes a sigma factor that clearly belongs to the extracytoplasmic class of 2sigma factors. We propose to characterise the regulation of ndvA, plyB, ecfP (and various other genes involved in surface polysaccharide) with regard to quorum- sensing control and rhizosphere expression. We will identify the rhizosphere factors that induce plyB and ndA expression and a screen for other promoters that are induced in the rhizosphere will be established by DNA sequencing and construction of mutants.

Summary

unavailable
Committee Closed Committee - Plant & Microbial Sciences (PMS)
Research TopicsX – not assigned to a current Research Topic
Research PriorityX – Research Priority information not available
Research Initiative Biological Interactions in the Root Environment (BRE) [2000]
Funding SchemeX – not Funded via a specific Funding Scheme
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