Dialypetalanthus Fuscescens Kuhlm. (Dialypetalanthaceae): The Problematic Taxonomic Position of an Amazonian Endemic

Piesschaert, Frederic; Robbrecht, Elmar; Smets, Erik

doi:10.2307/2400002

Cited by 18 publications

(24 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, they were shown to predominate in leaf cell walls of three woody Rubiaceae species from tropical environment, and also in the monospecific Dialypetalanthaceae (Braga et al 1998;Moraes et al 2001), which is suggested to be closely related to Rubiaceae (Piesschaert et al 1997). Therefore, the analysis of primary cell walls from suspension culture of R. jasminoides confirmed the previous suggestion that arabinoxylan occurs in a proportion that is higher than what has been usually reported for primary cell walls of most eudicots (Carpita and Gibeaut 1993).…”

Section: The Cell Suspension Wallssupporting

confidence: 82%

Cell wall polysaccharides from cell suspension cultures of the Atlantic Forest tree Rudgea jasminoides (Rubiaceae)

Júnior

Cavalari

Carpita

et al. 2010

Trees

View full text Add to dashboard Cite

Rudgea jasminoides (Rubiaceae) is a tropical tree species native of the Atlantic Forest in the south of Brazil. Previous studies with leaf cell walls of R. jasminoides showed a different proportion of cross-linked glycans compared to what is usually reported for eudicots. However, due to the difficulties of working with whole plant organs, cell suspensions of R. jasminoides, consisting of predominantly undifferentiated cells with mainly primary cell walls, were used to examine cell walls and extracellular soluble polysaccharides (EP) released into the culture medium. Sugar composition and linkage analysis showed homogalacturonans, xylogalacturonans and arabinogalactans to be the predominant EP. In the cell wall, homogalacturonans and arabinogalactans are the major pectins, and xyloglucans and xylans are the major crosslinking glycans. The presence of xylogalacturonans in the R. jasminoides cell cultures seems to be related to the occurrence of a homogeneous cell suspension with loosely attached cells. Although all alkali extractions from the cell walls yielded amounts of xyloglucan that exceed those of the xylans, the latter was found in a proportion that is higher than what has been usually reported for primary cell walls of most eudicots. The xyloglucan from cell walls of cell suspension cultures of R. jasminoides has low fucosylation levels and high proportion of galactosyl residues, a branching pattern commonly found in storage cellwall xyloglucans.

show abstract

Section: The Cell Suspension Wallssupporting

confidence: 82%

Cell wall polysaccharides from cell suspension cultures of the Atlantic Forest tree Rudgea jasminoides (Rubiaceae)

Júnior

Cavalari

Carpita

et al. 2010

Trees

View full text Add to dashboard Cite

show abstract

“…is an endemic Amazonian tree, being the only species of the Dialypetalanthaceae. Its taxonomic position is problematic since this species combines characters such as buds protected by stipules, paracytic stomata, numerous unitegmic ovules, and a well-developed endosperm that suggest a close relationship with the Rubiaceae, with primitive features such as free petals and dimerous floral whorls that are enough to set it apart from the Gentianales (Piesschaert et al 1997). When in vegetative stage, D. fuscescens is hardly distinguishable from certain RubiaceaeCinchonoideae (Piesschaert et al 1995).…”

Section: Introductionmentioning

confidence: 99%

“…More recently the affinity of this species with Rubiales or Gentianales has been proposed (Dahlgren & Thorne 1984) and accepted instead. However, the lack of ontogenetic and micro-and macromolecular data on D. fuscescens has limited a proper judgement about the possible relationships of this species with other plants (Piesschaert et al 1997).…”

Section: Introductionmentioning

confidence: 99%

Comparative analysis of leaf cell-wall polysaccharides of Dialypetalanthus fuscescens and Bathysa meridionalis: evidence of biochemical similarities between Dialypetalanthaceae and Rubiaceae-Cinchonoideae

2001

View full text Add to dashboard Cite

-(Comparative analysis of leaf cell-wall polysaccharides of Dialypetalanthus fuscescens and Bathysa meridionalis: evidence of biochemical similarities between Dialypetalanthaceae and Rubiaceae-Cinchonoideae). Dialypetalanthus fuscescens is an Amazonian endemic species with problematic taxonomic position. This neotropical rainforest tree belongs to the monospecific Dialypetalanthaceae. In the present work, we analysed the leaf cell-wall polysaccharide composition of Dialypetalanthus fuscescens and compared it to that of Bathysa meridionalis (Rubiaceae-Cinchonoideae). Glycosyl composition and glycosyl-linkage analysis indicated that both species have similar cell wall composition. Arabinogalactans were the major component of the pectic polysaccharides and xylans, although being reported in minor amounts in dicots, were found to be the predominant hemicellulosic polysaccharide in cell walls of both species. These findings are in agreement with previous data on cell wall composition reported for Rubiaceae and corroborate the current suggestion of the possible link between this family and Dialypetalanthaceae.RESUMO -(Análise comparativa de polissacarídeos de paredes celulares de folhas de Dialypetalanthus fuscescens e Bathysa meridionalis: evidências de similaridades bioquímicas entre Dialypetalanthaceae e Rubiaceae-Cinchonoideae). Dialypetalanthus fuscescens é uma espécie endêmica da Amazônia com posição taxonômica incerta. Esta espécie da floresta úmida neotropical pertence à família monoespecífica Dialypetalanthaceae. Neste trabalho, foi analisada a composição dos polissacarídeos de paredes celulares de folhas de Dialypetalanthus fuscescens e esta comparada com Bathysa meridionalis (RubiaceaeCinchonoideae). Análises de composição química e ligações glicosídicas demonstraram que ambas as espécies possuem composição química da parede celular bastante similar. Arabinogalactanos foram identificados como os polissacarídeos pécticos predominantes e os xilanos, embora menos freqüentes em dicotiledôneas, foram encontrados em grandes quantidades na fração hemicelulósica de ambas as espécies. Esses resultados estão de acordo com outros previamente reportados para Rubiaceae e constituem uma evidência adicional da possível proximidade taxonômica de Dialypetalanthaceae com Rubiaceae, como atualmente aceito.

show abstract

“…Nonetheless, this author emphasized that further studies on the morphology of this taxonomic group would be needed in order to resolve its systematic position. Piesschaert et al (1997) then described the following taxonomic features of D. fuscescens as having the presence of unitegmic ovules, a nectariferous disk covered by unicellular trichomes, exotestal seeds, and a well-developed endosperm. These characters suggested to the authors that Dialypetalanthus was unrelated to Myrtales.…”

Section: Introductionmentioning

confidence: 99%

“…However, these possible plesiomorphic characteristics would keep this taxon in an isolated position in the family. Despite this profound morphological analysis, Piesschaert et al (1997) still insisted that phytochemical, ontogenetic, and macromolecular studies should be conducted in order to resolve the circumscription of Dialypetalanthus.…”

Section: Introductionmentioning

confidence: 99%

Development of carpels and ovules in Dialypetalanthus fuscescens Kuhlm. (Rubiaceae): an enigmatic taxon

et al. 2017

View full text Add to dashboard Cite

Dialypetalanthus is a monospecifi c genus that occurs in the Amazon Basin of Brazil, Bolivia and Peru and occupies a controversial position among the Rubiaceae. We continue this taxonomic discussion with the overall aim of clarifying the systematic position of D. fuscescens within the Rubiaceae. To accomplish this, we analyzed the ontogeny of its gynoecium, in particular the fl oral meristem, as well as the development of the carpels and cauline placentation. Gynosporogenesis and the diff erentiation of the carpellary septa and ovules were also described. Dialypetalanthus fuscescens was classifi ed according to evolutionary diagrams found in the literature. Th e following characteristics were observed in D. fuscescens: 1) permanence of the fl oral meristem in the central basal part of the early fl ower bud; 2) dual origin of carpellary septum; 3) trizonate ovular primordia with only one fertile gynospore per ovule; and 4) cellular proliferation in the chalazal region. Embryological results confi rm the classifi cation of D. fuscescens in the subfamily Ixoroideae. Th ese results are distinct from any others previously proposed in the evolutionary diagram. Th erefore, we conclude that this study has presented evidence strongly suggesting that Dialypetalanthus possesses new morphological-type of ovule we refer to as the Dialypetalanthus-type.

show abstract

Dialypetalanthus Fuscescens Kuhlm. (Dialypetalanthaceae): The Problematic Taxonomic Position of an Amazonian Endemic

Cited by 18 publications

References 0 publications

Cell wall polysaccharides from cell suspension cultures of the Atlantic Forest tree Rudgea jasminoides (Rubiaceae)

Cell wall polysaccharides from cell suspension cultures of the Atlantic Forest tree Rudgea jasminoides (Rubiaceae)

Comparative analysis of leaf cell-wall polysaccharides of Dialypetalanthus fuscescens and Bathysa meridionalis: evidence of biochemical similarities between Dialypetalanthaceae and Rubiaceae-Cinchonoideae

Development of carpels and ovules in Dialypetalanthus fuscescens Kuhlm. (Rubiaceae): an enigmatic taxon

Contact Info

Product

Resources

About