Abstract

Comparative utilization of exogenously supplied carbon substrates as ¹⁴C-saccharose and ¹⁴C-acetate were analyzed for incorporation and accumulation into total triterpenoids saponins. Simultaneously, the metabolic status of the plant was determined by profiling assimilates into primary metabolic pool as sugars, amino acids and organic acids into shoots and roots of Centella asiatica. ¹⁴C-saccharose was preferentially utilized for accumulation of total triterpenoids into shoots- as determined by high ¹⁴C content- compared to when ¹⁴C-acetate was supplied. The content of ¹⁴C label in metabolites in shoots as sugars, amino acids and organic acids was higher when saccharose was supplied as compared to acetate supply. Shoot to root partitioning of metabolites indicates higher ¹⁴C content in sugars and organic acids in roots when ¹⁴C-saccharose was supplied. The relative higher incorporation of ¹⁴C-saccharose indicates the preferential utilization of metabolites from DOXP/terpenoid pathway that contribute to total triterpenoids accumulation.

Key words: ¹⁴C assimilation, primary metabolites, total triterpenoids, Centella asiatica.