Navegando por Assunto "Tricomas glandulares"

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Acesso aberto (Open Access)
Estruturas secretoras em cipó-d'alho (Mansoa standleyi (Steyerm.) A. H. Gentry, Bignoniaceae): ocorrência e morfologia
(Instituto Nacional de Pesquisas da Amazônia, 2012-09) POTIGUARA, Raimunda Conceição de Vilhena; DIAS, Ana Cristina Andrade de Aguiar; KIKUCHI, Tatiani Yuriko Souza; SANTOS, Ana Carla Feio dos; SILVA, Rolf Junior Ferreira
Species of Mansoa are called "cipó-d'alho" because of the smell of garlic that wafts from their vegetative and reproductive parts. Since data on the morphology and occurrence of their secretory structures are scarce and even absent for M. standleyi, the present work characterizes the distribution and morphology of such structures in the vegetative aerial axis of the latter. To do so, samples of the leaf blade and of nodal regions were fixed and examined using histological and scanning electron microscope techniques. Histochemical tests with appropriate controls were carried out on the secretory structures during the secretory phase. Fly and ant individuals that visit the species were sampled, preserved and identified by an entomologist. The secretory structures of the vegetative aerial axis of M. standleyi are peltate and patelliform glandular trichomes. All develop asynchronously and are present in the nodal regions and leaf blade, mainly in their youngest parts. Trichomes form a secretory complex in the nodal regions while they are scattered in the leaf blade. Histochemical analyses revealed that the cupulate and patelliform trichomes are extrafloral nectaries and that the peltate ones present an alkaloid fraction. The visitors of the nodal glands are ants Crematogaster (Formicidae) and Ectatomma brunea (Vespoidea, Formicidae) and flies Oxysarcodexia (Sarcophagidae, subfamily Utitidae [Ulidiidae]). The secretory structures of the vegetative aerial axis of Mansoa standleyi are similar to those reported for Bignoniaceae. An extrafloral nectary is described for M. standleyi for the first time.
Acesso aberto (Open Access)
Leaf anatomical features of three Theobroma species (Malvaceae s.l.) native to the Brazilian Amazon
(Instituto Nacional de Pesquisas da Amazônia, 2014-09) GARCIA, Tarcymara Barata; POTIGUARA, Raimunda Conceição de Vilhena; KIKUCHI, Tatiani Yuriko Souza; DEMARCO, Diego; DIAS, Ana Cristina Andrade de Aguiar
Theobroma species have economic importance due to their use in the cosmetic and food industries, mainly in the production of chocolate. However, the anatomy of their vegetative structures remains poorly studied. The goal of this study was to describe the anatomical features of Theobroma grandiflorum, T. speciosum and T. subincanum to contribute to the biological knowledge of these species, as well as provide support to the biotechnological studies of native fruit plants of the Amazon. Leaves at different developmental stages were collected and analyzed under light microscopy and scanning electron microscopy. Sessile and stalked stellate trichomes and digitiform glandular trichomes were observed in the expanded leaves of T. grandiflorum and T. subincanum. These species were also similar in the morphology of the midrib, the organization of the mesophyll and the presence of starch grains in the midrib pith cells. Claviform glandular trichomes and mucilage cells in the epidermis occurred only in the expanded leaves of T. speciosum. The presence of mucilage secretory trichomes in shoot apices (colleters) of all species is a new finding for the genus Theobroma.
Acesso aberto (Open Access)
Transfer cells in trichomatous nectary in Adenocalymma magnificum (Bignoniaceae)
(Universidade Federal do Pará, 2016-01) GAMA, Thália do Socorro Serra; DIAS, Ana Cristina Andrade de Aguiar; DEMARCO, Diego
Transfer cells are specialized cells that play an important role where there are high energy costs due to facilitation of transmembrane flow of solutes. This study aimed to investigate the ontogenesis, histochemistry and ultrastructure of glandular trichomes focusing on stalk cells and their possible transfer function. Samples of prophylls of axillary buds, calyces of flowers in anthesis, and flower buds in different stages of development were collected, fixed and processed according to the common methods of microscopy. The glandular trichomes are composed of a secretory head with its cells in columnar format. The stalk is formed by two layers of cells, with the upper layer composed of cuboidal cells where the wall starts to thicken at the beginning of the pre-secretory phase. The secretion is heterogeneous, releasing glucose, other carbohydrates, lipids and phenolic compounds, with two types of release - eccrine and granulocrine. These trichomes are functionally termed as nectaries. The stalk cells appear as transfer cells since they have a thicker anticlinal wall with irregular ingrowths. The presence of transfer cells in thenectaries suggests a high specialization because it improves transport capacity of nectar and compensation in the high energy expenditure for its production and release.