Hairy roots: Production of metabolites to environmental restoration

Abstract

Hairy roots (HRs) have been proven as a potential source of secondary metabolites and also, for the biotransformation of desirable metabolites. Recently, HRs have emerged as an efficient in vitro model systems for screening the capabilities of different plant species to tolerate, accumulate, and/or to remove environmental pollutants. HRs offer benefits of greater genotypic and phenotypic stability than the dedifferentiated cultures, thus providing a more reliable and a reproducible experimental system, and even for flexibility of insertion of gene of interest to the HR gene construct for efficient applications. Additionally, absence of soil matrix and microbes is the key advantage in HRs for precise removal of toxic products as well as for elucidating metabolic pathways for conversion of hazardous chemicals to non hazardous products. The feasibility of scale up of HRs in bioreactors offers an attractive avenue for industrial processes both for metabolite synthesis as well as for phytoremediation. The present review highlights current knowledge, recent progress, areas which need to be explored and future perspectives related to the application and improvement of the efficiency of HRs for phytoremediation research.