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A Fluorescence Microscopy Assay for Monitoring Mitophagy in the Yeast Saccharomyces cerevisiae
Published on: July 18, 2011
Expression of a mitochondrial gene orfH79 from the CMS-HongLian rice inhibits Saccharomyces cerevisiae growth and
Xiaojue Peng1, Fanhui Li, Shaoqing Li
1Key Laboratory of MOE for Plant Developmental Biology, College of Life Sciences, Wuhan University, Wuhan, Hubei, 430072, China.
Abstract:
Cytoplasmic male sterility (CMS) has often been associated with abnormal mitochondrial open reading frames (ORF), orfH79 is a mitochondria chimeric gene being responsible for the CMS trait in Honglian (HL) rice. Weakly expressed ORFH79 strongly inhibits the growth of yeast cells. In addition, the content of reactive oxygen species (ROS) in the transformants that expressed ORFH79 was increased by 31%, and ATP was decreased by 41% compared with the control. These results showed ORFH79 peptide is toxic to yeast cells.
Insights
The Honglian rice orfH79 gene, linked to cytoplasmic male sterility (CMS), significantly harms yeast cell growth. This toxic peptide increases reactive oxygen species and reduces ATP, confirming its detrimental effects.
Area of Science:
- Plant genetics
- Molecular biology
- Mitochondrial genetics
Background:
- Cytoplasmic male sterility (CMS) in rice is often linked to aberrant mitochondrial open reading frames (ORFs).
- The orfH79 gene in Honglian (HL) rice is a mitochondrial chimeric gene responsible for the CMS trait.
- Understanding the function and impact of these mitochondrial ORFs is crucial for crop improvement.
Purpose of the Study:
- To investigate the functional impact of the orfH79 gene product on cellular physiology.
- To determine the toxicity of the ORFH79 peptide in a heterologous system (yeast).
- To elucidate the cellular mechanisms underlying the observed toxicity.
Main Methods:
- Gene expression analysis of orfH79 in yeast.
- Cell growth assays to assess growth inhibition.
- Measurement of reactive oxygen species (ROS) levels.
- Assessment of cellular adenosine triphosphate (ATP) content.
Main Results:
- Weak expression of ORFH79 significantly inhibited yeast cell growth.
- Transformed yeast cells showed a 31% increase in ROS content.
- ATP levels in transformants decreased by 41% compared to control cells.
- These findings indicate that the ORFH79 peptide is toxic to yeast cells.
Conclusions:
- The mitochondrial chimeric gene orfH79 is responsible for the cytoplasmic male sterility trait in Honglian rice.
- The ORFH79 peptide exhibits toxicity in yeast, evidenced by growth inhibition, increased ROS, and decreased ATP.
- This study provides insights into the molecular mechanisms of CMS and the cellular toxicity of specific mitochondrial ORFs.
