Ri-mediated transformation of Artemisia annua with a recombinant farnesyl diphosphate synthase gene for artemisinin production

A transgenic system was developed for Artemisia annua L. via Agrobacterium rhizogenes-mediated transformation. Using this system a cDNA encoding farne syl diphosphate synthase (FDS) placed under a CaMV 35S promoter was transfe rred into Artemisia annua using Agrobacterium rhizogenes strain ATCC15834. Among the 150 hairy root lines established, 16 lines showed resistance to k anamycin (20 mg l(-1)). The intergration of FDS gene was confirmed by PCR a nd Southern blot analysis, and analysis of Northern blot revealed that the foreign FDS gene was expressed at the transcriptional level in three hairy root lines (F-1, F-24 and F-26 root line). F-1, F-24 and F-26 root lines gr ew faster than the control hairy root line. However, on the MS medium growt h of F-26 root line was abnormal in that callus frequently formed. Analysis of artemisinin demonstrated that about 2-3 mg g(-1) DW of artemisinin were then detected in the three root lines, which is about 3-4, times higher th an that in the control hairy roots.