Analysis of the transgenic tobacco plants expressing Panicum miliaceum aspartate aminotransferase genes

Expression of Panicum miliaceum L. (proso millet) mitochondrial and cytosol ic aspartate aminotransferase (mAspAT and cAspAT, respectively) genes in tr ansgenic tobacco plants (Nicotiana tabacum) and their influences on protein synthesis were examined. The mAspAT- or cAspAT-transformed plants had abou t threefold or 3.5-fold higher AspAT activity in the leaf than non-transfor med plants, respectively. Interestingly, the leaves of both transformed pla nts had increased levels of phosphoenolpyruvate carboxylase (PEPC) and tran sformed plants with cAspAT also had increased levels of mAspAT in the leaf. These results suggest that the increased expression of Panicum cAspAT in t ransgenic tobacco enhances the expression of its endogenous mAspAT and PEPC , and the increased expression of Panicum mAspAT enhances the expression of its endogenous PEPC.