Journal of Engineering Science and Technology (Sep 2018)
RESPONSE OF PLANT GROWTH REGULATORS ON THE GROWTH OF DIFFERENT TYPES OF IN VITRO CULTURES OF Pogostemon cablin (Blanco) BENTH FOR PATCHOULI ALCOHOL PRODUCTION
Abstract
Patchouli Alcohol (PA) is one of the major active constituents in Pogostemon cablin (Blanco) Benth plant (P. cablin). The geographical, seasonal and environmental variations contribute to the fluctuation in oil content and quality. The plant cell culture technique has emerged as a substitute method for the production of essential oil. The present study was conducted to investigate the effect of Plant Growth Regulators (PGRs) on the growth and production of PA in vitro plantlets, callus as well as cell suspension cultures of P. cablin. Plantlets of P. cablin were successfully obtained by inoculating leaf explants on Murashige and Skoog (MS) medium augmented with α-Naphthalene Acetic Acid (NAA; 0.1 mg/L) and 6-Benzylaminopurine (BAP; 0.5 mg/L) as shooting hormones. Meanwhile, NAA (0.5 mg/L) was combined with activated charcoal (5 g/L) for rooting hormones. The effects of different types of auxin [Picloram, 2, 4- Dichlorophenoxyacetic acid (2, 4-D) and NAA] were investigated in order to determine the most suitable callus induction and maintenance medium. The best callus induction response was obtained on MS medium supplemented with 3 mg/L picloram in which, a healthy and friable callus was acquired in 21 days of culture. Callus was successfully maintained in MS medium added with a reduced concentration of picloram (1 mg/L). The results on the effect of PGRs in the cell suspension cultures of P. cablin indicated that picloram (1 mg/L) was the best growth hormone in initiating P. cablin cell suspension cultures in the dark condition. A higher dry cell weight (0.50 ± 0.03 g/20 mL) was produced in 15 days compared to the other PGRs used. Quantification of PA using gas chromatography with flame ionization detector confirmed that maximum yield of PA was obtained from the leaves of P. cablin plantlets (61.12 ± 1.39 mg/L), callus cultures (37.39 ± 1.19 mg/L) and cell suspension cultures (34.39 ± 1.26 mg/L). This study shows that picloram was the most suitable PGR for the growth of callus and cell suspension cultures as well as the production of PA.
