Regulation of C4 Gene Expression in Developing Amaranth Leaves
J. L. Wang1, D. F. Klessig, J. O. Berry
1Department of Biological Sciences, State University of New York at Buffalo, Buffalo, New York 14260.
The Plant Cell
|February 1, 1992
Summary
Gene expression for key C4 photosynthesis enzymes in amaranth leaves was studied. Ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBPCase) and pyruvate orthophosphate dikinase showed distinct developmental patterns, while phosphoenolpyruvate carboxylase regulation appeared complex.
Area of Science:
- Plant Biology
- Biochemistry
- Molecular Biology
Background:
- C4 photosynthesis is a complex trait involving specialized leaf anatomy and enzyme localization.
- Understanding the genetic regulation of C4 enzymes is crucial for improving crop efficiency.
Purpose of the Study:
- To investigate the spatiotemporal expression patterns of genes encoding key C4 photosynthetic enzymes during early leaf development in amaranth.
- To elucidate the regulatory mechanisms controlling the cell-specific expression of these enzymes.
Main Methods:
- Immunofluorescence microscopy and in situ hybridization were employed to detect protein and mRNA localization.
- Antibodies against specific enzymes and gene probes were used to analyze expression patterns.
Main Results:
- Ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBPCase) genes initially showed a C3-like expression pattern, later becoming localized to bundle sheath cells, characteristic of C4 plants.
- Pyruvate orthophosphate dikinase genes were consistently expressed in mesophyll cells.
- Phosphoenolpyruvate carboxylase (PEPCase) protein was found only in mesophyll cells, despite homologous RNA sequences in both mesophyll and bundle sheath cells, suggesting complex regulation.
Conclusions:
- Cell-specific expression of RuBPCase is largely regulated at the transcript accumulation level.
- PEPCase gene regulation in amaranth is complex, potentially involving differential gene expression or post-transcriptional control.
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