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Updated: Oct 2, 2025
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Discrimintion and Mapping of the Primary and Processed Transcripts in Maize Mitochondrion Using a Circular RT-PCR-based Strategy
Published on: July 29, 2019
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Pentatricopeptide repeat protein CNS1 regulates maize mitochondrial complex III assembly and seed development
Shuai Ma1, Wenzhu Yang1, Xiaoqing Liu1
1Crop Functional Genome Research Center, Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
Plant Physiology
|February 26, 2022
Summary
Maize (Zea mays) cytochrome c maturation FN stabilizer1 (CNS1) is crucial for maintaining the integrity of mitochondrial RNA. This pentatricopeptide repeat protein ensures proper gene expression for seed development.
Area of Science:
- Plant molecular biology
- Mitochondrial genetics
- Organelle biogenesis
Background:
- Mitochondrial function depends on nuclear and mitochondrial gene products for electron transport chain complex assembly.
- Pentatricopeptide repeat (PPR) proteins are involved in organelle RNA metabolism, with some stabilizing RNA 3'-ends.
- The role of PPR proteins in stabilizing the 5'-terminus of mitochondrial RNA is not well understood.
Purpose of the Study:
- To investigate the function of maize cytochrome c maturation FN stabilizer1 (CNS1), a nuclear-encoded PPR protein.
- To determine the role of CNS1 in mitochondrial RNA stability and its impact on maize seed development.
Main Methods:
- Cloning and characterization of the maize CNS1 gene.
- Analysis of cns1 mutant phenotypes, including kernel development and mitochondrial gene transcripts.
- Biochemical and molecular assays to identify CNS1 binding sites and localization.
Main Results:
- cns1 mutants showed arrested embryo and endosperm development.
- Mitochondrial transcripts in cns1 mutants were predominantly 5'-truncated, lacking start codons.
- CNS1, a mitochondrial-localized PPR protein, binds to the 5'-UTR of ccmFN transcripts, maintaining their integrity.
- Mutants displayed abnormal mitochondrial morphology and increased alternative oxidase gene expression.
Conclusions:
- CNS1 is essential for maintaining the 5'-integrity of mitochondrial ccmFN transcripts.
- Proper transcript integrity is vital for mitochondrial complex III function, biogenesis, and maize seed development.
- CNS1 represents a novel mechanism for stabilizing the 5'-terminus of mitochondrial RNAs in plants.
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