Hairy Root Cultures - Opportunities and Key Protocols for Studies in Metabolic Engineering

This chapter provides a brief overview of the molecular biology of hairy root formation. It summarises the value of hairy root cultures as a tissue culture tool for secondary metabolite studies. The history of using hairy roots grown in vitro as an experimental tissue is a comparatively short one. Whilst hairy roots have much to offer for secondary metabolism studies, one possible limitation which should be noted is that they may not produce compounds which are produced in aerial tissues of plants. Stability in synthesis, together with reproducibility between production runs, are essential prerequisites for any commercial production process and are also highly desirable for experimental purposes. Comparative mapping and DNA:DNA hybridisation experiments indicated that all strains have highly conserved “core” DNA which is essential for hairy root formation. There are reports of some cytological variability in hairy root cultures, including variation in ploidy, chromosome number and chromosome structure.