Data/hora: 22/06/2024 02:46:38

Biblioteca(s): 	Embrapa Milho e Sorgo.	
Data corrente: 	08/01/1998	
Data da última atualização: 	13/07/2018	
Autoria: 	GEETHA, K. B.; LENDING, C. R.; LOPES, M. A.; WALLACE, J. C.; LARKINS, B. A.	
Título: 	Opaque-2 modifiers increase y-zein synthesis and alter its spatial distribution in maize endosperm.	
Ano de publicação: 	1991	
Fonte/Imprenta: 	Plant Cell, Rockville, v. 3, n. 11, p. 1207-1219, Nov. 1991.	
Idioma: 	Inglês	
Conteúdo: 	Through the action of opaque-2 modifier genes, the soft, floury of opaque-2 mutants is converted to a vitreous phenotype. This change in endosperm texture is associated with a twofold to threefold increase in y-zein content. To investigate the effect of opaque-2 modifiers on the expression of y-zein genes, we analyzed the synthesis and distribution of y-zein protein and the level of y-zein mRNAs in developing endosperms of the inbreds W644 and W644o2, a modified opaque-2 mutant Poll 34 QP,, and their reciprocal F1 hybrids. We also characterized the number and organization of y-zein genes in these and related maize genotypes. Our studies show that opaque-2 modifiers are semidominant genes, resulting in a twofold to threefold increase in y-zein gene expression in both opaque-2 and normal genetic backgrounds. The increase in gene expression appears to e a conseguence of copies in modified as well as nonmodified genetic backgrounds. Ultrastructural studies showed that y-zein occurs in high concentration in the first few subaleurone cells of nonmodified endosperm, but high concentrations of y-zein occur in the subaleurone and central endosperm cells of modified opaque-2 mutants. The increased concentration and distribution of y-zein in modified endosperm are highly correlated with the activity of opaque-2 modifier genes.	
Palavras-Chave: 	Maize; Molecular; Opaco-2; Opaque 2; Protein; QPM.	
Thesagro: 	Milho; Qualidade; Zea Mays.	
Thesaurus Nal: 	molecular biology.	
Categoria do assunto: 	S Ciências Biológicas	
Registro original: 	Embrapa Milho e Sorgo (CNPMS)	
Exemplares: 	CNPMS - (6927-1) - ADD - AP - DD -  -  -  - DIS