Xyloglucan mobilisation in cotyledons of developing plantlets of Hymenaea courbaril L. (Leguminosae-Caesalpinoideae)

Tiné, Marco Aurélio Silva; Cortelazzo, Ângelo Luiz; Buckeridge, Marcos Silveira

doi:10.1016/s0168-9452(99)00245-9

Cited by 58 publications

(78 citation statements)

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“…To our knowledge, this study is the first evidence of a relationship between endogenous levels of IAA and storage xyloglucan mobilization in the cotyledons of H. courbaril, a shade-tolerant tree from the neotropical rain forests. Among the possibilities for further studies are the influences of IAA on vein establishment in the cotyledons, the expression of cell wall-related genes, and on apoplastic pH, since acid pH optima (3.2-4.5) for the activities of xyloglucan hydrolases have been demonstrated in cotyledons of H. courbaril (Alcântara, 2000;Tiné et al, 2000) and in C. langsdorffii (Alcântara et al, 1999).…”

Section: Auxin and Xyloglucan Mobilizationmentioning

confidence: 99%

“…The detachment dates were chosen on the basis of the results obtained by Tiné et al (2000). These time points were chosen to isolate the cotyledons before, during, and after the start of xyloglucan mobilization.…”

Section: Experiments and Treatment Descriptionsmentioning

confidence: 99%

“…Protein concentration was estimated according to Bradford (1976), and the activities of b-galactosidase, b-glucosidase, a-xylosidase (only in the second experiment), and XEH were performed. All enzyme activity measurements were adapted from Tiné et al (2000).…”

Section: Determination Of Enzyme Activitiesmentioning

confidence: 99%

“…In cotyledons of H. courbaril, Tiné et al (2000) showed that xyloglucan is mobilized after germination and that Glc and Suc are produced concomitant with xyloglucan disassembly. Furthermore, these authors detected the same four xyloglucan-degrading enzyme activities that have been found in nasturtium.…”

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The Control of Storage Xyloglucan Mobilization in Cotyledons of Hymenaea courbaril

et al. 2004

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Hymenaea courbaril is a leguminous tree species from the neotropical rain forests. Its cotyledons are largely enriched with a storage cell wall polysaccharide (xyloglucan). Studies of cell wall storage polymers have been focused mostly on the mechanisms of their disassembly, whereas the control of their mobilization and the relationship between their metabolism and seedling development is not well understood. Here, we show that xyloglucan mobilization is strictly controlled by the development of first leaves of the seedling, with the start of its degradation occurring after the beginning of eophyll (first leaves) expansion. During the period of storage mobilization, an increase in the levels of xyloglucan hydrolases, starch, and free sugars were observed in the cotyledons. Xyloglucan mobilization was inhibited by shoot excision, darkness, and by treatment with the auxin-transport inhibitor N-1-naphthylphthalamic acid. Analyses of endogenous indole-3-acetic acid in the cotyledons revealed that its increase in concentration is followed by the rise in xyloglucan hydrolase activities, indicating that auxin is directly related to xyloglucan mobilization. Cotyledons detached during xyloglucan mobilization and treated with 2,4-dichlorophenoxyacetic acid showed a similar mobilization rate as in attached cotyledons. This hormonal control is probably essential for the ecophysiological performance of this species in their natural environment since it is the main factor responsible for promoting synchronism between shoot growth and reserve degradation. This is likely to increase the efficiency of carbon reserves utilization by the growing seedling in the understorey light conditions of the rain forest.

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Section: Auxin and Xyloglucan Mobilizationmentioning

confidence: 99%

Section: Experiments and Treatment Descriptionsmentioning

confidence: 99%

Section: Determination Of Enzyme Activitiesmentioning

confidence: 99%

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The Control of Storage Xyloglucan Mobilization in Cotyledons of Hymenaea courbaril

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“…Análise dos oligossacarídeos de xiloglucano por cromatografia aniônica de alta resolução com detecção por pulso amperométrico (HPAEC/PAD) -Os oligossacarídeos de xiloglucano foram analisados em cromatografia líquida de alta resolução em sistema Dionex DX-500, utilizando coluna Carbo Pak PA100, eluída com um gradiente de acetato de sódio (35-70 mM em 50 minutos) e hidróxido de sódio 88 mM constante, com fluxo de 0,9 mL min -1 . A identificação dos picos foi realizada conforme Tiné et al (2000). Cromatografia em gel de exclusão molecular -Os Figura 1.…”

Section: Methodsunclassified

Isolamento de oligossacarídeos de xiloglucano de dicotiledôneas através de hidrólise enzimática e cromatografia de exclusão molecular

Júnior¹,

Braga²,

Buckeridge³

2006

Rev. bras. Bot.

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-(Isolation of xyloglucan oligossacharides from dicots using enzymatic hydrolyses and gel permeation chromatography). Oligosaccharides from xyloglucan, a plant cell wall polysaccharide, have been considered as signaling molecules capable of regulating cell growth and expansion. The purification of such oligosaccharides is an essential requirement to evaluate their biological activity. In the present work, xyloglucans extracted from seeds of copaiba (Copaifera langsdorffii Desf.) and bean cell suspension cultures (Phaseolus vulgaris L.) were hydrolyzed with cellulase (endo-glucanase) to obtain xyloglucan oligosaccharides (OXGs). The OXGs were separated by gel permeation chromatography and analysed by high performance anion exchange chromatography with pulse amperometric detector (HPAEC/PAD). The results indicate that these procedures were suitable for purification of OXGs since XLLG and XXXG were 90% and XXFG 80% pure, showing the expected biological activity.Key words -cell wall, oligosaccharides, purification, xyloglucan RESUMO -(Isolamento de oligossacarídeos de xiloglucano de dicotiledôneas através de hidrólise enzimática e cromatografia de exclusão molecular). Oligossacarídeos derivados do xiloglucano, um polissacarídeo constituinte da parede celular vegetal, vêm sendo considerados como moléculas capazes de sinalizar e/ou regular eventos relacionados ao crescimento e à expansão celular. A purificação desses oligossacarídeos é imprescindível para a realização de ensaios relativos à sua atividade biológica. Neste trabalho, xiloglucanos foram extraídos a partir de sementes de copaíba (Copaifera langsdorffii Desf.) e suspensões celulares de feijão (Phaseolus vulgaris L.) e hidrolisados com celulase (endo-glucanase) para obtenção dos oligossacarídeos de xiloglucano, os OXGs. Os resultados obtidos mostram que a técnica de cromatografia dupla em gel de exclusão molecular foi eficiente para purificação dos oligossacarídeos, apresentando OXGs dos tipos XLLG e XXXG com grau de pureza próximo a 90%, e do tipo XXFG próximo de 80%.

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Mechanisms and Genes Involved in GerminationSensu Stricto

Nonogaki

Chen

Bradford

Seed Development, Dormancy and Germination

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Xyloglucan mobilisation in cotyledons of developing plantlets of Hymenaea courbaril L. (Leguminosae-Caesalpinoideae)

Cited by 58 publications

References 20 publications

The Control of Storage Xyloglucan Mobilization in Cotyledons of Hymenaea courbaril

The Control of Storage Xyloglucan Mobilization in Cotyledons of Hymenaea courbaril

Isolamento de oligossacarídeos de xiloglucano de dicotiledôneas através de hidrólise enzimática e cromatografia de exclusão molecular

Mechanisms and Genes Involved in GerminationSensu Stricto

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