Atrazine is one of the most used herbicides and has been associated with persistent surface and groundwater contamination, and novel formulations derived from nanotechnology can be a potential solution. We used poly-epsilon caprolactone nano-encapsulation of atrazine (NC+ATZ) to develop a highly effective herbicidal formulation. Detailed structural study of interaction between the formulation and Brassica juncea plants was carried out with evaluation of the foliar uptake of nanoatrazine and structural alterations induced in the leaves. Following postemergent treatment, NC+ATZ adhered to the leaf and penetrated mesophyll tissue mainly through the hydathode regions. NC+ATZ was transported directly through the vascular tissue of the leaves and into the cells where it degraded the chloroplasts resulting in herbicidal activity. Nanocarrier systems, such as the one used in this study, have a great potential for agricultural applications in terms of maintenance of herbicidal activity at low concentrations and a substantial increase in the herbicidal efficacy.

RESUMO -(Análise morfoanatômica comparativa da folha de Bauhinia forficata Link e B. variegata Linn. (Leguminosae, Caesalpinioideae)). Esse trabalho foi desenvolvido com o propósito de subsidiar o controle de qualidade das espécies medicinais Bauhinia forficata Link e B. variegata Linn. Essas foram coletadas em jardins e terrenos baldios de Curitiba, Paraná, Brasil. As amostras do limbo, pecíolo e pulvino foram fixadas em F.A.A. 50 e conservadas em etanol 70%. O seccionamento do material foi feito em micrótomo de rotação (material incluído em historresina) ou a mão livre e as lâminas foram montadas de forma permanente ou semipermanente. Foram realizadas análises em microscopia fotônica e eletrônica de varredura. A folha de B. forficata é alongada, com folíolos unidos em torno da metade do limbo, ápices agudos, superfície adaxial lisa e mucro entre os folíolos. Enquanto que, B. variegata possui folha mais larga que longa, com folíolos unidos na porção terminal do limbo e ápices obtusos. Nos pulvinos de B. variegata ocorrem camadas de colênquima, ausentes em B. forficata. O formato e a bainha de fibras dos pecíolos, em secção transversal, são distintos entre as espécies, assim como a distribuição dos estômatos e tricomas no limbo e a forma do bordo em secção transversal. B. variegata possui maior quantidade de idioblastos com drusas e compostos fenólicos. As características morfológicas e anatômicas de B. forficata e B. variegata contribuem para a identificação e diferenciação das espécies, sendo importantes para o controle de qualidade do material destinado à pesquisa e à indústria farmacêutica. Palavras-chave: Bauhinia, pata-de-vaca, plantas medicinais ABSTRACT -(Comparative morphogical and anatomycal analyses of Bauhinia forficata Link and B. variegata Linn. (Leguminosae, Caesalpinioideae) leaves). This work has been developed with the purpose of helping the quality control of the medicinal speciesBauhinia forficata Link and B. variegata Linn., which were collected in gardens and vacant lots in Curitiba, Paraná, Brazil. The samples of leaf blade, petiole and pulvinus were fixed in FAA 50 and preserved in alcohol 70. The sectioning of the material was made in rotational microtome (with the material included in historesine) or manually and the blades were mounted in permanent or semipermanent way. Analyses in photonic and scanning electronic microscopy were performed. The leaf of B. forficata is elongated, with the leaflets united around the middle of the leaf blade, acute apices, smooth adaxial surface and mucros between the leaflets. The B. variegata, on the other hand, possesses a broader than long leaf, with the leaflets united in the terminal portion of the blade and obtuse apices. In the pulvinus of B. variegata there are collenchyma layers, which are absent in B. forficata. The shape and the petiole fibers sheath, in cross section, are distinct in both species, as well as the distribution of the stomata and trichomes in the leaf blade and the shape of the border in transversal section. B. variegata possess...

Plant adaptation strategies to harsh environments are among the most interesting subjects in plant biology. Several studies have investigated the role trichomes play in protecting plant organs in these conditions. In this work we report an unusual way of protecting the stem apex of Lychnophora diamantinana. The terminal cell of its non-glandular trichomes undergoes partial degradation of the cell wall, producing a highly hydrated, hyaline material that protects the stem apex against desiccation.

The Lychnophorinae subtribe (Asteraceae: Vernonieae) occurs mainly on the Central Brazilian Plateau, especially in areas characterised by intense solar radiation, large daily temperature fluctuations, water scarcity during autumn and winter, and frequent fire. However, a few species of Lychnophorinae, such as Blanchetia heterotricha DC., are not restricted to the Cerrado Domain, but can live in open and humid areas of borders of the Atlantic Forest. To understand the mechanisms of Lychnophorinae adaptation to these environmental conditions, habit, leaf and stem functional traits from 12 species were analysed. Leaf and stem samples were processed and stained using standard plant-anatomy methodology. A comparative analysis of functional groups was performed by principal coordinates analysis, which was applied to two matrices of 30 qualitative and five quantitative traits. The multivariate analysis based on qualitative traits highlighted the following four functional types that might be linked to ecological conditions: Group I adapted at open and humid areas of borders of the Atlantic Forest; Group II, with features mostly related to foggy habitats; Group III, exhibiting traits quite adapted to the seasonally dry and variable conditions of the campos rupestres; and Group IV, showing the most specialised morphological and anatomical traits, which might be related to the extreme conditions of the campos rupestres

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Tribe Vernonieae are well represented in Brazil, mainly by subtribe Lychnophorinae comprising mostly perennial plants that inhabit arid lands, where species have developed a number of adaptations with recognized ecological protective functions, including secondary metabolite diversification. Recent phylogenetic studies indicate that the subtribe is monophyletic, but questions regarding lineage relationships have yet to be resolved. Phytochemical investigations have also been conducted recently and provide information on the secondary metabolite chemistry of Lychnophorinae. Chemotaxonomic studies have also been carried out. However, these phytochemical investigations are fragmentary and non-standardized. Therefore, in this study, 15 species representing the major lineages of the subtribe were selected for phytochemical investigation and reconstruction of the ancestral states of their secondary metabolites. The main secondary metabolites of these species were detected by UHPLC-UV-MS in different types of extract, showing the presence of trans-cinnamic acid derivatives, flavonoids, polyacetylenes and sesquiterpene lactones. The ancestral states of these secondary metabolites were reconstructed by parsimony and indicate the occurrence of 12 putative chemical synapomorphies. In this study, we present for the first time phytochemical and evolutionary studies based on the reconstruction of the ancestral chemical character states on a phylogenetic tree of Lychnophorinae.

Vernonieae are well represented in South America by subtribe Lychnophorinae, with 104 Brazilian species, some of them rare and endangered. Lychnophorinae are well known for producing metabolites of high pharmaceutical and chemotaxonomic value. Despite the importance of secondary metabolites in Lychnophorinae, there is still little evidence regarding the secretory structures responsible for producing these compounds. Therefore, in this study we investigated 15 species representative of the main lineages of Lychnophorinae, with the following objectives: to identify where the chemotaxonomic markers of Lychnophorinae are secreted and stored and in which developmental stage of the organ these metabolites are found. Samples of stems and leaves were processed according to the usual techniques in plant anatomy. It was found that the main sites of secondary metabolite biosynthesis are glandular trichomes, epidermal cells and parenchyma tissues. Metabolites from glandular trichomes, especially sesquiterpene lactones (STL), are prevalent in the early developmental stages of organs. The metabolite compounds stored in parenchyma tissues are mainly terpenoids, flavonoids and other phenolic compounds; young and expanded leaves are equally rich in metabolites. Thus, the information obtained in this study is essential for conducting chemotaxonomic studies in this group, helping to promote selective collection and conservation of species.

Colleters are trichomes or emergencies that produce a sticky exudate consisting of a mixture of mucilage, lipids, terpenes, and phenolic compounds. Colleters occur in at least 60 families of angiosperms; however, reports of them are scarce for the Orchidaceae. Elleanthus brasiliensis is distinguished by the presence of an abundant gelatinous secretion that covers almost all of its inflorescences. We aimed to describe the histology of colleters in inflorescences of E. brasiliensis and Elleanthus crinipes , and to analyze the chemical composition of their secretion to better understand the functions of these secretory structures. Due to the low frequency of colleters and lack of visible secretion in E. crinipes , histochemical tests and chemical analyses were not performed for this species. Colleters are of a brush type and their secretion has, at the same time, hydrophilic and lipophilic components. Histochemical tests further revealed the presence of pectin, mucilage, lipids, terpenes, phenolic compounds, and proteins. The GC-MS analysis confirmed the presence of γ-sitosterol and palmitic, linoleic, and stearic acids in the secretion of E. brasiliensis . Infrared analysis indicated the possible presence of polysaccharides in the secretion. The occurrence of colleters in both species studied and in other orchids described in the literature suggests that these structures are common in the inflorescences of tropical orchids. In these environments, the hydrated polysaccharides in the secretion form a dense matrix that can act as a physical barrier, and terpenes may help to protect against herbivores and pathogenic microorganisms. This information broadens our knowledge of the morphological and chemical diversity of the secretions produced by orchid colleters.