Due to their fast growth rates and biochemical stability, 'hairy root' cult
ures remain unsurpassed as the choice for model root systems and have promi
se as a bioprocessing system. Applications are wide-ranging, from the produ
ction of natural products and foreign proteins to a model for phytoremediat
ion of organic and metal contaminants. Hairy roots will have a continuing r
ole as an experimental model in plant metabolic engineering.