A biolistic particle gun was used to deliver genetic material into int
act yam cells. Cultured suspension cells of D. alata were bombarded wi
th microprojectiles coated with pBI221.2 DNA and histochemical assays
were carried out to show transient GUS expression in bombarded cells.
Stably transformed D. alata cells were recovered from cultured cells a
fter bombardment with microprojectiles coated with pRT99gus harbouring
both the nptII and uidA genes. Bombarded cells were selected on a med
ium containing geneticin (G418). Two months after bombardment, calli r
esistant to G418 were assayed for GUS expression. There was a 100% cor
relation between resistance to G418 and GUS expression. From these cal
li, four cell lines were established and GUS activity in each line was
determined fluorometrically. The use of a specific GUS inhibitor show
ed that the GUS activity was due to the introduced uidA gene rather th
an to any intrinsic GUS-like activity originating from the plant. Inco
rporation of the introduced DNA into the plant genomic DNA was confirm
ed by Southern analysis.