A chloroplast light-regulated oxidative sensor for moderate light intensity in Arabidopsis

Inbal Dangoor, Hadas Peled-Zehavi, Gal Wittenberg, Avihai Danon*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

71 Citations (Scopus)

Abstract

The transition from dark to light involves marked changes in the redox reactions of photosynthetic electron transport and in chloroplast stromal enzyme activity even under mild light and growth conditions. Thus, it is not surprising that redox regulation is used to dynamically adjust and coordinate the stromal and thylakoid compartments. While oxidation of regulatory proteins is necessary for the regulation, the identity and the mechanism of action of the oxidizing pathway are still unresolved. Here, we studied the oxidation of a thylakoid-associated atypical thioredoxin-type protein, ACHT1, in the Arabidopsis thaliana chloroplast. We found that after a brief period of net reduction in plants illuminated with moderate light intensity, a significant oxidation reaction of ACHT1 arises and counterbalances its reduction. Interestingly, ACHT1 oxidation is driven by 2-Cys peroxiredoxin (Prx), which in turn eliminates peroxides. The ACHT1 and 2-Cys Prx reaction characteristics in plants further indicated that ACHT1 oxidation is linked with changes in the photosynthetic production of peroxides. Our findings that plants with altered redox poise of the ACHT1 and 2-Cys Prx pathway show higher nonphotochemical quenching and lower photosynthetic electron transport infer a feedback regulatory role for this pathway.

Original languageEnglish
Pages (from-to)1894-1906
Number of pages13
JournalPlant Cell
Volume24
Issue number5
DOIs
Publication statusPublished - May 2012

Funding

Israeli Science Foundation; Minerva FoundationWe thank Nir Keren and Itzhak Ohad for their guiding advice concerning the chlorophyll fluorescence measurements. We thank Meir Edelman and Ami Navon for their valuable suggestions and Ami Navon for his generous gift of HA-conjugated beads. This study was supported by grants from the Israeli Science Foundation and the Minerva Foundation. A.D. is the incumbent of The Henry and Bertha Benson Chair, Weizmann Institute of Science.

All Science Journal Classification (ASJC) codes

  • Plant Science
  • Cell Biology

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