The co-expression of Dof1 transcription factor and cytosolic glutamine synthetase gene from Arabidopsis in tobacco largely enhanced plant growth under lower nitrogen

抄録

It is reported that overexpression of cytosolic glutamine synthetase (GS1) from pea enhanced the growth of transgenic tobacco. We also showed that overexpression of Dof1 from Arabidopsis into tobacco moderately improved plant growth under lower nitrogen. To exam if the co-expression of both Dof1 and GS1 genes into tobacco will coordinately increase plant growth or not under normal conditions, we introduced GS1 from Arabidopsis into transgenic tobacco overexpressing Dof1. The over-expression of GS1 and Dof1 was confirmed by RT-PCR analyses. The double transgenic tobacco was grown under strong light and supplied with lower nitrogen nutrition. We observed that the growth of double transgenic tobacco was largely increased and flowered very earlier as compared with control and transgenic tobacco singly overexpressing Dof1. The intermediates related to carbon and nitrogen metabolism in the transgenic tobacco were also analyzed for revealing the effects of the co-expression of Dof1 and GS1 on transgenic tobacco.