Transgenic tomato plant carrying a gene for NADP-dependent glutamate dehydrogenase ( gdhA) from Aspergillus nidulans

Tomato plants were transformed with gene constructs that contained the gdhA gene for NADP-dependent glutamate dehydrogenase from Aspergillus nidulans coupled in the sense orientation with the constitutively active 35S promoter from cauliflower mosaic virus. Four independent transformants, which had one or several copies of the gene in their genomes, were obtained. In these transgenic lines, high-level expression of gdhA mRNA was detected in leaves and fruits, and NADP–GDH activity was detected at high levels in leaves. In the tomatoes from 6 successive weeks after the first flowering, the levels of total free amino acids in transgenic fruits were higher (2- to 3-fold) than that in controls. In particular, the level of glutamate was about twice that in control fruits.