EFFICIENT TRANSFORMATION OF RICE (ORYZA-SATIVA L) MEDIATED BY AGROBACTERIUM AND SEQUENCE-ANALYSIS OF THE BOUNDARIES OF THE T-DNA

A large number of morphologically normal, fertile, transgenic rice pla nts were obtained by co-cultivation of rice tissues with Agrobacterium tumefaciens. The efficiency of transformation was similar to that obt ained by the methods used routinely for transformation of dicotyledons with the bacterium. Stable integration, expression and inheritance of transgenes were demonstrated by molecular and genetic analysis of tra nsformants in the R(0), R(1) and R(2) generations. Sequence analysis r evealed that the boundaries of the T-DNA in transgenic rice plants wer e essentially identical to those in transgenic dicotyledons. Calli ind uced from scutella were very good starting materials. A strain of A. t umefaciens that carried a so-called 'super-binary' vector gave especia lly high frequencies of transformation of various cultivars of japonic a rice that included Koshihikari, which normally shows poor responses in tissue culture.