Biochemical and Molecular Studies on Differential Production of Piperine and its Precursors in Different Parts of Piper Longum L

Abstract

Piper longum (Pipali; Piperaceae) is an important medicinal plant valued for its pungent alkaloids, especially piperine. Despite its importance, the mechanism of piperine biosynthesis is still poorly understood. In the present study, differential production of piperine and its precursors (lysine, cadaverine and piperidine) in different parts of Piper longum plant at various developmental stages and comparative transcriptome analysis of its leaves and spike using Next Generation Sequencing were investigated. The comparative quantitative analysis of Lysine, Cadaverine, Piperideine and Piperine in various parts of Piper longum plant during three developmental stages (Pre-spike, Spike and Post-spike stages) were evaluated.The amount of lysine, cadaverine, piperideine and finally piperine at all developmental stages was found to be pesent in sufficient quantities in root. Piperidine concentration in roots and spike was estimated to be 148.68 and 201.89 µg/mg in spike stage respectively. However, highest concentration of piperine 76.34 (µg/mg) was reported in spike of the plant, while roots had 46.21 (µg/mg) at Pre-spike stage. The Next Generation Sequencing (NGS) for P. longum leaves and spikes was performed using Illumina platform which resulted in generation of high quality data of total 6 GB of raw nucleotide sequencing. Comparative analysis showed 1052 and 2058 genes were significantly up-regulated and down regulated respectively for the sample leaf vs. spike. In de novo assembly of P. longum, 110243 numbers of transcript scaffolds were analyzed. Analysis of transcriptome data from leaf and spike showed gene families that were involved in the biosynthetic pathway of piperine and other secondary metabolites. To validate differential expression of the identified genes, 27 genes were randomly selected to confirm the expression level by (qRT-PCR) based on the up regulation and down regulation of differentially expressed genes obtained through comparative transcriptome analysis of leaves and spike of P. longum. With the help of UniProt database the function of all characterized genes were evaluated. The valuable genetic resource in P. longum would provide the foundation for future genetic and functional genomic research on P. longum or closely related species. The information on differentially regulated genes would be helpful in understanding piperine biosynthesis and its pathway. newline