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Analysis of gun phenotype in barley magnesium chelatase and Mg-protoporphyrin IX monomethyl ester cyclase mutants

Gadjieva, Rena LU ; Axelsson, Eva LU ; Olsson, Ulf LU and Hansson, Mats LU (2005) In Plant Physiology and Biochemistry 43(10-11). p.901-908
Abstract
The ability of barley (Hordeum vulgare L.) chlorophyll biosynthetic mutants to regulate the expression of Lhc genes was analyzed by a microarray approach. The Lhc genes are located in the nucleus and encode chlorophyll a/b binding proteins of the light-harvesting complex. The chlorophyll a/b binding proteins are some of the many proteins, which are imported to the chloroplast. It has been suggested that the chloroplast can regulate expression of nuclear genes encoding chloroplast proteins, using a chlorophyll biosynthetic intermediate such as Mg-protoporphyrin IX (MP) or Mg-protoporphyrin IX monomethyl ester (MPE) as a signal molecule. These compounds are intermediates between the two enzymes magnesium-chelatase (EC 6.6.1.1) and... (More)
The ability of barley (Hordeum vulgare L.) chlorophyll biosynthetic mutants to regulate the expression of Lhc genes was analyzed by a microarray approach. The Lhc genes are located in the nucleus and encode chlorophyll a/b binding proteins of the light-harvesting complex. The chlorophyll a/b binding proteins are some of the many proteins, which are imported to the chloroplast. It has been suggested that the chloroplast can regulate expression of nuclear genes encoding chloroplast proteins, using a chlorophyll biosynthetic intermediate such as Mg-protoporphyrin IX (MP) or Mg-protoporphyrin IX monomethyl ester (MPE) as a signal molecule. These compounds are intermediates between the two enzymes magnesium-chelatase (EC 6.6.1.1) and Mg-protoporphyrin IX monomethyl ester cyclase (EC 1.14.13.81) in the chlorophyll biosynthetic pathway. Genomes uncoupled (gun) mutants are defective in the chloroplast-to-nucleus signal transduction and express Lhc even when chloroplast development is inhibited by the herbicide norflurazon. We show that barley xantha-f, -g and -h mutants, defective in the three Mg-chelatase genes, have a gun phenotype. In contrast, a xantha-l mutant, defective in a gene of Mg-protoporphyrin monomethyl ester cyclase did not. Genome uncoupling in the xantha-f, -g, -h and -l mutants was also analyzed in absence of norflurazon. All mutants showed transcription of Lhc. This was unexpected in the case of xantha-l as this mutant showed accumulation of MPE, which has been suggested to be one of the two negative regulators of Lhc transcription. We suggest that chlorophyll intermediates may only function as signal molecules at an early developmental stage of chloroplast development. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Plant Physiology and Biochemistry
volume
43
issue
10-11
pages
901 - 908
publisher
Elsevier
external identifiers
  • wos:000234435300001
  • scopus:28944443048
ISSN
1873-2690
DOI
10.1016/j.plaphy.2005.08.003
language
English
LU publication?
yes
id
bf0225c0-4326-4538-bb99-6e0c2813bd61 (old id 158603)
date added to LUP
2007-07-05 09:44:56
date last changed
2017-05-14 04:12:15
@article{bf0225c0-4326-4538-bb99-6e0c2813bd61,
  abstract     = {The ability of barley (Hordeum vulgare L.) chlorophyll biosynthetic mutants to regulate the expression of Lhc genes was analyzed by a microarray approach. The Lhc genes are located in the nucleus and encode chlorophyll a/b binding proteins of the light-harvesting complex. The chlorophyll a/b binding proteins are some of the many proteins, which are imported to the chloroplast. It has been suggested that the chloroplast can regulate expression of nuclear genes encoding chloroplast proteins, using a chlorophyll biosynthetic intermediate such as Mg-protoporphyrin IX (MP) or Mg-protoporphyrin IX monomethyl ester (MPE) as a signal molecule. These compounds are intermediates between the two enzymes magnesium-chelatase (EC 6.6.1.1) and Mg-protoporphyrin IX monomethyl ester cyclase (EC 1.14.13.81) in the chlorophyll biosynthetic pathway. Genomes uncoupled (gun) mutants are defective in the chloroplast-to-nucleus signal transduction and express Lhc even when chloroplast development is inhibited by the herbicide norflurazon. We show that barley xantha-f, -g and -h mutants, defective in the three Mg-chelatase genes, have a gun phenotype. In contrast, a xantha-l mutant, defective in a gene of Mg-protoporphyrin monomethyl ester cyclase did not. Genome uncoupling in the xantha-f, -g, -h and -l mutants was also analyzed in absence of norflurazon. All mutants showed transcription of Lhc. This was unexpected in the case of xantha-l as this mutant showed accumulation of MPE, which has been suggested to be one of the two negative regulators of Lhc transcription. We suggest that chlorophyll intermediates may only function as signal molecules at an early developmental stage of chloroplast development.},
  author       = {Gadjieva, Rena and Axelsson, Eva and Olsson, Ulf and Hansson, Mats},
  issn         = {1873-2690},
  language     = {eng},
  number       = {10-11},
  pages        = {901--908},
  publisher    = {Elsevier},
  series       = {Plant Physiology and Biochemistry},
  title        = {Analysis of gun phenotype in barley magnesium chelatase and Mg-protoporphyrin IX monomethyl ester cyclase mutants},
  url          = {http://dx.doi.org/10.1016/j.plaphy.2005.08.003},
  volume       = {43},
  year         = {2005},
}