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Related Experiment Video

Updated: Jan 6, 2026

Discrimintion and Mapping of the Primary and Processed Transcripts in Maize Mitochondrion Using a Circular RT-PCR-based Strategy
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Pentatricopeptide repeat protein DEK40 is required for mitochondrial function and kernel development in maize.

Ru Chang Ren1, Xiaoduo Lu2, Ya Jie Zhao1

  • 1State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, Shandong, China.

Journal of Experimental Botany
|October 11, 2019
PubMed
Summary

Maize defective kernel 40 (dek40) mutant reveals a Pentatricopeptide repeat protein essential for mitochondrial RNA editing. This protein

Keywords:
Kernel developmentRNA editingmaizemitochondrionpentatricopeptide repeat protein

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Area of Science:

  • Plant Molecular Biology
  • Mitochondrial Gene Expression
  • Maize Genetics

Background:

  • Pentatricopeptide repeat (PPR) proteins form a large family with many uncharacterized functions.
  • Mitochondrial RNA editing is crucial for proper gene expression and organelle function.

Purpose of the Study:

  • To characterize the function of the maize DEK40 protein, a member of the PPR family.
  • To elucidate the role of DEK40 in mitochondrial RNA editing and its impact on maize kernel development.

Main Methods:

  • Isolation and genetic analysis of the maize dek40 mutant.
  • Positional cloning to identify the DEK40 gene.
  • Mitochondrial localization studies.
  • RNA binding assays for target transcripts (cox3, nad2, nad5).
  • Analysis of RNA editing efficiency.
  • Reactive oxygen species (ROS) detection and programmed cell death assays.
  • RNA sequencing to assess gene expression changes.

Main Results:

  • DEK40 encodes a mitochondrial PPR protein involved in processing specific mitochondrial transcripts (cox3, nad2, nad5).
  • The dek40 mutant exhibits defects in C-to-U RNA editing at specific sites (cox3-314, nad2-26, nad5-1916).
  • Impaired editing leads to mitochondrial dysfunction (complexes I and IV), increased ROS, and programmed cell death in endosperm.
  • Altered gene expression in pathways like glutathione metabolism and starch biosynthesis observed in the mutant.

Conclusions:

  • DEK40 is essential for the C-to-U editing of specific mitochondrial transcripts in maize.
  • Dysfunctional RNA editing by DEK40 disrupts mitochondrial function and impacts kernel development.
  • This study expands the understanding of PPR-E+ protein functions in RNA editing and plant development.