title: Rhizophagus irregularis as an elicitor of rosmarinic acid and antioxidant production by transformed roots of Ocimum basilicum in an in vitro co-culture system.
abstract: Arbuscular mycorrhiza is a symbiotic association formed between plant roots and soil borne fungi that alter and at times improve the production of secondary metabolites. Detailed information is available on mycorrhizal development and its influence on plants grown under various edapho-climatic conditions, however, very little is known about their influence on transformed roots that are rich reserves of secondary metabolites. This raises the question of how mycorrhizal colonization progresses in transformed roots grown in vitro and whether the mycorrhizal fungus presence influences the production of secondary metabolites. To fully understand mycorrhizal ontogenesis and its effect on root morphology, root biomass, total phenolics, rosmarinic acid, caffeic acid and antioxidant production under in vitro conditions, a co-culture was developed between three Agrobacterium rhizogenes-derived, elite-transformed root lines of Ocimum basilicum and Rhizophagus irregularis. We found that mycorrhizal ontogenesis in transformed roots was similar to mycorrhizal roots obtained from an in planta system. Mycorrhizal establishment was also found to be transformed root line-specific. Colonization of transformed roots increased the concentration of rosmarinic acid, caffeic acid and antioxidant production while no effect was observed on root morphological traits and biomass. Enhancement of total phenolics and rosmarinic acid in the three mycorrhizal transformed root lines was found to be transformed root line-specific and age dependent. We reveal the potential of R. irregularis as a biotic elicitor in vitro and propose its incorporation into commercial in vitro secondary metabolite production via transformed roots.
authors.affiliation: TERI-Deakin Nanobiotechnology Centre, The Energy and Resources Institute (TERI), DS Block, India Habitat Centre, Lodhi Road, New Delhi, 110003, India.|Centre for Chemistry and Biotechnology, School of Life and Environmental Sciences, (Waurn Ponds Campus), Deakin University, Geelong, Australia, 75 Pigdons Road, Locked Bag 20000, Geelong, VIC, 3220, Australia.
authors.forename: Shivani
authors.initials: S
authors.lastname: Srivastava
authors.affiliation: Centre for Chemistry and Biotechnology, School of Life and Environmental Sciences, (Waurn Ponds Campus), Deakin University, Geelong, Australia, 75 Pigdons Road, Locked Bag 20000, Geelong, VIC, 3220, Australia.
authors.forename: Xavier A
authors.initials: XA
authors.lastname: Conlan
authors.affiliation: Centre for Chemistry and Biotechnology, School of Life and Environmental Sciences, (Waurn Ponds Campus), Deakin University, Geelong, Australia, 75 Pigdons Road, Locked Bag 20000, Geelong, VIC, 3220, Australia.
authors.forename: David M
authors.initials: DM
authors.lastname: Cahill
authors.affiliation: TERI-Deakin Nanobiotechnology Centre, The Energy and Resources Institute (TERI), DS Block, India Habitat Centre, Lodhi Road, New Delhi, 110003, India. aloka@teri.res.in.
authors.forename: Alok
authors.initials: A
authors.lastname: Adholeya
mesh_terms: D002934:Cinnamates / Q000378:metabolism*; D018920:Coculture Techniques; D053630:Depsides / Q000378:metabolism*; D055137:Glomeromycota / Q000502:physiology* / Q000648:ultrastructure; D008163:Luminescent Measurements; D038821:Mycorrhizae / Q000502:physiology*; D018649:Ocimum basilicum / Q000382:microbiology*; D018517:Plant Roots / Q000378:metabolism* / Q000382:microbiology* / Q000648:ultrastructure; D046509:Tissue Culture Techniques; D000097123:Rosmarinic Acid
chemical_list: D002934:Cinnamates; D053630:Depsides; D000097123:Rosmarinic Acid
keywords: Antioxidants; Elicitor; In vitro; Ocimum basilicum; Rhizophagus irregularis; Rosmarinic acid; Transformed roots