Effects of rhizodeposition of non-transgenic and transplastomic tobaccos on the soil bacterial community

Lorenzo Brusetti, Aurora Rizzi, Alessandro Abruzzese, Gian Attilio Sacchi, Enzio Ragg, Marco Bazzicalupo, Claudia Sorlini, Daniele Daffonchio*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

6 Scopus citations


The effect of root-released compounds of transplastomic tobacco (Nicotiana tabacum) on the soil bacterial community structure, and their potential to support horizontal gene transfer (HGT) to bacteria have been studied. Soil microcosms were exposed to root-released compounds collected from transplastomic and non-transgenic tobacco cultivars. Cluster analysis of automated ribosomal intergenic spacer analysis (ARISA) profiles of the soil bacterial community after 48 h incubation grouped the transgenic cultivar apart from the non-transgenic, indicating that it had a rhizodeposition pattern different from the parental plants. However, these differences were less than between the two non-transgenic tobacco cultivars studied. NMR characterization of the root-released compounds showed some differences in chemical fingerprinting pattern between the transplastomic and the parental cultivar. However, the effect on bacterial community structure was transient, and tended to disappear after 96 h of incubation. The potential of root-released compounds as a source of transforming DNA for bacteria was investigated by using four potential recipient species. No transformants were obtained following exposure of all the recipients to the root-released compounds. Root-released compounds amended to transgene donor DNA decreased the transformation frequency of Acinetobacter baylyi strain ADP1200, while Azospirillum, Agrobacterium, and Sinorhizobium strains failed to develop competence also in the presence of an external added transgene source. Detection of plastid sequences by PCR suggested that a very low amount of fragmented plastid donor DNA was present in the root-released compounds.

Original languageEnglish (US)
Pages (from-to)11-24
Number of pages14
JournalEnvironmental Biosafety Research
Issue number1
StatePublished - Jan 1 2008


  • Acinetobacter
  • Horizontal gene transfer
  • Root exudate composition
  • Root-released compounds
  • Soil bacterial diversity
  • Transplastomic tobacco

ASJC Scopus subject areas

  • Biotechnology
  • Biomedical Engineering
  • Safety, Risk, Reliability and Quality
  • Environmental Science(all)
  • Agricultural and Biological Sciences(all)
  • Safety Research


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