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Barley Viridis-k links an evolutionarily conserved C-type ferredoxin to chlorophyll biosynthesis

Stuart, David LU ; Sandström, Malin ; Youssef, Helmy M. LU ; Zakhrabekova, Shakhira LU ; Jensen, Poul Erik ; Bollivar, David LU and Hansson, Mats LU (2021) In Plant Cell 33(8). p.2834-2849
Abstract

Ferredoxins are single-electron carrier proteins involved in various cellular reactions. In chloroplasts, the most abundant ferredoxin accepts electrons from photosystem I and shuttles electrons via ferredoxin NADPþ oxidoreductase to generate NADPH or directly to ferredoxin dependent enzymes. In addition, plants contain other isoforms of ferredoxins. Two of these, named FdC1 and FdC2 in Arabidopsis thaliana, have C-terminal extensions and functions that are poorly understood. Here we identified disruption of the orthologous FdC2 gene in barley (Hordeum vulgare L.) mutants at the Viridis-k locus; these mutants are deficient in the aerobic cyclase reaction of chlorophyll biosynthesis. The magnesium-protoporphyrin IX monomethyl... (More)

Ferredoxins are single-electron carrier proteins involved in various cellular reactions. In chloroplasts, the most abundant ferredoxin accepts electrons from photosystem I and shuttles electrons via ferredoxin NADPþ oxidoreductase to generate NADPH or directly to ferredoxin dependent enzymes. In addition, plants contain other isoforms of ferredoxins. Two of these, named FdC1 and FdC2 in Arabidopsis thaliana, have C-terminal extensions and functions that are poorly understood. Here we identified disruption of the orthologous FdC2 gene in barley (Hordeum vulgare L.) mutants at the Viridis-k locus; these mutants are deficient in the aerobic cyclase reaction of chlorophyll biosynthesis. The magnesium-protoporphyrin IX monomethyl ester cyclase is one of the least characterized enzymes of the chlorophyll biosynthetic pathway and its electron donor has long been sought. Agroinfiltrations showed that the viridis-k phenotype could be complemented in vivo by Viridis-k but not by canonical ferredoxin. VirK could drive the cyclase reaction in vitro and analysis of cyclase mutants showed that in vivo accumulation of VirK is dependent on cyclase enzyme levels. The chlorophyll deficient phenotype of viridis-k mutants suggests that VirK plays an essential role in chlorophyll biosynthesis that cannot be replaced by other ferredoxins, thus assigning a specific function to this isoform of C-type ferredoxins.

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organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Plant Cell
volume
33
issue
8
pages
16 pages
publisher
American Society of Plant Biologists
external identifiers
  • scopus:85114236644
  • pmid:34051099
ISSN
1040-4651
DOI
10.1093/plcell/koab150
language
English
LU publication?
yes
id
934819f0-a5b1-4613-b2c7-b28dd5711f35
date added to LUP
2021-10-08 13:03:53
date last changed
2024-06-15 17:35:15
@article{934819f0-a5b1-4613-b2c7-b28dd5711f35,
  abstract     = {{<p>Ferredoxins are single-electron carrier proteins involved in various cellular reactions. In chloroplasts, the most abundant ferredoxin accepts electrons from photosystem I and shuttles electrons via ferredoxin NADP<sup>þ</sup> oxidoreductase to generate NADPH or directly to ferredoxin dependent enzymes. In addition, plants contain other isoforms of ferredoxins. Two of these, named FdC1 and FdC2 in Arabidopsis thaliana, have C-terminal extensions and functions that are poorly understood. Here we identified disruption of the orthologous FdC2 gene in barley (Hordeum vulgare L.) mutants at the Viridis-k locus; these mutants are deficient in the aerobic cyclase reaction of chlorophyll biosynthesis. The magnesium-protoporphyrin IX monomethyl ester cyclase is one of the least characterized enzymes of the chlorophyll biosynthetic pathway and its electron donor has long been sought. Agroinfiltrations showed that the viridis-k phenotype could be complemented in vivo by Viridis-k but not by canonical ferredoxin. VirK could drive the cyclase reaction in vitro and analysis of cyclase mutants showed that in vivo accumulation of VirK is dependent on cyclase enzyme levels. The chlorophyll deficient phenotype of viridis-k mutants suggests that VirK plays an essential role in chlorophyll biosynthesis that cannot be replaced by other ferredoxins, thus assigning a specific function to this isoform of C-type ferredoxins.</p>}},
  author       = {{Stuart, David and Sandström, Malin and Youssef, Helmy M. and Zakhrabekova, Shakhira and Jensen, Poul Erik and Bollivar, David and Hansson, Mats}},
  issn         = {{1040-4651}},
  language     = {{eng}},
  number       = {{8}},
  pages        = {{2834--2849}},
  publisher    = {{American Society of Plant Biologists}},
  series       = {{Plant Cell}},
  title        = {{Barley Viridis-k links an evolutionarily conserved C-type ferredoxin to chlorophyll biosynthesis}},
  url          = {{http://dx.doi.org/10.1093/plcell/koab150}},
  doi          = {{10.1093/plcell/koab150}},
  volume       = {{33}},
  year         = {{2021}},
}