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Registro Completo |
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Biblioteca(s): |
Embrapa Soja. |
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Data corrente: |
18/11/1992 |
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Data da última atualização: |
27/10/2004 |
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Autoria: |
HARPER, J. E. |
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Afiliação: |
USDA/ARS and Department of Agronomy, University of Illinois, Urbana, Illinois 61801, USA. |
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Título: |
Nitrogen metabolism mutants of soybean. |
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Ano de publicação: |
1989 |
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Fonte/Imprenta: |
In: CONFERENCIA MUNDIAL DE INVESTIGACION EN SOJA, 4., 1989, Buenos Aires. Actas... Buenos Aires: AASOJA, 1989. |
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Volume: |
t.1 |
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Páginas: |
p.212-216. |
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Idioma: |
Inglês |
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Conteúdo: |
The inhibitory effect of NO3- on nodulation of soybean, Glycine max (L.) Merr., has been well established. A mutation approach to alter nodulation response to NO3- has been under-taken. Mutagenized seed were screened in the M2 generation for altered nitrate reductase (NR) activity (chlorate toxicity and in vivo NR assay), for increased nodulation when cultured on NO3- (visual selection), and for nonnodulating mutants. Three NR mutants were isolated and biochemically characterized. One mutant, designated nr1, lacks both the NADH and the NADPH constitutive NR activities. Two additional mutants kack only the NADPH constitutive NR activity. All three mutants retain the substrate-inducible NR enzyme and exhibit normal NO3- uptake and metabolism profiles. This indi-cates that the substrate-inducible NR enzyme is sufficiently active to metabolize all incoming NO3-. The NADPH-dependent constitutive NR enzyme was shown to be capable of further reducing nitrite to nitric oxide under experimental conditions (NO2- accumulation in the tissue). Since NO2- does not accumulate under normal growth conditions, this pathway appears unimportant to intact plants. The function of the constitutive NR isoforms remains unknown. Nodulation was normal in all three NR mutants indicating that presence of constitutive NR isoforms is not related to nodulation control. Three mutants have also been selected which exhibit increased nodulation capability in either the absence or presence of NO3-. These mutants appear to be altered in the autoregula- MenosThe inhibitory effect of NO3- on nodulation of soybean, Glycine max (L.) Merr., has been well established. A mutation approach to alter nodulation response to NO3- has been under-taken. Mutagenized seed were screened in the M2 generation for altered nitrate reductase (NR) activity (chlorate toxicity and in vivo NR assay), for increased nodulation when cultured on NO3- (visual selection), and for nonnodulating mutants. Three NR mutants were isolated and biochemically characterized. One mutant, designated nr1, lacks both the NADH and the NADPH constitutive NR activities. Two additional mutants kack only the NADPH constitutive NR activity. All three mutants retain the substrate-inducible NR enzyme and exhibit normal NO3- uptake and metabolism profiles. This indi-cates that the substrate-inducible NR enzyme is sufficiently active to metabolize all incoming NO3-. The NADPH-dependent constitutive NR enzyme was shown to be capable of further reducing nitrite to nitric oxide under experimental conditions (NO2- accumulation in the tissue). Since NO2- does not accumulate under normal growth conditions, this pathway appears unimportant to intact plants. The function of the constitutive NR isoforms remains unknown. Nodulation was normal in all three NR mutants indicating that presence of constitutive NR isoforms is not related to nodulation control. Three mutants have also been selected which exhibit increased nodulation capability in either the absence or presence of NO3-. These mutant... Mostrar Tudo |
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Palavras-Chave: |
EUA; Soybean; USA. |
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Thesagro: |
Fixação de Nitrogênio; Metabolismo; Nodulação; Soja. |
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Thesaurus Nal: |
metabolism; nitrogen fixation; nodulation. |
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Categoria do assunto: |
-- |
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Marc: |
LEADER 02234naa a2200265 a 4500
001 1452979
005 2004-10-27
008 1989 bl uuuu u00u1 u #d
100 1 $aHARPER, J. E.
245 $aNitrogen metabolism mutants of soybean.
260 $c1989
300 $ap.212-216. t.1
490 $vt.1
520 $aThe inhibitory effect of NO3- on nodulation of soybean, Glycine max (L.) Merr., has been well established. A mutation approach to alter nodulation response to NO3- has been under-taken. Mutagenized seed were screened in the M2 generation for altered nitrate reductase (NR) activity (chlorate toxicity and in vivo NR assay), for increased nodulation when cultured on NO3- (visual selection), and for nonnodulating mutants. Three NR mutants were isolated and biochemically characterized. One mutant, designated nr1, lacks both the NADH and the NADPH constitutive NR activities. Two additional mutants kack only the NADPH constitutive NR activity. All three mutants retain the substrate-inducible NR enzyme and exhibit normal NO3- uptake and metabolism profiles. This indi-cates that the substrate-inducible NR enzyme is sufficiently active to metabolize all incoming NO3-. The NADPH-dependent constitutive NR enzyme was shown to be capable of further reducing nitrite to nitric oxide under experimental conditions (NO2- accumulation in the tissue). Since NO2- does not accumulate under normal growth conditions, this pathway appears unimportant to intact plants. The function of the constitutive NR isoforms remains unknown. Nodulation was normal in all three NR mutants indicating that presence of constitutive NR isoforms is not related to nodulation control. Three mutants have also been selected which exhibit increased nodulation capability in either the absence or presence of NO3-. These mutants appear to be altered in the autoregula-
650 $ametabolism
650 $anitrogen fixation
650 $anodulation
650 $aFixação de Nitrogênio
650 $aMetabolismo
650 $aNodulação
650 $aSoja
653 $aEUA
653 $aSoybean
653 $aUSA
773 $tIn: CONFERENCIA MUNDIAL DE INVESTIGACION EN SOJA, 4., 1989, Buenos Aires. Actas... Buenos Aires: AASOJA, 1989.
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Registro original: |
Embrapa Soja (CNPSO) |
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