Reduced chlorophyll biosynthesis in heterozygous barley magnesium chelatase mutants.
Plant Physiol Biochem
; 78: 10-4, 2014 May.
Article
en En
| MEDLINE
| ID: mdl-24607574
ABSTRACT
Chlorophyll biosynthesis is initiated by magnesium chelatase, an enzyme composed of three proteins, which catalyzes the insertion of Mg2+ into protoporphyrin IX to produce Mg-protoporphyrin IX. In barley (Hordeum vulgare L.) the three proteins are encoded by Xantha-f, Xantha-g and Xantha-h. Two of the gene products, XanH and XanG, belong to the structurally conserved family of AAA+ proteins (ATPases associated with various cellular activities) and form a complex involving six subunits of each protein. The complex functions as an ATP-fueled motor of the magnesium chelatase that uses XanF as substrate, which is the catalytic subunit responsible for the insertion of Mg2+ into protoporphyrin IX. Previous studies have shown that semi-dominant Xantha-h mutations result in non-functional XanH subunits that participate in the formation of inactive AAA complexes. In the present study, we identify severe mutations in the barley mutants xantha-h.38, -h.56 and -h.57. A truncated form of the protein is seen in xantha-h.38, whereas no XanH is detected in xantha-h.56 and -h.57. Heterozygous mutants show a reduction in chlorophyll content by 14-18% suggesting a slight semi-dominance of xantha-h.38, -h.56 and -h.57, which otherwise have been regarded as recessive mutations.
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Base de datos:
MEDLINE
Asunto principal:
Proteínas de Plantas
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Hordeum
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Clorofila
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Liasas
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Mutación
Idioma:
En
Revista:
Plant Physiol Biochem
Asunto de la revista:
BIOQUIMICA
/
BOTANICA
Año:
2014
Tipo del documento:
Article