Cloning And Expression Of A Transcription Factor That Regulates The Gene Encoding Farnesyl Diphosphate Synthase From Hevea Brasiliensis

Famesyl diphosphate synthase (FPS), a regulatory enzyme and a rate-limiting factor in natural rubber biosynthesis, catalyses the synthesis of farnesyl diphosphate (FPP), the major substrate used by natural rubber biosynthesis. There is a positive correlativity of the syntheis rate of rubber and concentration of FPP. Therefore, the production of nature rubber may be improved by increasing of FPP in laticifer cell. The expressional regulation of the gene encoding famesyl diphosphate synthase from Hevea brasiliensis remains largely unknown.The promoter of HbFPS was cloned by PCR based on the sequence of HbFPS from Hevea brasiliensis, the bait vector (pFPS-AbA) for yeast one hybrid was constructed. Meanwhile, a cDNA library was constructed by SMART and Advantage technologies. By yeast one hybrid library screening, a transcription factor classified MYC was identified, designated HbMYC3.HbMYC3contained a2,046-bp open reading frame encoding681amino acids, flanking by127bp5UTR and316bp3UTR. The deduced HbMYC3protein, showing high identity to MYC transcription factor of other plant species, was predicted to possess a conserved bHLH domain containing52amino acids at the C-terminus.The expression pattern analysis revealed that HbMYC3had high transcription in bark, and low in latex, flower, embryo and callus. The transcript of HbMYC3in latex was not induced by ethylene or JA.In this study, a transcription factor that regulates the HbFPS gene was cloned by yeast one hybrid library screening. The cloning of HbMYC3gene will enable us to further understanding the molecular mechanism underlying expressional regulation of farnesyl diphosphate synthase from Hevea brasiliensis...