Proceedings of the Botanical Society of Korea Conference (한국식물학회:학술대회논문집)
- 1996.06a
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- Pages.50-63
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- 1996
Cytokinin and Nitrogen-Mediated Gene Regulation for $C_4$ Photosynthesis
- Sugiyama, Tatsuo (Department of Applied Biological Sciences, School of Agricultural Sciences, Nagoya University) ;
- Takei, Kentaroch (Department of Applied Biological Sciences, School of Agricultural Sciences, Nagoya University) ;
- Deji, Atsushi (Department of Applied Biological Sciences, School of Agricultural Sciences, Nagoya University) ;
- Tanguichi, Mitsutaka (Department of Applied Biological Sciences, School of Agricultural Sciences, Nagoya University) ;
- Sakakibara, Hitoshi (Department of Applied Biological Sciences, School of Agricultural Sciences, Nagoya University)
- Published : 1996.06.01
Abstract
Nitrogen (N) is an important regulator of the expression of genes involved in carbon and N assimilation pathways in plants by selectively altering the levels of proteins and/or mRNAs. These in C4 plants include genes for such as phosphoenolpyruvate carboxylase, carbonic anhydrase, and pyruvate-Pi dikinase. The C4 genes are regulated in mesophyll cells by N availability both transcriptionally and posttranscriptionally through cytokinins and glutamine as signals. The level of both the signals is up-regulated by N availability: cytokinins in roots and glutamine in leaves. The level of glutamine is controlled by the differential expression by N of glutamine synthetase and ferrdoxin-dependent glutamate synthase genes which locate in the mesophyll cells of C4 plants. The results is discussed as molecular mechanism for the greater N use efficiency of the plants as well as N partitioning is the photosynthetic cells.
Keywords
- N, nitrogen;
- PEPC;
- phosphoenolpyruvate carboxylase;
- PPDK;
- pyruvate orthophosphate dikinase;
- Rubisco;
- ribulose 1,5-bisphosphate carboxylase/oxygenase;
- GS;
- glutamine synthetase;
- AlaAT;
- alanine aminotransferase;
- AspA T;
- aspartate aminotransferase;
- Fd-GOGAT;
- ferredoxin-dependent glutamate;
- MS X;
- methionine sulfoximine;
- CA;
- carbonic anhydrase