We have compared properties of roots from different lines (genotypes) of tobacco raised either in tissue culture or grown from seed. The different lines included unmodified plants and plants modified to express reduced activity of the enzyme cinnamoyl-CoA reductase, which has a pivotal role in lignin biosynthesis. The size and structure of the rhizosphere microbial community, characterized by adenosine triphosphate and phospholipid fatty acid analyses, were related to root chemistry (specifically the soluble carbohydrate concentration) and decomposition rate of the roots. The root material from unmodified plants decomposed faster following tissue culture compared with seed culture, and the faster decomposing material had significantly higher soluble carbohydrate concentrations. These observations are linked to the larger microbial biomass and greater diversity of the rhizosphere communities of tissue culture propagated plants.
Bibliographical noteFunding Information:
Acknowledgements We are grateful to the UK Biotechnology and Biological Sciences Research Council for financial support under the Biological Interactions in the Root Environment programme grant nos. BRE 13660 and 13661. We thank Simon Thain for collaboration and Jess Searle for technical assistance.
Copyright 2008 Elsevier B.V., All rights reserved.
- Genetic modification
- In vitro propagation
- Nicotiana tabacum (tobacco)
- Rhizosphere microbial community
- Soluble carbohydrates