What is it about?
Mitochondria, the ‘powerhouse’ in plant cells, provide the main energy source. Meanwhile, damaged mitochondria are detrimental and might lead to cell death if they are not removed timely. In recent years, it has been reported that selective degradation of mitochondria via autophagy, which coined as mitophagy, plays an important role in mitochondria quality control. In a general model, during mitophagy, a cup-like precursor membrane fragment (also known as phagophore or isolation membrane) grows along the mitochondrion and bends into a spherical double-membrane structure named as the autophagosome. In this new study, we have uncovered the key players for plant piecemeal mitophagy, and illustrated how mitochondrial fission event contributes to facilitate the piecemeal eating process. By characterizing the key molecular complex in plant mitochondrial fission process, we demonstrated that dysfunction in the plant-specific mitochondrial fission factor ELM1 significantly delays piecemeal mitophagy and leads to the accumulation of megamitochondria sequestered by multiple phagophore precursors. More importantly, mutations in these key players suppress mitochondrial protein degradation, making plants less tolerance to heat stress.
Featured Image
Photo by Brooke Lark on Unsplash
Why is it important?
The research findings underscore the importance of mitochondrial fission machinery in heat-induced piecemeal mitophagy across evolutionarily diverse organisms, providing valuable insights into mitophagosome biogenesis for plant stress resilience. As such, future investigation into the detail molecular mechanism can provide new solutions to help mitigate the effect of climate change on crop production.
Perspectives
There is a long debate that whether mitochondrial fission is required for mitophagy. Plant mitochondria display a unique pattern, but they also have to reorganize and reshape membranes to help cells to survive under changeable and stress conditions. We suspect that beside mitochondria, turnover of other cellular structures might also be governed by piecemeal autophagy. It will be exciting to further investigate the molecular mechanisms in future.
Xiaohong Zhuang
Chinese University of Hong Kong
Read the Original
This page is a summary of: Plant-specific mitochondrial fission machinery connects mitochondrial dynamics and mitophagosome formation for piecemeal mitophagy, Proceedings of the National Academy of Sciences, August 2025, Proceedings of the National Academy of Sciences,
DOI: 10.1073/pnas.2504921122.
You can read the full text:
Contributors
The following have contributed to this page
