Expression of a methionine-rich storage albumin from the Brazil nut (Bertholletia excelsa HBK, Lecythidaceae) in transgenic bean plants (Phaseolus vulgaris L., Fabaceae)

Bean (Phaseolus vulgaris), an important component in the diet of people in developing countries, has low levels of the essential amino acid, methionine. We have attempted to correct this deficiency by introducing a transgene coding for a methionine-rich storage albumin from the Brazil nut via biolistic methods. The transgene's coding sequence was driven by a doubled 35S CaMV promoter and AMV enhancer sequences. The transgene was stable and correctly expressed in homozygous R-2 to R-5 seeds. In two of the five transgenic lines the methionine content was significantly increased (14 and 23%) over the values found in untransformed plants.