Details
| Original language | English |
|---|---|
| Pages (from-to) | 1064-1078 |
| Number of pages | 15 |
| Journal | Plant Journal |
| Volume | 120 |
| Issue number | 30 |
| Publication status | Published - 30 Oct 2024 |
Abstract
Arabidopsis uracil phosphoribosyltransferase (UPP) is an essential enzyme and plants lacking this enzyme are strongly compromised in chloroplast function. Our analysis of UPP amiRNA mutants has confirmed that this vital function is crucial to establish a fully functional photosynthesis as the RIESKE iron sulfur protein (PetC) is almost absent, leading to a block in photosynthetic electron transport. Interestingly, this function appears to be unrelated to nucleotide homeostasis since nucleotide levels were not altered in the studied mutants. Transcriptomics and proteomic analysis showed that protein homeostasis but not gene expression is most likely responsible for this observation and high light provoked an upregulation of protease levels, including thylakoid filamentation temperature-sensitive 1, 5 (FtsH), caseinolytic protease proteolytic subunit 1 (ClpP1), and processing peptidases, as well as components of the chloroplast protein import machinery in UPP amiRNA lines. Strongly reduced PetC amounts were not only detected by immunoblot from mature plants but in addition in a de-etiolation experiment with young seedlings and are causing reduced high light-induced non-photochemical quenching Φ(NPQ) but increased unregulated energy dissipation Φ(NO). This impaired photosynthesis results in an inability to induce flavonoid biosynthesis. In addition, the levels of the osmoprotectants raffinose, proline, and fumarate were found to be reduced. In sum, our work suggests that UPP assists in stabilization PetC during import, processing or targeting to the thylakoid membrane, or protects it against proteolytic degradation.
Keywords
- chloroplast, cytochrome bf, nucleotides, photosynthesis, protease
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)
- Genetics
- Agricultural and Biological Sciences(all)
- Plant Science
- Biochemistry, Genetics and Molecular Biology(all)
- Cell Biology
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In: Plant Journal, Vol. 120, No. 30, 30.10.2024, p. 1064-1078.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Uracil phosphoribosyltransferase is required to establish a functional cytochrome b6f complex
AU - Scherer, Vanessa
AU - Bellin, Leo
AU - Schwenkert, Serena
AU - Lehmann, Martin
AU - Rinne, Jannis
AU - Witte, Claus Peter
AU - Jahnke, Kathrin
AU - Richter, Andreas
AU - Pruss, Tobias
AU - Lau, Anne
AU - Waller, Lisa
AU - Stein, Sebastian
AU - Leister, Dario
AU - Möhlmann, Torsten
N1 - Publisher Copyright: © 2024 The Author(s). The Plant Journal published by Society for Experimental Biology and John Wiley & Sons Ltd.
PY - 2024/10/30
Y1 - 2024/10/30
N2 - Arabidopsis uracil phosphoribosyltransferase (UPP) is an essential enzyme and plants lacking this enzyme are strongly compromised in chloroplast function. Our analysis of UPP amiRNA mutants has confirmed that this vital function is crucial to establish a fully functional photosynthesis as the RIESKE iron sulfur protein (PetC) is almost absent, leading to a block in photosynthetic electron transport. Interestingly, this function appears to be unrelated to nucleotide homeostasis since nucleotide levels were not altered in the studied mutants. Transcriptomics and proteomic analysis showed that protein homeostasis but not gene expression is most likely responsible for this observation and high light provoked an upregulation of protease levels, including thylakoid filamentation temperature-sensitive 1, 5 (FtsH), caseinolytic protease proteolytic subunit 1 (ClpP1), and processing peptidases, as well as components of the chloroplast protein import machinery in UPP amiRNA lines. Strongly reduced PetC amounts were not only detected by immunoblot from mature plants but in addition in a de-etiolation experiment with young seedlings and are causing reduced high light-induced non-photochemical quenching Φ(NPQ) but increased unregulated energy dissipation Φ(NO). This impaired photosynthesis results in an inability to induce flavonoid biosynthesis. In addition, the levels of the osmoprotectants raffinose, proline, and fumarate were found to be reduced. In sum, our work suggests that UPP assists in stabilization PetC during import, processing or targeting to the thylakoid membrane, or protects it against proteolytic degradation.
AB - Arabidopsis uracil phosphoribosyltransferase (UPP) is an essential enzyme and plants lacking this enzyme are strongly compromised in chloroplast function. Our analysis of UPP amiRNA mutants has confirmed that this vital function is crucial to establish a fully functional photosynthesis as the RIESKE iron sulfur protein (PetC) is almost absent, leading to a block in photosynthetic electron transport. Interestingly, this function appears to be unrelated to nucleotide homeostasis since nucleotide levels were not altered in the studied mutants. Transcriptomics and proteomic analysis showed that protein homeostasis but not gene expression is most likely responsible for this observation and high light provoked an upregulation of protease levels, including thylakoid filamentation temperature-sensitive 1, 5 (FtsH), caseinolytic protease proteolytic subunit 1 (ClpP1), and processing peptidases, as well as components of the chloroplast protein import machinery in UPP amiRNA lines. Strongly reduced PetC amounts were not only detected by immunoblot from mature plants but in addition in a de-etiolation experiment with young seedlings and are causing reduced high light-induced non-photochemical quenching Φ(NPQ) but increased unregulated energy dissipation Φ(NO). This impaired photosynthesis results in an inability to induce flavonoid biosynthesis. In addition, the levels of the osmoprotectants raffinose, proline, and fumarate were found to be reduced. In sum, our work suggests that UPP assists in stabilization PetC during import, processing or targeting to the thylakoid membrane, or protects it against proteolytic degradation.
KW - chloroplast
KW - cytochrome bf
KW - nucleotides
KW - photosynthesis
KW - protease
UR - http://www.scopus.com/inward/record.url?scp=85205251760&partnerID=8YFLogxK
U2 - 10.1111/tpj.17036
DO - 10.1111/tpj.17036
M3 - Article
AN - SCOPUS:85205251760
VL - 120
SP - 1064
EP - 1078
JO - Plant Journal
JF - Plant Journal
SN - 0960-7412
IS - 30
ER -