Gene-transfer by cocultivation of mature embryos with Agrobacterium tumefaciens - application to cowpea (Vigna unguiculata walp)

Our studies have shown for the first time that chimeric transgenic cowpea plants could be produced from mature embryos cocultivated with Agrobacterium tumefaciens. Pilot studies demonstrated the possibility of obtaining transgenic cowpea callus cells following cocultivation of excised mature embryos with oncogenic hypervirulent Agrobacterium tumefaciens A281 (pTiBo542/pGA472). Subsequently, cowpea plants chimeric for a gus transgene were obtained by cocultivating mature embryos excised from ungerminated seeds with disarmed A. tumefaciens C58 (pGV2260/p35SGUSINT) carrying a plant-expressable gus gene interrupted by an intron. Studies of reporter transgene expression showed that transformed cells were mostly located in the subepidermal regions of the plant stems.