Consulta: subjectFacets:"Xyloglucan"
Registros recuperados: 4
Data/hora: 01/06/2024 02:32:01

Diurnal changes in storage carbohydrate metabolism in cotyledons of the tropical tree Hymenaea courbaril L. (Leguminosae)
Provedor de dados: 88
Autores: Amaral,Lourdes Isabel Velho do; Santos,Henrique P.; Rossatto,Davi Rodrigo; Buckeridge,Marcos Silveira.
The cotyledons of Hymenaea courbaril store large amounts of xyloglucan, a cell wall polysaccharide that is believed to serve as storage for the period of seedling establishment. During storage mobilisation, xyloglucan seems to be degraded by a continuous process that starts right after radicle protrusion and follows up to the establishment of photosynthesis. Here we show evidence that events related to the hydrolases activities and production (α-xylosidase, β-galactosidase, β-glucosidase and xyloglucan endo-β-transglucosilase) as well as auxin, showed changes that follow the diurnal cycle. The period of higher hydrolases activities was between 6pm and 6am, which is out of phase with photosynthesis. Among the enzymes, α-xilosidase seems to be more important...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Enzyme activity; IAA; Α-xylosidase; XTH; Xyloglucan.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-84042012000400008

Occurrence of xyloglucan containing protuberances in the storage cell walls of cotyledons of Hymenaea courbaril L.
Provedor de dados: 88
Autores: TINÉ,MARCO AURÉLIO SILVA; CORTELAZZO,ANGELO; BUCKERIDGE,MARCOS S.
Despite the suggestions of its pectic composition, no clear evidence for this has been presented. Here we show the occurrence of such a structure in walls of cells from cotyledons of Hymenaea courbariI L. These cells are known to accumulate large amounts of storage xyloglucan in the wall and, in this case, the protuberances seem to contain this storage polysaccharide rather than pectin. A hypothetical sequence of events leading from wall strands to protuberances was assembled based on scanning electron microscopy observations. On this basis, a tentative model for how polysaccharides are distributed into the wall, near the regions where protuberances are found, is proposed to explain the presence of storage xyloglucan in their composition.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Xyloglucan; Pectin; Cell wall; Protuberances; Hymenaea courbaril.
Ano: 2000
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-84042000000400007

Effect of atmospheric CO2 enrichment on the establishment of seedlings of Jatobá, Hymenaea Courbaril L. (Leguminosae, Caesalpinioideae)
Provedor de dados: 49
Autores: Aidar,M.P.M.; Martinez,C.A.; Costa,A.C.; Costa,P.M.F.; Dietrich,S.M.C.; Buckeridge,M.S.
Plants grown in elevated CO2 environments may exhibit photosynthetic acclimation or down regulation, which is characterised by reduced rates of photosynthesis. In most cases of CO2-induced photosynthetic acclimation, the reduced rates of photosynthesis were still higher than those detected in plants growing at ambient CO2 concentrations. In this work we present a study on the behaviour of seedlings of Hymenaea courbaril, a late secondary/climax species that is one of the most important trees in mature tropical forests of the Americas. After germination, the seedling of H. courbaril increases its rate of growth due to the mobilisation of massive amounts of a storage cell wall polysaccharide (xyloglucan) from its cotyledons. In our experiments, germinated...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Photosynthesis; CO2 enrichment; Hymenaea courbaril; Storage mobilisation; Root:shoot ratio; Seedling growth; Cotyledons; Open top chamber; Xyloglucan; Biodiversity.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1676-06032002000100008

Synthesis and characterization of a cysteine xyloglucan conjugate as mucoadhesive polymer
Provedor de dados: 60
Autores: Bhalekar,Mangesh; Sonawane,Savita; Shimpi,Shamkant.
The aim of this study was to improve the mucoadhesive potential of xyloglucan polymer by the covalent attachment of cysteine as thiol moiety. The parent polymer xyloglucan was chemically modified by introducing sulphydryl bearing compound L-cysteine HCl. Different batches of xyloglucan-cysteine conjugates were prepared at varying reaction pH (2-6) and evaluated for optimum thiol incorporation, disulphide group content, swelling behavior, rheological properties and mucoadhesive properties. The obtained conjugates characterized in vitro by quantification of immobilized thiol groups; showed maximum thiol incorporation on xyloglucan (7.67 ± 0.14 %) at pH 5. The disulphide group content was found maximum (2.83 ± 0.12) at pH 6. The water uptake at end of 4 h was...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Mucoadhesion; Thiomer; Xyloglucan; L-cysteine HCl.
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-82502013000200010