Elicitation Enhanced the Production of Phenolic Compounds and Biological Activities in Hairy Root Cultures of Bitter melon ( Momordica charantia L.)

ABSTRACT Momordica charantia (Cucurbitaceae) is an important vegetable and also medicinal crop which produces the bioactive compounds for various biological activities with potential uses in human health. The present investigation relates to elicitors of jasmonic acid (JA) and salicylic acid (SA) to enhance biomass accumulation and phenolic compound production in hairy root cultures of M. charantia. Hairy root cultures were elicited with JA and SA at 0, 25, 50 and 100 μM concentrations respectively. The adding of elicitation to the hairy root cultures on the 15th day of culture and the roots were harvested on day 25. Cultures supplemented with 100 μM JA and SA enhanced the phenolic compounds significantly compared to that of non-elicited hairy root cultures. The biomass of hairy root culture significantly increased by SA whereas decreased in JA elicitation at 100 μM. JA and SA-elicited hairy root cultures significantly produced a higher amount of phenolic compounds (12811.23 and 11939.37µg/g), total phenolic (4.1 and 3.7 mg/g) and flavonoid (3.5 and 3.2 mg/g) contents than non-elicited hairy root cultures (10964.25 µg/g, 2.8 and 2.5 mg/g). JA and SA-elicited hairy root cultures were significantly higher antioxidant activity of DPPH (84 and 78%), reducing potential (0.53 and 0.48), phosphomolybdenum (3.6 and 3.2 mg/g) and ferrous ion chelating assays (80 and 74%) than non-elicited hairy root cultures. The higher antimicrobial and anticancer activity were exhibited in JA and SA-elicited than non-elicited hairy root cultures. This protocol can be developed for the production of phenolic compounds from JA and SA-elicited hairy root cultures.

Enhancement of camptothecin production in Camptotheca acuminata hairy roots by overexpressing ORCA3 gene.

Being a good anti-tumor drug, camptothecin (CPT) is a kind of modified monoterpene indole alkaloid firstly isolated from the deciduous Chinese happy tree with rapidly increasing clinical demand. Due to the great importance and low content of this compound, it is very important to improve CPT production by modern biotechnology. ORCA3 is a jasmonateresponsive APETALA2-domain transcript factor isolated from Catharanthus roseus, with strong ability to up-regulate expression of serveral key genes involved in TIA biosynthetic pathway. To investigate physiological function of ORCA3 gene in Camptotheca acuminata, the ORCA3 gene was transformed using Agrobacterium-mediated gene transfer technology. PCR analysis confirmed that the ORCA3 gene was integrated into the plant genome. HPLC showed that overexpression of ORCA3 in transgenic hairy root lines can effectively enhance the production of camptothecin with 1.5-fold compared with the control (1.12 mg/g dw). The results revealed that ORCA3 is an effective regulatory gene for improving metabolic flux in camptothecin biosynthetic pathway at the first time.