| |
|
|
|
Registro Completo |
|
Biblioteca(s): |
Embrapa Cerrados; Embrapa Soja. |
|
Data corrente: |
23/02/2000 |
|
Data da última atualização: |
23/02/2000 |
|
Autoria: |
NEPOMUCENO, A. L. |
|
Título: |
Physiological and molecular responses of plants to water deficit. |
|
Ano de publicação: |
1998 |
|
Fonte/Imprenta: |
[S.l.]: University of Arkansas, 1998. |
|
Páginas: |
269p. |
|
Idioma: |
Inglês |
|
Notas: |
PhD. Thesis. |
|
Conteúdo: |
Tolerance to drought in plants results from networks of mechanisms working isolated or in combination. Genotypes that differ in tolerance to water-deficit stress should have qualitative and/or quantitative differences in gene expression. Therefore, to identify and isolate genes, which may differ among four cotton genotypes with diverse responses to water deprivaton, Differential Display (DDRT-PCR) was used. These genotypes were first physiologically characterized in growth chamber and greenhouse experiments. Water and osmotic potential of roots and leaves, photosynthetic rate and relative water content were some of the physiological parameters used to measure plant responses during and after the water defficit applied. Cultivar Siokra L-23 and the wild type T-1521, two drought tolerant genotypes, showed a significant ability of osmotic adjust during water deficit. Photosynthetic rate and relative water content were maintained near control values in the two tolerant genotypes. However, cultivar CS 50 and Stoneville 506, showed significant sensitivity to the water deficit applied, confirming previous observations. These results guided subsequent work with DDRT-PCR using mRNA samples colected during these experiments. Fifty-two cDNA fragments differentially expressed during water deficit were identified using DD. The differentially displayed fragments were isolated from the polyacrylamide gels and cloned in pGEM-T vectors. After cloning they were sequenced using thermocycling dideoxynucleotide chain termination protocols. Search of gene banks revealed 17 clones with high homology to known genes, and 20 clones with low homology, while 15 clones had no homologous entries. Among the sequences that showed high homology was a heat shock protein that binds to calmodulin. This gene was expressed only in the water-deficit tolerant genotypes (Siokra L-23 and T-1521) during the stress. Another gene identified by homology was trehalose-6-phosphate synthase. This enzyme is part of the metabolic pathway for production of trehalose, a sugar known to osmoprotect cell membranes during desiccation. The differentially expressed gene sequences could have use in screening germplasm banks for similar genotypes, in plant physiology studies, and in molecular mapping of plant responses to water deficit. MenosTolerance to drought in plants results from networks of mechanisms working isolated or in combination. Genotypes that differ in tolerance to water-deficit stress should have qualitative and/or quantitative differences in gene expression. Therefore, to identify and isolate genes, which may differ among four cotton genotypes with diverse responses to water deprivaton, Differential Display (DDRT-PCR) was used. These genotypes were first physiologically characterized in growth chamber and greenhouse experiments. Water and osmotic potential of roots and leaves, photosynthetic rate and relative water content were some of the physiological parameters used to measure plant responses during and after the water defficit applied. Cultivar Siokra L-23 and the wild type T-1521, two drought tolerant genotypes, showed a significant ability of osmotic adjust during water deficit. Photosynthetic rate and relative water content were maintained near control values in the two tolerant genotypes. However, cultivar CS 50 and Stoneville 506, showed significant sensitivity to the water deficit applied, confirming previous observations. These results guided subsequent work with DDRT-PCR using mRNA samples colected during these experiments. Fifty-two cDNA fragments differentially expressed during water deficit were identified using DD. The differentially displayed fragments were isolated from the polyacrylamide gels and cloned in pGEM-T vectors. After cloning they were sequenced using thermocycling d... Mostrar Tudo |
|
Palavras-Chave: |
Drought resistance; Genotypes; Plant pohysiology; Plant water relation; Plante response. |
|
Thesagro: |
Água; Algodão; Deficiência Hídrica; Fisiologia; Genética Molecular; Genótipo; Gossypium Hirsutum; Planta; Relação Água-Planta; Resistência a Seca; Stress. |
|
Thesaurus Nal: |
cotton; molecular genetics; water deprivation. |
|
Categoria do assunto: |
-- |
|
Marc: |
LEADER 03263nam a2200361 a 4500
001 1559664
005 2000-02-23
008 1998 bl uuuu m 00u1 u #d
100 1 $aNEPOMUCENO, A. L.
245 $aPhysiological and molecular responses of plants to water deficit.
260 $a[S.l.]: University of Arkansas$c1998
300 $a269p.
500 $aPhD. Thesis.
520 $aTolerance to drought in plants results from networks of mechanisms working isolated or in combination. Genotypes that differ in tolerance to water-deficit stress should have qualitative and/or quantitative differences in gene expression. Therefore, to identify and isolate genes, which may differ among four cotton genotypes with diverse responses to water deprivaton, Differential Display (DDRT-PCR) was used. These genotypes were first physiologically characterized in growth chamber and greenhouse experiments. Water and osmotic potential of roots and leaves, photosynthetic rate and relative water content were some of the physiological parameters used to measure plant responses during and after the water defficit applied. Cultivar Siokra L-23 and the wild type T-1521, two drought tolerant genotypes, showed a significant ability of osmotic adjust during water deficit. Photosynthetic rate and relative water content were maintained near control values in the two tolerant genotypes. However, cultivar CS 50 and Stoneville 506, showed significant sensitivity to the water deficit applied, confirming previous observations. These results guided subsequent work with DDRT-PCR using mRNA samples colected during these experiments. Fifty-two cDNA fragments differentially expressed during water deficit were identified using DD. The differentially displayed fragments were isolated from the polyacrylamide gels and cloned in pGEM-T vectors. After cloning they were sequenced using thermocycling dideoxynucleotide chain termination protocols. Search of gene banks revealed 17 clones with high homology to known genes, and 20 clones with low homology, while 15 clones had no homologous entries. Among the sequences that showed high homology was a heat shock protein that binds to calmodulin. This gene was expressed only in the water-deficit tolerant genotypes (Siokra L-23 and T-1521) during the stress. Another gene identified by homology was trehalose-6-phosphate synthase. This enzyme is part of the metabolic pathway for production of trehalose, a sugar known to osmoprotect cell membranes during desiccation. The differentially expressed gene sequences could have use in screening germplasm banks for similar genotypes, in plant physiology studies, and in molecular mapping of plant responses to water deficit.
650 $acotton
650 $amolecular genetics
650 $awater deprivation
650 $aÁgua
650 $aAlgodão
650 $aDeficiência Hídrica
650 $aFisiologia
650 $aGenética Molecular
650 $aGenótipo
650 $aGossypium Hirsutum
650 $aPlanta
650 $aRelação Água-Planta
650 $aResistência a Seca
650 $aStress
653 $aDrought resistance
653 $aGenotypes
653 $aPlant pohysiology
653 $aPlant water relation
653 $aPlante response
Download
Esconder MarcMostrar Marc Completo |
|
Registro original: |
Embrapa Cerrados (CPAC) |
|
|
Biblioteca |
ID |
Origem |
Tipo/Formato |
Classificação |
Cutter |
Registro |
Volume |
Status |
URL |
Voltar
|
|
|
 | Acesso ao texto completo restrito à biblioteca da Embrapa Agrobiologia. Para informações adicionais entre em contato com cnpab.biblioteca@embrapa.br. |
Registro Completo
|
Biblioteca(s): |
Embrapa Agrobiologia. |
|
Data corrente: |
25/11/2005 |
|
Data da última atualização: |
25/11/2005 |
|
Autoria: |
JOURAND, P.; RENIER, A.; RAPIOR, S.; FARIA, S. M. de; PRIN, Y.; GALIANA, A.; GIRAUD, E.; DREYFUS, B. |
|
Título: |
Role of methylotrophy during symbiosis between methylobacterium nodulans and Crotalaria podocarpa. |
|
Ano de publicação: |
2005 |
|
Fonte/Imprenta: |
Molecular Plant-Microbe Interactions, St. Paul, v. 18, n. 10, p. 1061-1068, 2005. |
|
Idioma: |
Inglês |
|
Conteúdo: |
Some rare leguminous plants of the genus Crotalaria are specifically nodulated by the methylotrophic bacterium Methylabocterium nodulans. In this study, the expression and role of bacterial methylotrophy were investigated during symbiosis between M. nodulans, strain ORS 2060t, and its host legume, Crotalaria podocarpa. Using lacZ fusion to the mxaF gene,we showed that the methylotroph genes are expressed in the root nodules, suggesting methylotrophic activity during symbiosis. In addition, loos of the bacterial methylotrophic function significantly affected plant development. Indeed, inoculation of M. nodulans nonmethylotroph mutants in C. podocarpa decreased the total root nodule number per plant up to 60%, decreased the whole-plant nitrogen fixation capacity up to 42%, and reduced the total dry plant biomass up to 46% compared with the wild-type strain. In contrast, inoculation of the legume C. podocarpa with nonmethylotyrophic mutants complemented with functional mxa genes restored the symbiotic wild phenotype. These results demonstrate the key role of methylotrophic during symbiosis between M. nodulans and C. podocarpa. |
|
Palavras-Chave: |
Crotalaria podocarpa. |
|
Thesagro: |
Álcool; Metanol; Simbiose. |
|
Thesaurus NAL: |
alcohols; methanol; symbiosis. |
|
Categoria do assunto: |
-- |
|
Marc: |
LEADER 01922naa a2200289 a 4500
001 1628551
005 2005-11-25
008 2005 bl --- 0-- u #d
100 1 $aJOURAND, P.
245 $aRole of methylotrophy during symbiosis between methylobacterium nodulans and Crotalaria podocarpa.
260 $c2005
520 $aSome rare leguminous plants of the genus Crotalaria are specifically nodulated by the methylotrophic bacterium Methylabocterium nodulans. In this study, the expression and role of bacterial methylotrophy were investigated during symbiosis between M. nodulans, strain ORS 2060t, and its host legume, Crotalaria podocarpa. Using lacZ fusion to the mxaF gene,we showed that the methylotroph genes are expressed in the root nodules, suggesting methylotrophic activity during symbiosis. In addition, loos of the bacterial methylotrophic function significantly affected plant development. Indeed, inoculation of M. nodulans nonmethylotroph mutants in C. podocarpa decreased the total root nodule number per plant up to 60%, decreased the whole-plant nitrogen fixation capacity up to 42%, and reduced the total dry plant biomass up to 46% compared with the wild-type strain. In contrast, inoculation of the legume C. podocarpa with nonmethylotyrophic mutants complemented with functional mxa genes restored the symbiotic wild phenotype. These results demonstrate the key role of methylotrophic during symbiosis between M. nodulans and C. podocarpa.
650 $aalcohols
650 $amethanol
650 $asymbiosis
650 $aÁlcool
650 $aMetanol
650 $aSimbiose
653 $aCrotalaria podocarpa
700 1 $aRENIER, A.
700 1 $aRAPIOR, S.
700 1 $aFARIA, S. M. de
700 1 $aPRIN, Y.
700 1 $aGALIANA, A.
700 1 $aGIRAUD, E.
700 1 $aDREYFUS, B.
773 $tMolecular Plant-Microbe Interactions, St. Paul$gv. 18, n. 10, p. 1061-1068, 2005.
Download
Esconder MarcMostrar Marc Completo |
|
Registro original: |
Embrapa Agrobiologia (CNPAB) |
|
|
Biblioteca |
ID |
Origem |
Tipo/Formato |
Classificação |
Cutter |
Registro |
Volume |
Status |
Fechar
|
| Expressão de busca inválida. Verifique!!! |
|
|
