Enhanced rosmarinic acid biosynthesis in Solenostemon scutellarioides culture: a precursor-feeding strategy

Abstract

The aim of this study was to employ precursor-feeding strategy for the improved production of rosmarinic acid (RA) in Solenostemon scutellarioides in vitro. The cultures were fed with precursors, namely l-phenylalanine (Phe), l-tyrosine (Tyr) and cucumber juice (CJ), at different concentrations. Phe (100 mg L^− 1) and Tyr (400 mg L^− 1) caused ∼1.5- and 2.1-fold increase in RA accumulation within 48 h. CJ (50 mg L^− 1) feeding displayed highest RA content (∼1.6-fold) in 72 h. In this study, we focused on the function of individual precursor on key enzymes involved in RA biosynthesis. The phenylalanine ammonia lyase activity was significantly upregulated after Phe (100 mg L^− 1) feeding, while tyrosine aminotransferase and hydroxyphenylpyruvate reductase activities were improved with Tyr (400 mg L^− 1) treatment. However, rosmarinic acid synthase activity was significantly enhanced by all three precursors. In synergy study, Phe (100 mg L^− 1) + Tyr (400 mg L^− 1) could enhance (∼3.1-fold) RA biosynthesis within 48 h.

Keywords::

• rosmarinic acid
• Solenostemon scutellarioides
• precursors
• biosynthetic enzymes

Acknowledgements

Authors are also grateful to Jadavpur University, Kolkata, India for providing necessary facilities for this study. Authors also would like to acknowledge the Indian Council for Cultural Relation, Kolkata for awarding ICCR fellowship, 2010 to Ms Urmi Das [Ref. No. DAC/EDU/11/03/2012]. The financial support of the University Grants Commission, New Delhi, India is gratefully acknowledged through UGC Rajiv Gandhi National Fellowship, 2010 to Dr Ranabir Sahu [Ref. no. F. 14-2(ST)/2010 (SA-III)]. The authors would like to thank the reviewers for their time and valuable comments.