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Lefèvre,Agnès; Consoli,Luciano; Gaziola,Salete A.; Pellegrino,Ana Paula; Azevedo,Ricardo A.; Damerval,Catherine. |
The Opaque-2 (O2) gene encodes a transcriptional activator specifically expressed for grain development of maize. o2 mutants have an opaque and chalky kernel, with a decrease in zein storage protein content, and an increase in the proportions of lysine and tryptophan. In this review, we present recent results investigating genetic properties of the O2 network, using transcriptome and proteome approaches, associated with measurements of activities of enzymes of the aspartate pathway and lysine degradation. The structural polymorphism at the O2 locus was investigated by RFLP in a collection of 51 maize inbred lines. Most polymorphic sites were found outside the coding regions. We then searched for relationships between RFLP polymorphism and (i) mRNA... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Zein; Aspartate kinase; Lysine oxoglutarate reductase/saccharopine dehydrogenase; Polymorphism. |
Ano: 2002 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162002000200031 |
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Kato,Fabiana Hibary; Carvalho,Marcia Eugenia Amaral; Gaziola,Salete Aparecida; Piotto,Fernando Angelo; Azevedo,Ricardo Antunes. |
ABSTRACT: In general, the effects of Cadmium (Cd) on crop quality are evaluated solely by Cd accumulation in the edible plant parts; thus, the potential effects on several nutritional features are not often taken into account. This study evaluated Cd effects on the enzymatic activities of lysine (Lys) metabolism, storage protein and amino acid profile in maize. Stress parameters were also assessed. In vegetative organs, Cd was accumulated in the following decreasing order: roots > stems > leaves. Cadmium accumulation in grains decreased at grain maturity (from 0.25 to 0.07 µg g−1 DW). In leaves, neither hydrogen peroxide content nor superoxide dismutase, catalase, ascorbate peroxide and guaiacol peroxidase activities did not change in Cd-treated... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Zea mays L.; Aspartate kinase; Corn; Dihydrodipicolinate synthase; Heavy metal. |
Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162020000101300 |
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Ferreira,Renato Rodrigues; Vendemiatti,Ariane; Meinhardt,Lyndel Wayne; Lea,Peter John; Azevedo,Ricardo Antunes. |
Cereal seeds are poor in essential amino acids, particularly lysine, tryptophan and threonine. The amino acids lysine and threonine are synthesized in the aspartate pathway. Although most of the enzymes of the aspartate pathway have been isolated and characterized in higher plant species, the metabolism of lysine and threonine is totally unknown in sorghum. We have isolated two enzymes, aspartate kinase (AK) and homoserine dehydrogenase (HSDH) from sorghum. Optimum assay conditions were established for the determination of AK and HSDH activities. The highest level of activity was observed in immature seeds. AK was shown to be inhibited by threonine and lysine indicating the existence of at least two isoenzymes, one sensitive to threonine inhibition and the... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Amino acids; Aspartate kinase; Homoserine dehydrogenase; Lysine; Threonine. |
Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202004000200005 |
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