Screening Of Transporters Involved In Regulating Monoterpenoid Indole Alkaloids Production In Catharanthus Roseus

Catharanthus roseus is extensively investigated as a model medicinal plant for its diverse monoterpenoid indole alkaloids(MIAs)biosynthesis.Many of these MIAs have been demonstrated for their ecological and pharmaceutical functions,including two dimeric MIAs,vinblastine and vincristine,which are widely used as anti-cancer drugs for clinical therapy.Due to their complicated chemical structures,it's not feasible to produce these compounds by chemical synthesis and most of vinblastine and vincristine are obtained from plant extracts.Therefore,many investigations on regulation of MIAs biosynthesis were carried out for possible promoting MIAs production in C.roseus,which is the only plant source for the extraction of vinblastine and vincristine.In this work,co-expression analysis was previously applied to screen possible transporter genes in C.roseus,which could be involved MIAs biosynthesis using transcriptome database created from plant materials with different developmental stages,tissues and different cell types.Pathway genes involved in MIAs biosynthesis in C.roseus were selected as “bait genes” to identify co-expressed candidate transporter genes.Through co-expression analysis,eight transporter genes,CrTP1,CrTP2,CrTP3,CrTP4,CrTP5,CrTP6,CrTP7 and CrTP8 were identified for further analysis in this work.Detection of the accumulation levels of catharanthine and vindoline revealed that vindoline was accumulated at relative high level in CrTP2-VIGS leaves compared to that in EV-VIGS control leaves;Catharanthine was accumulated at relative low levels in CrTP3-VIGS and CrTP6-VIGS leaves compared to that in EV-VIGS control leaves;Catharanthine was accumulated at relative high level in CrTP4-VIGS leaves compared to that in EV-VIGS control leaves;Vindoline was accumulated at relative low level in CrTP5-VIGS leaves compared to that in EV-VIGS control leaves.Our results show that CrTP2,CrTP3,CrTP4,CrTP5 and CrTP6 could be involved in MIAs biosynthesis in C.roseus.