Stimulation of Secondary Metabolites and γ-Terpinene Synthase by Silver Nanoparticles in Callus Cultures of Carum carvi.

Abstract

Biotechnology and nanotechnology are important tools for understanding biochemical pathways. They can be used efficiently for stimulating and increasing the production of secondary metabolites in medicinal plants. The present study aimed to identify the γ-terpinene synthase gene (CcTPS2) as an effective contributor to the biosynthetic pathway of monoterpenes. The effects of silver nanoparticles (AgNPs; 50 and 100mg l- 1) and time (24 and 48h) were examined on secondary metabolites in cell suspension cultures of Carum carvi. This involved the identification, isolation, and sequencing of a partial sequence in the CcTPS2 gene of C. carvi. The genomic sequence of CcTPS2 comprised 292bp which were organized into two exons (110 and 82bp) and one intron (100bp), while the cDNA was 192bp. In the scale of nucleotides, the CcTPS2 gene showed 96% similarity with the TPS2 gene of Oliveria decumbens. We generated sequence data of the CcTPS2 gene for the first time in this species, thereby enabling further developments in understanding the molecular mechanisms responsible for terpene biosynthesis and other chemical derivatives in C. carvi. The results of GC/MS and GC/FID showed that AgNPs strongly affected the secondary metabolites in cell suspension cultures of C. carvi. According to the results, the AgNPs (50mg l- 1) increased p-cymene and carvone contents in comparison with the control. The exposure of plants to 100mg l- 1 AgNPs induced the production of thymol and carvacrol. The results of real-time PCR revealed that the exposure of plants to 100mg l- 1 AgNPs caused a significant upregulation of CcTPS2 expression for 24h. These cell suspension cultures were elicited by AgNPs, the application of which proved as an effective method to improve the production of secondary metabolites in vitro.