Initially, we sought to introduce all genes into immature
rice embryos (TP 309) stepwise, i.e., singly by particle bombardment,
aiming at subsequently unifying all transgenes into
a single plant by subsequent crossing. However, this approach
was not successful, mainly due to the deleterious integration
pattern frequently produced by this transformation technique,
as revealed by Southern hybridization analysis. Therefore,
Agrobacterium-mediated transformation of precultured rice immature
embryos was used, designed so as to install the entire
-carotene biosynthetic pathway into rice endosperm in a
single transformation effort