A single recessive mutation in the proteolytic machinery of Arabidopsis chloroplasts impairs photoprotection and photosynthesis upon cold stress

Maggie Levy*, Andreas Bachmair, Zach Adam

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

2 Scopus citations


Intracellular proteases, together with molecular chaperones, are components of the cellular protein quality control system. Although the identity of chloroplast proteases has been revealed in recent years, little is known about their regulation. As a first step towards identifying unknown functional or regulatory components of the chloroplast proteolytic machinery, a genetic screen was devised with the aim of generating Arabidopsis thaliana (L.) Heynh. mutants impaired in chloroplast protein degradation. A streptomycin-resistance gene was fused to a cDNA construct that encodes an unstable mutant of the OE33 protein. This chimeric gene was used for transforming Arabidopsis plants. Analysis of transgenic plants revealed a correlation between streptomycin resistance and accumulation of the recombinant fusion protein. Seeds from transgenic plants that were sensitive to streptomycin were chemically mutagenized and screened for resistance to streptomycin. Such resistance could be due to stabilization of the protein caused by a mutation in the chloroplast proteolytic machinery. Genetic analysis of one of the mutants showed the mutation to be recessive, in a single nuclear gene. Further characterization of the mutant revealed that it was not a result of increased transcription of the transgene. Moreover, chloroplast lysates from the mutant plant showed decreased ATP-dependent degradation of a chloroplast protein substrate, consistent with the conclusion that the mutation impaired the proteolytic machinery. Physiological analysis revealed that upon cold stress, photoprotection and photosynthesis in the mutant was inhibited, suggesting that the chloroplast proteolytic machinery is involved in repairing damage incurred to the photosynthetic machinery upon exposure to cold temperatures.

Original languageAmerican English
Pages (from-to)396-405
Number of pages10
Issue number3
StatePublished - Jan 2004

Bibliographical note

Funding Information:
Acknowledgements We thank Dr. Klaudia Brix for skillful help with confocal microscopy, Dr. Victor Raskin for excellent help and advice on chlorophyll fluorescence measurements, and Dr. Nir Ohad and Profs. Avi Levy and Itzhak Ohad for insightful discussions. This work was supported by grants from The Austrian Friends of The Hebrew University (to A.B. and Z.A.), the Israel Ministry of Science (to Z.A.), and the US–Israel Binational Agricultural Research and Development Fund—BARD (to Z.A.).


  • Arabidopsis
  • Chloroplast
  • Photoprotection
  • Photosynthesis
  • Proteolysis


Dive into the research topics of 'A single recessive mutation in the proteolytic machinery of Arabidopsis chloroplasts impairs photoprotection and photosynthesis upon cold stress'. Together they form a unique fingerprint.

Cite this