Reverse Transcription-PCR analysis of geranylgeranyl diphosphate synthase (JcGGPPS) in Jatropha curcas L. and in silico analysis of Casbene Synthase (JcCS) among Euphorbiaceae

Recently, Euphorbiaceae have attracted much attention for their potential uses in biodiesel production. Their seeds have been well known as the principal resource for oil production. The seed-derived oil content ranged from 28 % to 39 % by dry weight for all Euphorbiaceae species. Meanwhile, their seed also possesses relatively high protein content, ranged from 22 % to 35 %, making them a new alternative for livestock animal feed resources. Nevertheless, the development of this new animal feed resource is limited to the toxicity of the seeds. Its toxicity is mainly caused by the presence of anti-nutrient agents and toxins, such as curcin, trypsin inhibitor and phorbol ester (PE). The later is known to be tetracyclic diterpenes, which represents the primary toxic substances in one of the Euphorbiaceae plants, Jatropha curcas L. To date, little is known about the biosynthesis of these toxic substances. This research aims to analyze the expression of JcGGPPS gene encoding the geranylgeranyl diphosphate synthase involved in the production of the primary precursor for diterpenoid substances. In addition, the phylogram was presented to show the Euphorbiaceae Casbene Synthase (CS). The RT-PCR analysis showed that JcGGPPS is expressed both in seeds and leaves of J. curcas. Meanwhile, in silico analysis of six Euphorbiaceae species showed that CS from Euphorbia esula, Euphorbia resinifera, Euphorbia peplus and Euphorbia fischeriana are highly identical. In addition, CS from J. curcas derives from a different origin than other Euphorbiaceae plants.