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Item Morphoanatomy of nectaries of Chamaecrista (L.) Moench sections Chamaecrista, Caliciopsis and Xerocalyx (Leguminosae: Caesalpinioideae)(Acta Botanica Brasilica, 2017-07) Silva, Marinalva dos Santos; Coutinho, Ítalo Antônio Cotta; Araújo, Maicon Nascimento; Meira, Renata Maria Strozi AlvesNectaries are specialized structures that secrete nectar. Several species of Chamaecrista possess nectaries on the petiole, which have been shown to vary widely in morphology and the chemical nature of their secretion. However, a comprehensive investigation of the nectaries of the clade formed by sect. Chamaecrista, Caliciopsis and Xerocalyx has yet to be performed. Our study aimed to confirm whether or not the leaf glands of species of this clade are in fact nectaries, determine the chemical nature of their secretion and expand the morphoanatomical database on leaf nectaries in Chamaecrista with the intention of contributing to the taxonomy and phylogeny of the genus. Samples from herbarium and field-collected material were subjected to standard methods for light and scanning electron microscopy. Four different forms of nectaries were observed: urceolate, patelliform, verruciform and cupuliform. The nectaries were found to comprise a single-layered epidermis, nectary parenchyma, subnectary parenchyma and vascularization. Polysaccharides, lipids, phenolic compounds and proteins were detected in secretions. Although anatomical similarities were observed among the studied species, their morphology differed. Moreover, the glands are indeed nectaries and are similar to those observed in other species of the genus Chamaecrista. These data hold potential taxonomic usefulness for the studied sections.Item Extrafloral nectaries of annatto ( Bixa orellana L.): anatomy, nectar composition and activity during organ development(Acta Botanica Brasilica, 2017-07) Miranda, Rafaela Marques de; Nery, Lays Araújo; Ventrella, Marília ContinThis study aimed to anatomically characterize the extrafloral nectaries (EFNs) of annatto (Bixa orellana) and determine the composition of its nectar in order to better understand their structure and function during organ development. Standard light and scanning electron microscopy techniques were used for anatomical analysis, and test-strips and a refractometer for determining nectar composition. Both receptacle and stem EFNs were found to possess similar anatomy and nectar composition, and to secrete from early to advanced developmental stages of the organs to which they are associated. EFNs consisting of uniseriate epidermis, nectariferous parenchyma and subnectariferous parenchyma were found located where vascular tissue is immersed. Some layers of nectariferous parenchyma exhibited sclerification and cells with phenolic compounds or calcium oxalate druses were present. Nectar exuded by stomata was acidic, diluted and found to contain sugar. The anatomical and histochemical features of annatto EFNs ensure their integrity and nectar secretion function during the development of buds, flowers and fruits.Item Anatomy of the floral, bract, and foliar nectaries of Triumfetta semitriloba (Tiliaceae)(Canadian Journal of Botany, 2005) Meira, Renata Maria Strozi Alves; Azevedo, Aristéa Alves; Araújo, João Marcos de; Silva, Kellen Lagares Ferreira; Leitão, Carlos André Espolador; Collevatti, Rosane GarciaTriumfetta semitriloba Jacq. (Tiliaceae) is a tropical weedy species with floral nectaries and glands located at the margins of the leaves. The objectives of this work were to describe the anatomy of these secretory structures and to analyze their exudates. Sucrose, glucose, and fructose were identified in the product released by these secretory structures, characterizing them as nectaries. The nectaries of T. semitriloba are of a specialized type; a secretory epidermis comprised of pluricellular and multiserial nectariferous trichomes covers a nectariferous parenchyma, vascularized by phloem and xylem. A mass of phenolic compounds occurs in the head cells of the nectariferous trichomes of the foliar and bract nectaries; however, it is absent in trichomes of the floral nectary. The leaf and bract nectaries differed from those from flowers in their length and diameter. Structural features of the nectaries of T. semitriloba are typical of other taxa of the Malvales.Item Structural diversity of extrafloral nectaries in Chamaecrista sect. Apoucouita(Botany, 2015) Coutinho, Ítalo Antônio Cotta; Meira, Renata Maria Strozi AlvesSection Apoucouita (Chamaecrista (L.) Moench – Caesalpinioideae) is an arboreal group that is most diverse in the Amazon and Brazilian Atlantic forests. These species typically bear petiolar and (or) rachis glands called extrafloral nectaries (EFNs). However, no detailed anatomical studies or histochemical analyses have been conducted to confirm nectar secretion. We aimed at describing the structure of such EFNs, as well as determining the chemical nature of the secretion. Eighteen species (23 taxa) were studied using standard light microscopy techniques. We describe 13 types of EFNs with variable morphology. Such EFNs may be impressed, sessile, or stalked; with concave, flat or truncate, or convex secretory surfaces. Cupuliform EFNs (stalked or not) were the most common type observed and patelliform the least common. Despite the morphological variation, differences in the anatomical structure of the EFNs and the chemical composition of the secretion were not observed. EFNs with concave secretory surfaces appear to be more effective as nectar may become accumulated in the concavity, increasing the volume of available nectar. Our results show that despite the variable morphology of the EFNs, such structures share similarities on the anatomy and composition of the secretion and development of a wound-healing periderm in older EFNs. We also indicate the importance of including the morphological variation observed in the EFNs in species of sect. Apoucouita in future taxonomic evaluations.Item Colleters in 10 species belonging to three tribes of Rubiaceae: morphoanatomical diversity and potential as useful characters for taxonomy(Botany, 2015-07) Otuki, Sara Akemi Ponce; Azevedo, Aristéa Alves; Pereira, Zefa Valdivina; Meira, Renata Maria Strozi Alves; Lopes-Mattos, Karina Lucas BarbosaColleters are common secretory structures in Rubiaceae. In this study, we describe colleter morphoanatomy and histochemistry in 10 species belonging to Chiococceae, Coussareae, and Psychotrieae tribes of Rubiaceae. Colleter morphoanatomy was analyzed by light and scanning electron microscopy. Microscopy analysis revealed that colleters were present on the stipule adaxial surface in all species. In the case of Palicourea marcgravii A.St.-Hil. and Chiococca alba Hitchc., colleters were also found on leaf primordia and at the stipule apex, respectively. Colleters were classified into three types: standard, bifurcated standard, and reduced standard. Further analysis showed that colleter epidermal cells are thin-walled and possess a thin cuticle, conspicuous nuclei located at the equatorial or basal region, and abundant cytoplasm. Intercellular spaces were found among epidermal cells in Chiococca alba, Coussarea triflora Müll.Arg., Coussarea verticillata Müll.Arg., Psychotria conjungens Müll.Arg., and Psychotria sessilis Vell. Crystalliferous idioblasts containing raphides were observed in the colleter central parenchymatous axis of all species, while crystal sand was found only in Chiococca alba. Histochemical tests revealed that colleter secretion is composed of a mixture of mucilage and protein. We conclude that colleter position, typological variation, presence of vascularization, and type of calcium oxalate crystals represent promising characters for future taxonomic and phylogenetic studies in Rubiaceae.Item Anatomy of the extrafloral nectaries in species of Chamaecrista section Absus subsection Baseophyllum (Leguminosae, Caesalpinioideae)(Flora - Morphology, Distribution, Functional Ecology of Plants, 2012-06) Coutinho, Ítalo Antônio Cotta; Francino, Dayana Maria Teodoro; Azevedo, Aristéa Alves; Meira, Renata Maria Strozi AlvesIn this paper the ontogenesis and histochemistry of the petiolar glands found on the petiole/rachis of the eight Chamaecrista species of the section Absus, subsection Baseophyllum (Leguminosae, Caesalpinioideae) are studied by using light microscopy techniques, aiming to characterise these structures and to provide taxonomic characters which may be useful in phylogenetic approaches. Strips for glucose identification reacted positively with the exudates of the glands, confirming the presence of nectar in the secretion, characterising these glands as extrafloral nectaries (EFN). Histochemical tests also detected the presence of neutral and acid muco-polysaccharides, pectins, mucilages, total proteins, and phenolic compounds in the EFNs. The EFNs arise from a group of meristem cells (protodermis, ground meristem and procambium) in the petiole/rachis. All EFNs of the investigated taxa share some morpho-anatomical characters, so that their peculiarities are too weak to be used alone in the identification of particular species. Rather their similarities may be used to include these species into a single group, supporting the hypothesis of monophyly of the subsection Baseophyllum.Item Secretory cells in Piper umbellatum (Piperaceae) leaves: a new example for the development of idioblasts(Flora - Morphology, Distribution, Functional Ecology of Plants, 2011-12) Marinho, Cristina Ribeiro; Zacaro, Adilson Ariza; Ventrella, Marília ContinThis work aims to investigate the origins and development of secretory cells in Piper umbellatum (L.) Miq. (Piperaceae) leaves as well as the course and the nature of their secretion. The results were compared with studies in oil-secreting cells of several species. Fully expanded fresh leaves were sectioned and subjected to different histochemical tests. Leaves in different developmental stages were fixed and processed for study under light and scanning and transmission electron microscopy techniques. The secretory cells show mixed secretion made up of hydrophobic (oleoresin) and hydrophilic (phenolic compounds and alkaloids) compounds. Secretory cells originate either from the protodermis or the ground meristem. The growth of these cells occurs primarily by increasing the volume of the central vacuole, which corresponds to an extraplasmatic space connected to a protuberance of the wall. Electron-opaque compounds are observed initially in leucoplasts, while electron-dense compounds occur in small vesicles in the cytoplasm. Both are accumulated in the central vacuole which is already developed. Besides the mixed chemical nature of the secretion identified in secretory cells of P. umbellatum leaves, these secretory cells differ from those that have already been described mainly because of the development of the central vacuole prior to the accumulation of the secretion.Item Colleters in Bathysa cuspidata (Rubiaceae): Development, ultrastructure and chemical composition of the secretion(Flora - Morphology, Distribution, Functional Ecology of Plants, 2013-12) Coelho, Victor Peçanha de Miranda; Leite, João Paulo Viana; Fietto, Luciano Gomes; Ventrella, Marília ContinThis paper describes the development of colleters of Bathysa cuspidata, Rubiaceae, considering anatomical, histochemical and ultrastructural aspects and going from first differentiation stages until senescence. Further, the chemical composition of the secretion is investigated. The samples were prepared according to the usual techniques for light microscopy and scanning and transmission electron microscopy. Electrophoresis and thin layer chromatography (TLC) were used to confirm the results obtained in the histochemical tests. The colleters occur at the ventral surface of the stipules which protect the leaf primordia as well as the shoot meristem. The origin of the colleters is mixed, involving protoderm and ground meristem. The Bathysa colleters are of the standard type or are bifurcated; this latter type is documented here for the first time for Rubiaceae. Colleter secretion is a mucilage rich in protein, as determined by histochemical tests and confirmed by chemical analysis. Phenolic compounds and terpenes were detected only in the colleters themselves, but not in the secretion. The epithelial cells present conspicuous nuclei and nucleoli and the cytoplasm is rich in dictyosomes, endoplasmic reticulum, mitochondria, vesicles and small vacuoles with a fibrillar content. The accumulation of phenolic compounds and terpenes, the formation of a large central vacuole, the increase of the intercellular and subcuticular spaces occupied by the secretion and, finally, the darkening and the wilting of the colleters characterize the senescence of these structures. The secretion process of the colleters of B. cuspidata suggests a process of programmed cell death.Item Anatomical and histochemical characterization of extrafloral nectaries of Prockia crucis (Salicaceae)(American Journal of Botany, 2008-12-01) Thadeo, Marcela; Cassino, Mariana F.; Vitarelli, Narah C.; Azevedo, Aristéa A.; Araújo, João M.; Valente, Vânia M. M.; Meira, Renata M. S. A.Besides being vital tools in taxonomic evaluation, the anatomy of plant secretory structures and the chemical composition of their secretions may contribute to a more thorough understanding of the roles and functions of these secretory structures. Here we used standard techniques for plant anatomy and histochemistry to examine secretory structures on leaves at different stages of development of Prockia crucis, to evaluate the origin and development of the structures, and to identify the disaccharides and monosaccharides in the exudates. Fructose, glucose, and sucrose constituted up to 49.6% of the entire secretion. The glands were confirmed to be extrafloral nectaries (EFNs); this is the first report of their presence in the genus Prockia. These EFNs are globular, sessile glands, with a central concavity occurring on the basal and marginal regions of the leaf. The epidermis surrounding the concavity is secretory, forming a single‐layered palisade that strongly reacts with periodic acid–Schiff's reagent (PAS) and xylidine Ponceau, indicators of total polysaccharides and total proteins, respectively, in the exudate. On the basis of the similarity of these glands to the salicoid teeth in Populus and Salix, we suggest that these three taxa are phylogenetically close.Item Anatomy of vegetative organs of Scutellaria agrestis, a medicinal plant cultivated by riverine populations of the Brazilian Amazon(Revista Brasileira de Farmacognosia, 2013-03-20) Meira, Renata M. S. A.; Mendonça, Maria S. de; Oliveira, Andréia B. deScutellaria agrestis A. St. -Hil. ex Benth. , Lamiaceae (trevo-roxo) is cultivated for medicinal purposes by residents of the riverine communities in the State of Amazonas, Brazil. This study aimed to characterize the anatomy and to make histochemical analysis on vegetative organs of S. agrestis. Samples of the leaf, stem and root were collected from five plants cultivated by the communities located in the Solimões river, Amazon. These samples were fixed and prepared following standard techniques for scanning electron microscopy and for light microscopy. Histochemical tests were carried out on sections to detect the main classes of compounds present in the secretion. Numerous glandular trichomes are seen in both leaf and stem of S. agrestis. The leaves are amphi-hypostomatics and show dorsiventral mesophyll. Hydathodes are present at the tip of the marginal teeth. Anthocyanin pigments occur into the epidermal cells of the stem, petiole, and abaxial leaf surface. The petiole is concave-convex shaped and bears collateral vascular bundles. The stem showed square-shaped, evident endoderm, collateral vascular bundles and parenchymatous pith. The root displays a typical protostelic structure. Idioblasts containing mucilage and phenolic compounds occur in the cortex. These data are important, as they can be useful to identify this species, contributing to the quality control of the medicinal plant