Induction of Hairy Roots from Camptotheca acuminata and the Content of Camptothecin

In order to induce hairy roots from Camptotheca acuminata,we tested different explants(including leaves,steams,cotyledons and hypocotyls),different ages of explants and different strains of Agrobacterium rhizogenes(including A4,15834,R1601 and C58C1).Transgenic roots were confirmed by PCR using rolB specific primers.The results showed that:(1)The appropriate explant was hypocotyls,the most suitable age of hypocotyls was 5～10 d and 15834 was the best one among the four A.rhizogenes strains.(2)The rolB gene from A.rhizogenes was detected in the genome of hairy roots by PCR.(3)CPT as well as 10-hydroxycamptothecin(HCPT) in different hairy roots was detected by HPLC.Hairy roots induced by C58C1 which was the best one among the tested Agrobacterium strains,were able to synthesize 1.219 and 0.305 mg/g of CPT and HCPT,respectively.This work effectively develops a promising approach to produce camptothecin and also provide good basement to metabolize regulation of camptothecin in hairy roots by genetic engineering.