Gene duplication confers enhanced expression of 27-kDa γ-zein for endosperm modification in quality protein maize.
Proc Natl Acad Sci U S A
; 113(18): 4964-9, 2016 May 03.
Article
em En
| MEDLINE
| ID: mdl-27092004
ABSTRACT
The maize opaque2 (o2) mutant has a high nutritional value but it develops a chalky endosperm that limits its practical use. Genetic selection for o2 modifiers can convert the normally chalky endosperm of the mutant into a hard, vitreous phenotype, yielding what is known as quality protein maize (QPM). Previous studies have shown that enhanced expression of 27-kDa γ-zein in QPM is essential for endosperm modification. Taking advantage of genome-wide association study analysis of a natural population, linkage mapping analysis of a recombinant inbred line population, and map-based cloning, we identified a quantitative trait locus (qγ27) affecting expression of 27-kDa γ-zein. qγ27 was mapped to the same region as the major o2 modifier (o2 modifier1) on chromosome 7 near the 27-kDa γ-zein locus. qγ27 resulted from a 15.26-kb duplication at the 27-kDa γ-zein locus, which increases the level of gene expression. This duplication occurred before maize domestication; however, the gene structure of qγ27 appears to be unstable and the DNA rearrangement frequently occurs at this locus. Because enhanced expression of 27-kDa γ-zein is critical for endosperm modification in QPM, qγ27 is expected to be under artificial selection. This discovery provides a useful molecular marker that can be used to accelerate QPM breeding.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Zeína
/
Genes de Plantas
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Zea mays
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Duplicação Gênica
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Endosperma
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
Proc Natl Acad Sci U S A
Ano de publicação:
2016
Tipo de documento:
Article