Histopathology of the Shoot Apex of Sugarcane Colonized by Leifsonia xyli subsp. xyli.

Colonization of the xylem of sugarcane by Leifsonia xyli subsp. xyli results in the occlusion of the vessels by a gum-like compound and compromises the elongation of the stalk leading to stunted plants. However, no study has been performed in the apical tissue where the elongation of the stalks initiates at the intercalary meristem (IM). Microscopic and histochemical analyses were performed in plants with lower and higher bacterial titers and revealed that in both cases L. xyli subsp. xyli is present in this tissue and colonizes the forming xylem vessels in a similar way as observed in developed internodes. In both cases, it was observed adhering to the secondary walls, but only in plants with higher titers were a mild degradation of the walls and a granular material filling the vessels observed. The mixed composition of lipids, proteins, and pectin indicates that the filling is not a bacterial extracellular polymeric substance. Plants with higher bacterial populations also presented lower starch content in the ground parenchyma at the node elements, possibly resulting from the reported downregulation of photosynthesis and increased accumulation of phenolics. Their second and third IMs presented fewer cells and reduced expression of genes related to the cell cycle and to the synthesis of ABA in the apical tissue. These results indicate that increased L. xyli subsp. xyli colonization affects the development of the IM, which ultimately would reduce the length of the internodes, resulting in the main symptom of the disease.

Actividad antiproliferativa de Aldama arenaria (Baker) E. E. Schill. & Panero / Antiproliferative activity from Aldama arenaria (Baker) E. E. Schill. & Panero

El extracto de cloroformo (CE) y las fracciones obtenidas de las raíces de Aldama arenaria se evaluaron para determinar su actividad antiproliferativa in vitro contra 10 líneas celulares tumorales humanas [leucemia (K-562), mama (MCF-7), ovario que expresa un fenotipo resistente a múltiples fármacos (NCI/ADR-RES), melanoma (UACC-62), pulmón (NCI-H460), próstata (PC-3), colon (HT29), ovario (OVCAR-3), glioma (U251) y riñón (786-0)]. CE presentó actividad antiproliferativa débil a moderada (log GI50 medio 1.07), mientras que las fracciones 3 y 4, enriquecidas con diterpenos de tipo pimarane [ent-pimara-8 (14), ácido 15-dien-19-oico y ent-8(14),15-pimaradien-3ß-ol], presentaron actividad moderada a potente para la mayoría de las líneas celulares, con un log GI50 medio de 0.62 y 0.59, respectivamente. Los resultados mostraron una acción antiproliferativa in vitro prometedora de las muestras obtenidas de A. arenaria, con los mejores resultados para NCI/ADR-RES, HT29 y OVCAR-3, y valores de TGI que van desde 5.95 a 28.71 µg.mL-1, demostrando que los compuestos de esta clase pueden ser prototipos potenciales para el descubrimiento de nuevos agentes terapéuticos.

Chloroform extract (CE) and fractions obtained from Aldama arenaria roots were evaluated for their in vitro antiproliferative activity against 10 human tumor cell lines [leukemia (K-562), breast (MCF-7), ovary expressing a multidrug-resistant phenotype (NCI/ADR-RES), melanoma (UACC-62), lung (NCI-H460), prostate (PC-3), colon (HT29), ovary (OVCAR-3), glioma (U251), and kidney (786-0)]. CE presented weak to moderate antiproliferative activity (mean log GI50 1.07), whereas fractions 3 and 4, enriched with pimarane-type diterpenes [ent-pimara-8(14),15-dien-19-oic acid and ent-8(14),15-pimaradien-3ß-ol], presented moderate to potent activity for most cell lines, with mean log GI50 of 0.62 and 0.59, respectively. The results showed promising in vitro antiproliferative action of the samples obtained from A. arenaria, with the best results for NCI/ADR-RES, HT29, and OVCAR-3, and TGI values ranging from 5.95 to 28.71 µg.mL-1, demonstrating that compounds of this class may be potential prototypes for the discovery of new therapeutic agents.

Seasonal variation of the essential oil from two Brazilian native Aldama La Llave (Asteraceae) species.

Aldama arenaria and A. robusta are morphologically similar aromatic species that have seasonal development. The yield and chemical composition of essential oils from aerial and underground vegetative organs of these species were compared to verify the production of volatile metabolites in flowering and dormant phases of development and to identify if there are unique compounds for either species. The major compound in the essential oils from A. arenaria leaves was palustrol (16.22%) and for aerial stems was limonene (15.3%), whereas limonene (11.16%) and α-pinene (19.64%) were the major compounds for leaves and aerial stems from A. robusta, respectively. The major compound for the underground organs was α-pinene, in both species and phenological stages. High amounts of diterpenes were found especially for A. arenaria essential oils. Each analyzed species presented unique compounds, which can provide a characteristic chemical profile for both species helping to solve their taxonomic problems. This study characterized for the first time the yield and essential oil composition of A. arenaria and A. robusta, which have medicinal potential, and some of the compounds in their essential oils are unique to each one and may be useful in helping the correct identification of them.

Aerial stem and leaf morphoanatomy of some species of Smilax

This study aimed to describe the morphoanatomy of the aerial vegetative organs of seven Smilax species, used in Brazilian folk medicine. Samples of leaves and stems were fixed with FAA 50, embedded in historesin, sectioned on a rotary microtome, stained and mounted in synthetic resin. Cuticle ornamentation was analyzed with standard scanning electron microscopy. In the frontal view, the walls of the adaxial epidermis are straight in S. brasiliensis, S. cissoides, S. goyazana and sinuous in the other species. The walls of the epidermis on the abaxial surface are straight in S. brasiliensis, S. goyazana, S. rufescens, sinuous in S. campestris, S. fluminensis, S. oblongifolia, and wavy in S. cissoides. The stomata are paracytic in S. brasiliensis, S. goyazana, S. oblongifolia, and S. rufescens, anomocytic in S. cissoides, S. campestris; anisocytic and paracytic in S. fluminensis. The midrib has three vascular bundles that are individually wrapped by lignified cells in S. brasiliensis, S. cissoides, and S. fluminensis. In the other, the three vascular bundles are surrounded by a single lignified sheath. In the stems the vascular cylinder is surrounded by a sclerenchymatous ring with the exception of Smilax fluminensis, which has a starch sheath and internal layers of thin-walled cells.

Development and characterization of microsatellite markers for the medicinal plant Smilax brasiliensis (Smilacaceae) and related species.

PREMISE OF THE STUDY: A new set of microsatellite or simple sequence repeat (SSR) markers were developed for Smilax brasiliensis, which is popularly known as sarsaparilla and used in folk medicine as a tonic, antirheumatic, and antisyphilitic. Smilax brasiliensis is sold in Brazilian pharmacies, and its origin and effectiveness are not subject to quality control. • METHODS AND RESULTS: Using a protocol for genomic library enrichment, primer pairs were developed for 26 microsatellite loci and validated in 17 accessions of S. brasiliensis. Thirteen loci were polymorphic and four were monomorphic. The primers successfully amplified alleles in the congeners S. campestris, S. cissoides, S. fluminensis, S. goyazana, S. polyantha, S. quinquenervia, S. rufescens, S. subsessiliflora, and S. syphilitica. • CONCLUSIONS: The new SSR markers described herein are informative tools for genetic diversity and gene flow studies in S. brasiliensis and several congeners.

Germination and seedling morphology of four South American Smilax (Smilacaceae)

Species of Smilax, also known as greenbrier, are widely distributed in Brazil and their commercial trades are carried out by the extractivism of native species. We the aim to provide information about the germination and development of seedlings in four Smilax species, different experiments were developed under controlled conditions. We evaluated two germination treatments: temperature (30ºC and 20-30ºC) and light (presence/ absence), and for few cases the tetrazolium treatment was applied. A different treatment response was observed among the studied species. Light had a significant influence in S. brasiliensis, with the highest germination rates at 20-30ºC in dark conditions. S. campestris showed significant differences among temperature treatments, but not to light; while S. cissoides showed high germination rates (66-78%), independently of treatment. However, S. polyantha had low germination rates (19-24%). After one year, the expanded leaves showed different characteristics among the studied species. Leaves of S. brasiliensis were ovate, coriaceous, three main veins and prickle-like structures only on the midrib on abaxial face. S. campestris leaves were oblong, coriaceous and prickle-like structures were located at the leaf midrib and margin. S. cissoides had ovate-elliptic, membranaceous leaves, with three main veins with prickle-like structures on the abaxial face. S. polyantha leaves showed ovateelliptic, coriaceous leaves, with three main veins, translucent secondary veins and no prickle-like structures. A seedling identification key was elaborated based on morphological characteristics.

Propagation studies in Smilax fluminensis Steud. (Smilacaceae) / Estudos de propagação em Smilax fluminensis Steud. (Smilacaceae)

Smilax L. species, popularly known in Brazil as salsaparrilha, have been used in folk medicine as tonic against rheumatism and as anti-syphilitic since the sixteenth century; however, until today, their roots have been explored in an extractive way. The aim of this study was to analyze the propagation of Smilax fluminensis aiming to meet the demand and to propose procedures for its sustainable management. It was analyzed the percentage of seed germination, rooting of aerial and subterranean stem cuttings and plant resprouting capacity after removal of the shoots. The monitoring lasted one year. Seeds were subjected to temperatures: 25°C, 30°C, 20-30°C and 20-35°C under a daily photoperiod of eight hours and in the absence of light. For rooting the stem cuttings, aerial and subterranean stems about 20cm long with two nodal regions were subjected to treatment with distilled water (control) and indolbutyric acid (IBA) at 100ppm. The best germination percentages obtained for S. fluminensis were 80 percent at 20-30°C under light and 85 percent at 30°C in the dark. Only subterranean stem cuttings showed significant difference concerning fresh and dry matter of roots with higher values in treatments with hormone compared to the control.

As espécies do gênero Smilax L., conhecidas popularmente como salsaparrilha, são empregadas na medicina popular como fortificante contra o reumatismo e antissifilítico desde o século XVI, porém até hoje as suas raízes são exploradas de maneira extrativista. O objetivo deste estudo foi analisar a propagação de Smilax fluminensis visando a auxiliar no atendimento da demanda e apontar propostas para o seu manejo sustentável. Foram analisados a porcentagem de germinação de sementes, o enraizamento de estacas de ramos aéreos e subterrâneos e o acompanhamento ao longo de um ano da capacidade de rebrotamento das plantas após a retirada dos ramos aéreos. As sementes foram submetidas às temperaturas: 25, 30, 20-30 e 20-35°C, sob fotoperíodo diário de oito horas e na ausência de luz. Para o enraizamento de estacas, foram utilizados ramos aéreos e subterrâneos com aproximadamente 20cm com duas regiões nodais submetidas ao tratamento com água destilada (controle) e com ácido indolbutírico (AIB) a 100ppm. As melhores porcentagens de germinação obtidas para S. fluminensis, 80 por cento em 20-30°C no claro e 85 por cento a 30°C no escuro. Apenas as estacas de ramos subterrâneos enraizaram, houve diferença significativa em relação à massa fresca e seca de raízes com valores maiores nos tratamentos com hormônio em relação ao controle.