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Registro Completo
Biblioteca(s): |
Embrapa Milho e Sorgo. |
Data corrente: |
02/01/2001 |
Data da última atualização: |
07/06/2018 |
Tipo da produção científica: |
Artigo em Periódico Indexado |
Autoria: |
GAZIOLA, S. A.; ALESSI, E. S.; GUIMARAES, P. E. O.; DAMERVAL, C.; AZEVEDO, R. A. |
Afiliação: |
PAULO EVARISTO DE O GUIMARAES, CNPMS. |
Título: |
Quality protein maize: a biochemical study of enzymes involved in lysine metabolism. |
Ano de publicação: |
1999 |
Fonte/Imprenta: |
Journal of Agricultural and Food Chemistry, Washington, v. 47, n. 3, p. 1268-1275, 1999. |
Idioma: |
Inglês |
Conteúdo: |
Quality protein maize (QPM) varieties have been produced by the introduction of opaque-2 modifier genes. Two QPM varieties, BR451, and BR473, a wild type and an opaque-2 variety, have beeen used to study key enzymes controlling lysine metabolism in the endosperm during development. Aspartate kinase and homoserine dehydrogenase enzymes. which are involved in lysine and threonine biosynthesis, respectively, exhibited identical activity patterns during endosperm development, with a maximum specific activity at 16 days after pollination. The QPM varieties exhibited higher levels of aspartate kinase activity in the endosperm, suggesting an increased rate of lysine biosynthesis when compared to the opaque-2 and wild-type genotypes. Similar results were observed for the lysine ketoglutarate reductase and saccharopine dehydrogenase enzymes, which form a single bifunctional polypetide involved in endosperm lysine degradation. Both enzyme activity were strongly reduced in the opaque-2 maize variety when compared to the wild-type maize, whereas the QPM varieties exhibited even lower levels of lysine ketoglutarate reductase-saccharopine dehydrogenase activities when compared to the opaque-2 variety. The developmental pattern of ensyme activity showed a different profile when compared to the enzymes involved in lysine biosynthesis, with activity being detected only 12-16 days after pollination (DAP) and maximum activities ~24 DAP. These results also suggest that the modifier genes have intensified the effect of the opaque-2 mutation on lysine ketoglutarate reductase-saccharopine dehydrogenase. These alterations lead to an increase in soluble lysine in the endosperm of the QPM varieties when compared to the opaque-2 and wild type. MenosQuality protein maize (QPM) varieties have been produced by the introduction of opaque-2 modifier genes. Two QPM varieties, BR451, and BR473, a wild type and an opaque-2 variety, have beeen used to study key enzymes controlling lysine metabolism in the endosperm during development. Aspartate kinase and homoserine dehydrogenase enzymes. which are involved in lysine and threonine biosynthesis, respectively, exhibited identical activity patterns during endosperm development, with a maximum specific activity at 16 days after pollination. The QPM varieties exhibited higher levels of aspartate kinase activity in the endosperm, suggesting an increased rate of lysine biosynthesis when compared to the opaque-2 and wild-type genotypes. Similar results were observed for the lysine ketoglutarate reductase and saccharopine dehydrogenase enzymes, which form a single bifunctional polypetide involved in endosperm lysine degradation. Both enzyme activity were strongly reduced in the opaque-2 maize variety when compared to the wild-type maize, whereas the QPM varieties exhibited even lower levels of lysine ketoglutarate reductase-saccharopine dehydrogenase activities when compared to the opaque-2 variety. The developmental pattern of ensyme activity showed a different profile when compared to the enzymes involved in lysine biosynthesis, with activity being detected only 12-16 days after pollination (DAP) and maximum activities ~24 DAP. These results also suggest that the modifier genes have i... Mostrar Tudo |
Palavras-Chave: |
Opaco-2; Opaque-2; Protein; QPM; Quality. |
Thesagro: |
Enzima; Lisina; Milho; Proteína; Qualidade; Zea Mays. |
Thesaurus NAL: |
enzymes; lysine. |
Categoria do assunto: |
S Ciências Biológicas |
Marc: |
LEADER 02601naa a2200325 a 4500 001 1485183 005 2018-06-07 008 1999 bl uuuu u00u1 u #d 100 1 $aGAZIOLA, S. A. 245 $aQuality protein maize$ba biochemical study of enzymes involved in lysine metabolism.$h[electronic resource] 260 $c1999 520 $aQuality protein maize (QPM) varieties have been produced by the introduction of opaque-2 modifier genes. Two QPM varieties, BR451, and BR473, a wild type and an opaque-2 variety, have beeen used to study key enzymes controlling lysine metabolism in the endosperm during development. Aspartate kinase and homoserine dehydrogenase enzymes. which are involved in lysine and threonine biosynthesis, respectively, exhibited identical activity patterns during endosperm development, with a maximum specific activity at 16 days after pollination. The QPM varieties exhibited higher levels of aspartate kinase activity in the endosperm, suggesting an increased rate of lysine biosynthesis when compared to the opaque-2 and wild-type genotypes. Similar results were observed for the lysine ketoglutarate reductase and saccharopine dehydrogenase enzymes, which form a single bifunctional polypetide involved in endosperm lysine degradation. Both enzyme activity were strongly reduced in the opaque-2 maize variety when compared to the wild-type maize, whereas the QPM varieties exhibited even lower levels of lysine ketoglutarate reductase-saccharopine dehydrogenase activities when compared to the opaque-2 variety. The developmental pattern of ensyme activity showed a different profile when compared to the enzymes involved in lysine biosynthesis, with activity being detected only 12-16 days after pollination (DAP) and maximum activities ~24 DAP. These results also suggest that the modifier genes have intensified the effect of the opaque-2 mutation on lysine ketoglutarate reductase-saccharopine dehydrogenase. These alterations lead to an increase in soluble lysine in the endosperm of the QPM varieties when compared to the opaque-2 and wild type. 650 $aenzymes 650 $alysine 650 $aEnzima 650 $aLisina 650 $aMilho 650 $aProteína 650 $aQualidade 650 $aZea Mays 653 $aOpaco-2 653 $aOpaque-2 653 $aProtein 653 $aQPM 653 $aQuality 700 1 $aALESSI, E. S. 700 1 $aGUIMARAES, P. E. O. 700 1 $aDAMERVAL, C. 700 1 $aAZEVEDO, R. A. 773 $tJournal of Agricultural and Food Chemistry, Washington$gv. 47, n. 3, p. 1268-1275, 1999.
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