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Registro Completo |
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Biblioteca(s): |
Embrapa Milho e Sorgo. |
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Data corrente: |
06/10/2003 |
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Data da última atualização: |
05/06/2018 |
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Tipo da produção científica: |
Artigo em Periódico Indexado |
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Autoria: |
PINEROS, M. A.; MAGALHAES, J. V.; ALVES, V. M. C.; KOCHIAN, L. V. |
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Afiliação: |
JURANDIR VIEIRA DE MAGALHAES, CNPMS; VERA MARIA CARVALHO ALVES, CNPMS. |
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Título: |
The physiology and biophysics of an aluminum tolerance mechanism based on root citrate exudation in maize. |
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Ano de publicação: |
2002 |
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Fonte/Imprenta: |
Plant Physiology, Bethesda, v. 129, p. 1194-1206, 2002. |
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Idioma: |
Inglês |
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Conteúdo: |
Al-induced release of Al-chelating ligands (primarily organic acids) into the rhizosphere from the root apex has been identified as a major Al tolerance mechanism in a number of plants species. In the present study, we conducted physiological investigations to study the spatial and temporal characteristcs of Al-activated root organic acid exudation, as well as changes in root organic acid content and Al accumulation, in an AL-tolerant maize (Zea mays) single cross (SLP 181/71 x Cateto Colombia 96/71). These investigations were integrated with biophysical studies using the patch-clamp technique to examine Al-activated anion channel activity in protoplasts isolated from different regions of the mazie root. Exposure to Al nearly instantaneously activated a concentration-dependent citrate release, which saturated at rates close to 0,5 nmol citrate h1 root -1. with the half-maximal rates of citrate release occurring at about 20 um Al3+ activity. Comparison of citrate exudation rates between decapped and capped roots indicated the root cap does not play a major role in perceiving the Al signal or in the exudation process. Spatial analysis indicated that the predominant citrate exudation is not confined to the root apex, but could be found as far as 5 cm beyond the root cap, involving cortex and stelar cells. Patch clamp recordings obtained in whole-cell and outside-out patches confirmed the presence of an Al-inducible plasma membrane anion channel in protoplasts isolated from stelar or cortical tissues. The unitary conductance of this channel was 23 to 55 pS. Our results suggest that this transporter mediates the Al-induced citrate release observed in the intact tissue. In addition to the rapid Al activation of citrate release , a slower, Al-inducible increase in root citrate content was also observed. These findings led us to speculate that in addition to the Al exclusion mechanism based on root citrate exudation, a second internal Al tolerance mechanism may be operating based on Al-inducible changes in organic acid synthesis and compartmentation. We discuss our findings in terms of recent genetic studies of Al tolerance in maize, which suggest that Al tolerance in maize is a complex trait. MenosAl-induced release of Al-chelating ligands (primarily organic acids) into the rhizosphere from the root apex has been identified as a major Al tolerance mechanism in a number of plants species. In the present study, we conducted physiological investigations to study the spatial and temporal characteristcs of Al-activated root organic acid exudation, as well as changes in root organic acid content and Al accumulation, in an AL-tolerant maize (Zea mays) single cross (SLP 181/71 x Cateto Colombia 96/71). These investigations were integrated with biophysical studies using the patch-clamp technique to examine Al-activated anion channel activity in protoplasts isolated from different regions of the mazie root. Exposure to Al nearly instantaneously activated a concentration-dependent citrate release, which saturated at rates close to 0,5 nmol citrate h1 root -1. with the half-maximal rates of citrate release occurring at about 20 um Al3+ activity. Comparison of citrate exudation rates between decapped and capped roots indicated the root cap does not play a major role in perceiving the Al signal or in the exudation process. Spatial analysis indicated that the predominant citrate exudation is not confined to the root apex, but could be found as far as 5 cm beyond the root cap, involving cortex and stelar cells. Patch clamp recordings obtained in whole-cell and outside-out patches confirmed the presence of an Al-inducible plasma membrane anion channel in protoplasts isolated from stel... Mostrar Tudo |
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Thesagro: |
Alumínio; Milho. |
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Categoria do assunto: |
-- |
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Marc: |
LEADER 02777naa a2200181 a 4500
001 1487223
005 2018-06-05
008 2002 bl uuuu u00u1 u #d
100 1 $aPINEROS, M. A.
245 $aThe physiology and biophysics of an aluminum tolerance mechanism based on root citrate exudation in maize.$h[electronic resource]
260 $c2002
520 $aAl-induced release of Al-chelating ligands (primarily organic acids) into the rhizosphere from the root apex has been identified as a major Al tolerance mechanism in a number of plants species. In the present study, we conducted physiological investigations to study the spatial and temporal characteristcs of Al-activated root organic acid exudation, as well as changes in root organic acid content and Al accumulation, in an AL-tolerant maize (Zea mays) single cross (SLP 181/71 x Cateto Colombia 96/71). These investigations were integrated with biophysical studies using the patch-clamp technique to examine Al-activated anion channel activity in protoplasts isolated from different regions of the mazie root. Exposure to Al nearly instantaneously activated a concentration-dependent citrate release, which saturated at rates close to 0,5 nmol citrate h1 root -1. with the half-maximal rates of citrate release occurring at about 20 um Al3+ activity. Comparison of citrate exudation rates between decapped and capped roots indicated the root cap does not play a major role in perceiving the Al signal or in the exudation process. Spatial analysis indicated that the predominant citrate exudation is not confined to the root apex, but could be found as far as 5 cm beyond the root cap, involving cortex and stelar cells. Patch clamp recordings obtained in whole-cell and outside-out patches confirmed the presence of an Al-inducible plasma membrane anion channel in protoplasts isolated from stelar or cortical tissues. The unitary conductance of this channel was 23 to 55 pS. Our results suggest that this transporter mediates the Al-induced citrate release observed in the intact tissue. In addition to the rapid Al activation of citrate release , a slower, Al-inducible increase in root citrate content was also observed. These findings led us to speculate that in addition to the Al exclusion mechanism based on root citrate exudation, a second internal Al tolerance mechanism may be operating based on Al-inducible changes in organic acid synthesis and compartmentation. We discuss our findings in terms of recent genetic studies of Al tolerance in maize, which suggest that Al tolerance in maize is a complex trait.
650 $aAlumínio
650 $aMilho
700 1 $aMAGALHAES, J. V.
700 1 $aALVES, V. M. C.
700 1 $aKOCHIAN, L. V.
773 $tPlant Physiology, Bethesda$gv. 129, p. 1194-1206, 2002.
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Registro original: |
Embrapa Milho e Sorgo (CNPMS) |
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Registro Completo
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Biblioteca(s): |
Embrapa Instrumentação. |
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Data corrente: |
14/09/2012 |
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Data da última atualização: |
16/10/2018 |
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Tipo da produção científica: |
Artigo em Anais de Congresso |
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Autoria: |
CORRÊA, T. R. A.; FERNANDES, C. P.; OLIVEIRA, F. B. de; FORATO, L. A.; BERNARDES FILHO, R. |
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Afiliação: |
LUCIMARA APARECIDA FORATO, CNPDIA; RUBENS BERNARDES FILHO, CNPDIA. |
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Título: |
Análise por ângulo de contato e microscopia de força atômica de filmes comestíveis à base de zeína com adição de nanofibras de celulose. |
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Ano de publicação: |
2012 |
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Fonte/Imprenta: |
In: WORKSHOP DA REDE DE NANOTECNOLOGIA APLICADA AO AGRONEGÓCIO, 6., 2012, Fortaleza. Anais... São Carlos: Embrapa Instrumentação: Embrapa Agroindústria Tropical, 2012. p. 96-98. Editores: Maria Alice Martins, MOrsyleide de Freitas Rosa, Men de Sá Moreira de Souza Filho, Nicodemos Moreira dos Santos Junior, Odílio Benedito Garrido de Assis, Caue Ribeiro, Luiz Henrique Capparelli Mattoso. |
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ISSN: |
2175-8395 |
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Idioma: |
Português |
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Palavras-Chave: |
Filmes e revestimentos comestíveis; Nanofibras de celulose; Preservação de alimentos. |
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Thesagro: |
Zeína. |
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Categoria do assunto: |
-- |
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URL: |
https://ainfo.cnptia.embrapa.br/digital/bitstream/item/184414/1/Analise-por-angulo-de-contato-e-microscopia-de-forca-atomica-de-filmes-comestiveis-a-base-de-zeina-com-adicao-de-nanofibras-de-celulose.pdf
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Marc: |
LEADER 01077nam a2200205 a 4500
001 1933788
005 2018-10-16
008 2012 bl uuuu u00u1 u #d
022 $a2175-8395
100 1 $aCORRÊA, T. R. A.
245 $aAnálise por ângulo de contato e microscopia de força atômica de filmes comestíveis à base de zeína com adição de nanofibras de celulose.$h[electronic resource]
260 $aIn: WORKSHOP DA REDE DE NANOTECNOLOGIA APLICADA AO AGRONEGÓCIO, 6., 2012, Fortaleza. Anais... São Carlos: Embrapa Instrumentação: Embrapa Agroindústria Tropical, 2012. p. 96-98. Editores: Maria Alice Martins, MOrsyleide de Freitas Rosa, Men de Sá Moreira de Souza Filho, Nicodemos Moreira dos Santos Junior, Odílio Benedito Garrido de Assis, Caue Ribeiro, Luiz Henrique Capparelli Mattoso.$c2012
650 $aZeína
653 $aFilmes e revestimentos comestíveis
653 $aNanofibras de celulose
653 $aPreservação de alimentos
700 1 $aFERNANDES, C. P.
700 1 $aOLIVEIRA, F. B. de
700 1 $aFORATO, L. A.
700 1 $aBERNARDES FILHO, R.
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