Abstract
Hairy roots (HRs) grown in vitro are a powerful platform for plant biotechnological advances and for the bio-based production of metabolites of interest. In this work, black carrot HRs able to accumulate anthocyanin as major secondary metabolite were used. Biomass and anthocyanin accumulation were improved by modulating growth medium composition—different Murashige & Skoog (MS)-based media—and H2O2-elicitation, and the level of the main antioxidant enzymes on elicited HRs was measured. Higher growth was obtained on liquid 1/2 MS medium supplemented with 60 g/L sucrose for HRs grown over 20 days. In this medium, 200 µM H2O2 applied on day 12 induced anthocyanin accumulation by 20%. The activity of superoxide dismutase (SOD)—which generates H2O2 from O2•−—increased by over 50%, whereas the activity of H2O2-scavenging enzymes was not enhanced. Elicitation in the HRs can result in a controlled oxidative burst, in which SOD activity increased H2O2 levels, whereas anthocyanins, as effective reactive oxygen species scavengers, could be induced to modulate the oxidative burst generated. Moreover, given the proven stability of the HR lines used and their remarkable productivity, this system appears as suitable for elucidating the interplay between antioxidant and secondary metabolism.
Highlights
Infection with the soil-borne pathogenic bacterium Rhizobium rhizogenes causes the proliferation of “hairy roots” (HRs) on a range of dicotyledonous plants [1,2]
The remarkable advantages of Hairy roots (HRs) cultures derived from infected plants include: (1) rapid and high-density growth in hormone-free medium, (2) potentially increased production of secondary metabolites compared to the starting plant material, (3) genotypic stability of the derived HR lines, and (4) simple separation of biomass from the nutrient medium [1,6,7,8,9]
The HR lines used in this study were obtained over five years ago and, during that time, they were maintained via regular sub-culturing without detectable loss of vigour and coloration
Summary
Infection with the soil-borne pathogenic bacterium Rhizobium rhizogenes (formerlyAgrobacterium rhizogenes) causes the proliferation of “hairy roots” (HRs) on a range of dicotyledonous plants [1,2]. The transfer and expression of four loci from the Ri plasmid, commonly referred as rol-genes, play a key role in development of characteristic HRs at the infection site [3,4]. R. rhizogenes rol-genes, the initial transformation steps without the use of recombinant. The remarkable advantages of HRs cultures derived from infected plants include:. (1) rapid and high-density growth in hormone-free medium, (2) potentially increased production of secondary metabolites compared to the starting plant material, (3) genotypic stability of the derived HR lines, and (4) simple separation of biomass from the nutrient medium [1,6,7,8,9]. HR-based production of secondary metabolites is a hotspot in plant biotechnology. Over the last three decades, there has been an increasing body of research related to HR cultures [4]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
