Foliar anatomy from species of Flacourtiaceae (Sleumer 1980)

Não existe consenso quanto à organização taxonômica das Flacourtiaceae e na literatura o assunto é pouco enfatizado, pois são escassos os trabalhos de revisão taxonômica realizados. Diversos autores ressaltam a íntima relação entre a família Flacourtiaceae e a Salicaceae. Numerosas são as famílias de plantas com representantes medicinais, destacando-se, entre elas, a Flacourtiaceae, principalmente os gêneros Casearia e Carpotroche. Extensivas investigações têm enfatizado as propriedades terapêuticas das espécies de Casearia, propriedades estas relacionadas com compostos secretados por estruturas especializadas presentes nas folhas. O estudo da composição química do material secretado pelas estruturas secretoras, juntamente com a anatomia dessas estruturas, pode contribuir para a compreensão do exato papel e da função do produto secretado para a planta, além de poder ser um componente importante para as avaliações taxonômicas. Considerando a importância da anatomia como subsídio para a taxonomia, dados sobre a família são fundamentais para auxiliar na elucidação dos problemas taxonômicos. Este trabalho teve como objetivos: caracterizar anatomicamente as folhas de espécies de Abatia, Banara, Carpotroche, Casearia, Prockia e Xylosma ocorrentes em fragmentos florestais da Zona da Mata de Minas Gerais e avaliar a importância dos caracteres anatômicos como subsídio para a identificação das espécies; caracterizar anatômica e histoquimicamente as estruturas secretoras que ocorrem nas folhas de Prockia crucis e Casearia decandra; correlacionando com a composição química do produto secretado pela primeira espécie citada; descrever a micromorfologia e anatomia das glândulas secretoras de Prockia crucis. Folhas de representantes dos gêneros Abatia, Banara, Carpotroche, Casearia, Prockia e Xylosma foram coletadas em três fragmentos florestais do município de Viçosa (MG) e num campo de altitude no Parque Estadual da Serra do Brigadeiro (MG), e submetidos à técnicas usuais em anatomia vegetal, sendo Casearia decandra e Prockia crucis submetidas à testes histoquímicos. Foram descritas anatomicamente onze espécies, ressaltando-se as diferenças e semelhanças entre as mesmas. Neste trabalho foi possível constatar alguns caracteres que podem agir de forma unificadora para a família Flacourtiaceae e a Salicaceae: presença do dente salicóide, tricomas simples unicelulares e não ramificados, tricomas multicelulares e ramificados, estômatos braquiparacíticos, crescimento secundário no pecíolo, abundância de cristais, sistema vascular colateral e em forma de arco na nervura mediana, mesofilo dorsiventral e esclerênquima acompanhando os feixes. Os estudos anatômicos feitos nas espécies de Flacourtiaceae demonstraram que a anatomia foliar pode fornecer dados para auxiliar na taxonomia da família, tanto a nível genérico como específico. O sistema secretor de C. decandra é composto por ductos e cavidades dispersos pela lâmina foliar e pecíolo, e por idioblastos presentes nos tecidos vasculares, parênquima cortical da nervura mediana e no parênquima paliçádico. Os ductos encontram-se distribuídos no parênquima cortical da nervura e possuem continuidade nesta mesma região do pecíolo. No mesofilo existem numerosas cavidades com localização subepidérmica ou distribuídas na interface do parênquima paliçádico com o lacunoso. Detectaram-se substâncias lipofílicas e hidrofílicas, evidenciando lipídios do tipo óleo-resina nos ductos e cavidades, e compostos fenólicos do tipo tanino nos idioblastos e no parênquima. Não foram detectados alcalóides, polissacarídeos e proteínas. Este trabalho relatou a presença de ductos e cavidades para o gênero Casearia. Os testes histoquímicos confirmam a complexidade do secretado, além de indicar tecidos fundamentais como sítios de síntese e/ou acúmulo de compostos fenólicos. Na secreção das estruturas secretoras de Prockia crucis foram detectadas frutose, glicose e sacarose e a concentração de açúcares equivale a 49,6% do total do secretado. As glândulas foram identificadas como nectários extraflorais (NEFs), sendo esse o primeiro relato da sua presença para o gênero. O néctar produzido possui alto valor energético. Os NEFs ocorrem nas regiões basais e marginais da folha, são sésseis, circulares e com uma concavidade central. A epiderme que recobre a concavidade é secretora, uniestratificada, formando uma paliçada de células que reagiram fortemente ao Reativo de Schiff e ao Xilidine Ponceau, evidenciando polissacarídeos neutros e proteínas, respectivamente. O parênquima nectarífero possui algumas células com citoplasma granuloso que reagiram ao teste para compostos fenólicos. Esse parênquima é interrompido pelas extensões vasculares que se ramificam. O desenvolvimento dos nectários se inicia muito precocemente, já nos primórdios foliares do meristema apical, estando totalmente diferenciado em folhas ainda em expansão. Devido à sua similaridade com os dentes salicóides presentes em Populus e Salix, sugere-se que tais clados sejam próximos filogeneticamente.There is no agreement regarding the taxonomic organization of the Flacourtiaceae and the theme is not emphasized in the literature, since there is a lack of taxonomic studies on this family. Several authors point out the close relationship between the families Flacourtiaceae and Salicaceae. Numerous families of plants have members with medicinal uses, standing out among them the Flacourtiaceae, mainly the genera Casearia and Carpotroche. Extensive investigations have emphasized the therapeutic properties of Casearia species related with compounds secreted by specialized structures in the leaves. The study of the chemical composition of secretory products together with anatomic studies of secretory structures can contribute to understand the role and function of these products in the plant, besides being an important component for taxonomic evaluations. Considering the importance of anatomy as subsidy for taxonomy, family data are fundamental to elucidate taxonomic problems. The objectives of this work were to characterize anatomically leaves of Abatia, Banara, Carpotroche, Casearia, Prockia and Xylosma species occurring in forest fragments of Zona da Mata - Minas Gerais and to evaluate the importance of anatomical characters for species identification; to characterize anatomical and histochemically secretory structures present in leaves of Prockia crucis and Casearia decandra, correlating with the chemical composition of the product secreted by the former; to describe the micromorphology and anatomy of Prockia crucis secretory glands. Leaves of members of the genera Abatia, Banara, Carpotroche, Casearia, Prockia and Xylosma were collected from three forest fragments in the municipality of Viçosa (MG) and from an altitude field in the Serra do Brigadeiro State Park (MG) and subjected to usual techniques used in plant anatomy. Casearia decandra and Prockia crucis were also histochemically tested. Eleven species were anatomically described, giving emphasis on their differences and similarities. In this work, it was possible to confirm some unifying characters for the families Flacourtiaceae and Salicaceae such as the presence of salicoid leaf teeth, simple unbranched unicellular trichomes, branched multicellular trichomes, brachyparacitic stomata, secondary growth of the petiole, crystal abundance, collateral and arch-shaped vascular system at the midrib, dorsiventral mesophyll and sclerenchyma accompanying the bundles. The anatomic studies carried out on Flacourtiaceae species demonstrated that leaf anatomy can provide data to assist in the family taxonomy, at both generic and specific levels. The secretory system of C. decandra consists of ducts and cavities dispersed on the leaf lamina and petiole and idioblasts present in the vascular tissues, cortical parenchyma of the midrib and in the palisade parenchyma. The ducts are distributed in the cortical parenchyma of the rib and continue in this same region of the petiole. In the mesophyll there are numerous cavities in the subepidermic layer or distributed in the interface between the palisade and spongy parenchyma. Lipophilic and hydrophilic substances were detected, confirming oil-resin lipids within ducts and cavities, and phenolic compounds, of the tannin type, within idioblasts and parenchyma. Alkaloids, polysaccharides and proteins were not detected. This work reported the presence of ducts and cavities for the genus Casearia. Histochemical tests confirm the secretory product complexity, besides indicating fundamental tissues such as sites of synthesis and/or accumulation of phenolic compounds. Fructose, glucose and sucrose were detected in the product of secretory structures of Prockia cruces, with sugar concentration being 49.6% of the total secretory product. Glands were identified as extrafloral nectaries (EFNs), which is the first report of their presence in the genus. The produced nectar has a high energy value. EFNs occur in the basal and marginal regions of the leaf, they are sessile, circular and have a central concavity. The epidermis covering the concavity is secretory, unistratified, forming a palisade layer of cells that reacted strongly positively after staining with Schiff s reagent and Xylidine Ponceau, confirming neutral polysaccharides and proteins, respectively. The nectary parenchyma presented cells with granular cytoplasm that reacted to the test for phenolic compounds. This parenchyma is interrupted by vascular extensions which ramify. The development of nectaries begins very early, in the leaf primordiums of the apical meristem, being totally differentiated in the expanding leaves. Due to their similarity with the salicoid leaf teeth present in Populus and Salix, it is suggested that such clades are phylogenetically close.Coordenação de Aperfeiçoamento de Pessoal de Nível Superio

Preparation of Samples for Leaf Architecture Studies, A Method for Mounting Cleared Leaves

Premise of the study: Several recent waves of interest in leaf architecture have shown an expanding range of approaches and applications across a number of disciplines. Despite this increased interest, examination of existing archives of cleared and mounted leaves shows that current methods for mounting, in particular, yield unsatisfactory results and deterioration of samples over relatively short periods. Although techniques for clearing and staining leaves are numerous, published techniques for mounting leaves are scarce. Methods and Results: Here we present a complete protocol and recommendations for clearing, staining, and imaging leaves, and, most importantly, a method to permanently mount cleared leaves. Conclusions: The mounting protocol is faster than other methods, inexpensive, and straightforward; moreover, it yields clear and permanent samples that can easily be imaged, scanned, and stored. Specimens mounted with this method preserve well, with leaves that were mounted more than 35 years ago showing no signs of bubbling or discoloration

Foliar anatomy of neotropical Salicaceae: potentially useful characters for taxonomy

The taxonomy of neotropical Salicaceae, a family that now includes the majority of the former Flacourtiaceae, has been problematic, especially because they display very diverse morphology and have several characteristics in common with many other families. Recent phylogenetic studies have proposed substantial changes at both family and generic levels. Considering the importance of anatomy as an aid for taxonomy, the gathering of anatomical data for the family is fundamental to help clarify the taxonomic problems. Leaves belonging to Abatia americana (four samples), Banara brasiliensis (2), Casearia arborea (4), C. decandra (5), C. gossypiosperma (2), C. obliqua (1), C. sylvestris (3), C. ulmifolia (3), Prockia crucis (3), and Xylosma prockia (4) and the closely related Carpotroche brasiliensis (3) from Achariaceae, were studied by standard microscopy techniques. The leaves were anatomically described, emphasizing their differences and similarities. Similar characters for the neotropical Salicaceae (former Flacourtiaceae) and Salicaceae strictu sensu were recognized, such as the presence of salicoid leaf teeth, brachyparacytic stomata, secondary growth of the petiole, abundance of crystals, collateral and arch-shaped vascular system at the midrib, and sclerenchyma accompanying the bundles. These data demonstrate that leaf anatomy can provide evidence to assist with the taxonomy of Salicaceae, at family, generic, and specific levels

Anatomia e histoquímica das estruturas secretoras do caule de Spondias dulcis Forst. F. (Anacardiaceae)

Spondias dulcis Forst. F. vem recebendo atenção especial por secretar uma goma que possui ação medicinal. Em outras espécies de Anacardiaceae, a maioria dos estudos sobre as estruturas secretoras refere-se à ultra-estrutura e desenvolvimento dos ductos, existindo poucas informações quanto à natureza química do secretado. O objetivo do presente trabalho foi caracterizar estrutural e histoquimicamente o sistema secretor do caule de S. dulcis. Amostras do caule jovem de plantas com 45 dias de idade foram submetidas às técnicas usuais em anatomia vegetal e a testes histoquímicos. O sistema secretor de S. dulcis apresenta ductos e idioblastos. Os ductos, muito longos, encontram-se associados ao floema e na medula, enquanto os idioblastos ocorrem no córtex e, também, associados ao floema. Os ductos apresentam um epitélio secretor unisseriado, formado por células cuneiformes a tabulares, de paredes delgadas, citoplasma denso e núcleo volumoso com nucléolo proeminente. Nos ductos associados ao floema, observam-se, externamente ao epitélio, duas a três camadas de células parenquimáticas, achatadas e dispostas radialmente, formando uma bainha. Os testes histoquímicos evidenciaram a presença de taninos nos idioblastos corticais. A secreção dos ductos é constituída, em sua maioria, por óleos essenciais, polissacarídeos e compostos fenólicos (provavelmente agliconas flavonóicas), o que permite caracterizá-la como uma gomorresina

Foliar anatomy and histochemistry in seven species of Eucalyptus

This work aimed to describe the foliar anatomy of seven species of Eucalyptus, emphasizing the characterization of secretory structures and the chemical nature of the compounds secreted and /or present in the leaves. Anatomical characterization and histochemical evaluation to determine the nature and localization of the secondary compounds were carried out in fully expanded leaves, according to standard methodology. Anatomical differences were verified among the species studied, especially in E. pyrocarpa. Sub-epidermal cavities were the only secretory structures found in the seven species studied, with higher density in E. pellita and lower in E. pilularis. The following compounds were histochemically detected: lipophilic compounds, specifically lipids of the essential or resin-oil type and sesquiterpene lactones found in the lumen of the cavities of the seven species; and hydrophilic compounds, of the phenolic compound type found in the mesophyll of all the species studied and on the epidermis of some of them. The results confirmed the complexity of the product secreted by the cavities, stressing the homogeneous histochemistry nature of these compounds among the species. However, the phenolic compounds results may be an indication of important variations in adaptations and ecological relations, since they show differences among the species

Anatomical and histochemical characterization of extrafloral nectaries of Prockia crucis (Salicaceae)

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