Recurrent outbreaks of root mat in cucumber and tomato are associated with a monomorphic, cucumopine, Ri-plasmid harboured by various Alphaproteobacteria

S A Weller, D E Stead, J P W Young

Research output: Contribution to journalArticlepeer-review

Abstract

Recurrent outbreaks of root mat have occurred in the UK and France in cucumber and tomato. Root mat is caused by bacterial strains harbouring a Ri-plasmid (pRi). Fifteen root mat-associated (RMA) cucumopine pRi were analysed by PCR-restriction fragment length polymorphism (RFLP) and Southern blotting. These pRi were harboured by Agrobacterium biovar 1 strains isolated during a 1970s outbreak of root mat in UK soil grown cucumber, and also by Agrobacterium biovar 1, Ochrobactrum, Rhizobium and Sinorhizobium isolated during outbreaks of root mat in cucumber and tomato grown hydroponically in the UK and France since 1993. PCR-RFLP analysis of the T-DNA and virD2 regions showed sequence homology between all cucumopine pRi, indicating that these pRi are monomorphic, and thus this pRi remained in the UK without inducing symptoms for some 15 years between outbreaks in the 1970s and 1990s. Cucumopine pRi were also shown to possess the virE2 substitute GALLS gene by Southern blotting. Two other pRi, harboured by Agrobacterium isolated from a recent root mat outbreak in one tomato crop, were also shown to possess the GALLS gene but were shown not to be cucumopine pRi by PCR-RFLP.

Original languageEnglish
Pages (from-to)136-143
Number of pages8
JournalFEMS microbiology letters
Volume258
Issue number1
DOIs
Publication statusPublished - May 2006

Keywords

  • Ti plasmid
  • Alphaproteobacteria
  • mikimopine
  • conjugation
  • hairy root
  • AGROBACTERIUM STRAINS
  • CROWN-GALL
  • RHIZOGENES
  • RHIZOBIUM
  • IDENTIFICATION
  • RADIOBACTER
  • BACTERIA
  • SEQUENCE
  • SOIL
  • PCR

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