Light and temperature regulated terpene biosynthesis: hepatoprotective monoterpene picroside accumulation in Picrorhiza kurrooa

Abstract

Picrorhiza (Picrorhiza kurrooa) is an endangered medicinal plant with well-known hepatoprotective activity attributed to monoterpenoid picrosides. The present article details on regulatory genes of terpenoid metabolism, 3-hydroxy-3-methylglutaryl coenzyme A reductase (pkhmgr) and 1-deoxy-D-xylulose-5-phosphate synthase (pkdxs) from picrorhiza. Since no molecular information was available, these genes were cloned to full-length by degenerate primers and rapid amplification of cDNA ends, followed by cloning of the upstream sequences that showed the presence of core sequences for light and temperature responsiveness. Electrophoretic mobility shift assay confirmed binding of protein to these motifs. Expression of pkhmgr and pkdxs was up-regulated at 15 degrees C as compared to at 25 degrees C as well as under light as compared to dark conditions. Picrosides content exhibited the trend similar to gene expression. To rule out the possible limitation of carbon pool under dark condition, plantlets of picrorhiza were raised in vitro in Murashige and Skoog medium supplemented with 3% sucrose. Results showed similar up-regulation of both the genes and the higher picrosides content in in vitro raised plantlets in the presence of light. Data suggested the important roles played by light and temperature in regulating pkhmgr and pkdxs, and the picrosides level in picrorhiza.

Mining NGS transcriptomes for miRNAs and dissecting their role in regulating growth, development, and secondary metabolites production in different organs of a medicinal herb, Picrorhiza kurroa

“…Three organs (root, shoot, and stolon) together with their in vitro culture counterparts were chosen for investigation of miRNA expression specific to each condition. Due to wellknown pharmacological relevance of picrosides, several attempts have been made to understand the biosynthesis and accumulation of picrosides in P. kurroa in the past (Kawoosa et al 2010;Sood and Chauhan 2010), however, still the molecular basis of biomass yield and picrosides content is not thoroughly understood in P. kurroa. Therefore, current study was aimed at identification of miRNAs which possibly regulate the biological and physiological processes contributing to biomass yield and metabolites content in different organs of P. kurroa.…”

Characterization and Transcriptional Profiling of Ginkgo biloba Mevalonate Diphosphate Decarboxylase Gene (GbMVD) Promoter Towards Light and Exogenous Hormone Treatments

“…Light is a major environmental signal for the differential accumulation of isoprenoid-derived metabolites during plant growth and development. For example, illumination in Picrorhiza kurroa promotes the synthesis of monoterpene picroside (Kawoosa et al, 2010). This result is concomitant with the light-dependent accumulation of the transcripts of HMGS and DXS, which are key genes in the MVA and MEP pathways, respectively (Kawoosa et al, 2010).…”

Changes in concentration of volatile compounds in response to defoliation of Muscat of Alexandria grapevines grown under a traditional farming system

“…], fruit temperature may reach levels that are detrimental to terpene biosynthesis. Kawoosa et al (2010) reported that genes involved in terpene synthesis can be down-regulated at temperatures above 25 ºC. In this study, daily air temperatures at the fruit zone during veraison (mid-January) were 50% of the time above 30 ºC, which may explain the low concentrations of volatile compounds reported here.…”