Effects of Stay-green Rice Gene (SGR) Over-expression and Mutation on Some Indexes Related with Carbon and Nitrogen Metabolism in Rice Leaves

Abstract:

The effects of Stay-green rice gene (SGR) over-expression and mutation on carbon and nitrogen metabolism in rice (Oryza sativa L.) leaves were studied by using hydroponic culture. The results showed that SGR over-expression reduced contents of soluble protein, chlorophyll and starch, but the contents of soluble sugar and free amino acids increased, as well as the activities of glutamine synthetase (GS) and glutamate synthetase (GOGAT) in rice leaves under normal growth condition. Whereas, SGR mutation increased the contents of starch and soluble protein and improved nitrate reductase (NR) activity. Under nitrogen deficiency, the variation trend of physiological parameters was consistent among the three types of rice except the starch content in SGR mutant rice leaves. These suggested that the changes in SGR level could influence the carbon and nitrogen metabolism in rice leaves.

Key words:Stay-green rice gene (SGR);C/N metabolism;Nitrogen deficiency;Rice