Water potential is maintained during water deficit in Nicotiana tabacum expressing the Escherichia coli glutamate dehydrogenase gene

Expression of bacterial gdhA (glutamate dehydrogenase; GDH; E.C. 1.4.1.1) genes in transgenic plants fundamentally alters plant growth, herbicide tolerance and metabolite profiles. The aim was to correlate gdhA expression with water potential during deficit using transgenic Nicotiana tabacum cv. 'SR1' (tobacco). Expression of GDH activity from the transgene was significantly correlated with high water potentials during deficit, both after 5 days of water deprivation (R = 0.91) and after 6 h after re-watering on day 6 (R = 0.72). GDH expression may provide a tool to alter the response of plants to periodic water deficit.