Morfologia e anatomia de Paspalum L. (Poaceae, Poales) e suas implicações taxonômicas

Pós-graduação em Ciências Biológicas (Biologia Vegetal) - IBRC

A dehydrorotenoid produced by callus tissue culture and wild plant roots of Boerhaavia coccinea

“Um desidro-rotenóide produzido por cultura de calos e por raízes de plantas silvestres de Boerhaavia coccinea”. Cultura de calos foram estabelecidos de folhas e galhos finos de plântula de B. coccinea produzida in vitro e analisada para isofl avonóide. A quantificação do 6,9,11-triidroxi-6a,12a-desidro-rotenóide isolado das raízes de B. coccinea P Miller, coletada em seu habitat natural, e do mesmo rotenóide produzido na cultura de células estão descritos neste artigo. A análise rotineira em CLAE mostrou que a cultura de calos produziu o mesmo isoflavonóide encontrado nas raízes da planta do campo. A quantidade do metabólito secundário produzido in vitro foi de 955.35

Estudo da diversidade agrícola de raízes e tubérculos em assentamentos rurais no interior paulista

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Resorption of roots of different dimension induced by different types of forces

Root resorption is a variable to be considered in induced tooth movement (ITM). It is related to root morphology and alveolar bone crest, and also to the types of forces exerted by mechanotherapy. This histometric study evaluated the predominance of root resorption among roots of different dimensions, following ITM with different types of forces and at different time intervals. The study was conducted on 54 rats divided into three groups, according to the type of force: continuous (CF), continuous interrupted (CIF) and intermittent (IF), at periods of 5, 7 and 9 days. The percentage of resorption between mesiobuccal roots of larger dimension and intermediate roots of smaller dimension was assessed. The evaluations were performed on the AxioVision software, and the non-parametric analysis of variance for repeated measures in independent groups was further applied, consisting of a scheme of two factors, and complemented by the Dunn test at a significance level of 5%. The intermediate roots presented a higher percentage of resorption, which was gradual at the periods evaluated for the three types of forces, but mainly for CF. Comparing the intermediate roots with the mesiobuccal roots, there was a statistically significant difference (p < 0.05) in the CF group at day 7 and day 9, and in the FI group, at day 9. The intragroup analysis evidenced a statistically significant difference (p < 0.05) between the 5th and the 9th day for the intermediate root in the CF group. The intergroup analysis did not reveal any statistically significant difference (p > 0.05) in individually analyzed roots.

Osseointegration at implants placed into delayed reimplanted roots: An experimental study in dogs

AimTo evaluate peri-implant bone repair of implants placed into the roots of delayed reimplanted teeth, in a process of ankylosis and external replacement resorption.Material and methodsThe third and fourth mandibular premolars of four (4) beagle dogs were used as experimental sites. The study was divided into three stages: stage 1 - endodontic and extraction/reimplantation session, stage 2 - decrowning session and stage 3 - implant placement. Two groups were identified: (I) immediate implants, including implants installed in fresh extraction sockets of the distal roots, and (II) experimental implants, including implants installed into the retained ankylotic mesial roots. In each group, 16 implants were planned to be inserted, but only 9 immediate implants and 12 experimental implants were used for analyses. Implants were intended to heal in a submerged mode. After 4 months of healing, the animals were sacrificed and ground sections were obtained for histomorphometric evaluation.ResultsEleven of the twelve implants in the experimental group were found successful regarding clinical and radiographic aspects. For immediate implants, a lower BIC% was found at the coronal portion (BIC% 1=42.2%) compared with the three most coronal threads portion (BIC% 2=55.1). Also, experimental implants presented a lower BIC% at the coronal portion (BIC% 1=36.9%) compared with the three most coronal threads portion (BIC% 2=45.3).ConclusionComparison between groups showed a higher degree of BIC% and mineralization in immediate group compared with experimental group. The differences, however, did not yield statistical significance.

Roots of the Invasive Species Carduus nutans L. and C-acanthoides L. Produce Large Amounts of Aplotaxene, a Possible Allelochemical

The invasive thistle Carduus nutans has been reported to be allelopathic, yet no allelochemicals have been identified from the species. In a search for allelochemicals from C. nutans and the closely related invasive species C. acanthoides, bioassay-guided fractionation of roots and leaves of each species were conducted. Only dichloromethane extracts of the roots of both species contained a phytotoxin (aplotaxene, (Z,Z,Z)-heptadeca-1,8,11,14-tetraene) with sufficient total activity to potentially act as an allelochemical. Aplotaxene made up 0.44 % of the weight of greenhouse-grown C. acanthoides roots (ca. 20 mM in the plant) and was not found in leaves of either species. It inhibited growth of lettuce 50%(I-50) in soil at a concentration of ca. 0.5 mg g(-1) of dry soil (ca. 6.5 mM in soil moisture). These values gave a total activity in soil value (molar concentration in the plant divided by the molarity required for 50 % growth inhibition in soil = 3.08) similar to those of some established allelochemicals. The aplotaxene I-50 for duckweed (Lemna paucicostata) in nutrient solution was less than 0.333 mM, and the compound caused cellular leakage of cucumber cotyledon discs in darkness and light at similar concentrations. Soil in which C. acanthoides had grown contained aplotaxene at a lower concentration than necessary for biological activity in our short-term soil bioassays, but these levels might have activity over longer periods of time and might be an underestimate of concentrations in undisturbed and/or rhizosphere soil.

Subacute and Reproductive Oral Toxicity Assessment of the Hydroethanolic Extract of Jacaranda decurrens Roots in Adult Male Rats

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Cell cultures of Maytenus ilicifolia Mart. are richer sources of quinone-methide triterpenoids than plant roots in natura

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Production of the Quinone-Methide Triterpene Maytenin by In Vitro Adventitious Roots of Peritassa campestris (Cambess.) ACSm. (Celastraceae) and Rapid Detection and Identification by APCI-IT-MS/MS

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Dynamics of soil exploration by fine roots down to a depth of 10 m throughout the entire rotation in Eucalyptus grandis plantations

Although highly weathered soils cover considerable areas in tropical regions, little is known about exploration by roots in deep soil layers. Intensively managed Eucalyptus plantations are simple forest ecosystems that can provide an insight into the belowground growth strategy of fast-growing tropical trees. Fast exploration of deep soil layers by eucalypt fine roots may contribute to achieving a gross primary production that is among the highest in the world for forests. Soil exploration by fine roots down to a depth of 10 m was studied throughout the complete cycle in Eucalyptus grandis plantations managed in short rotation. Intersects of fine roots, less than 1 mm in diameter, and medium-sized roots, 1-3 mm in diameter, were counted on trench walls in a chronosequence of 1-, 2-, 3.5-, and 6-year-old plantations on a sandy soil, as well as in an adjacent 6-year-old stand growing in a clayey soil. Two soil profiles were studied down to a depth of 10 m in each stand (down to 6 m at ages 1 and 2 years) and 4 soil profiles down to 1.5-3.0 m deep. The root intersects were counted on 224 m(2) of trench walls in 15 pits. Monitoring the soil water content showed that, after clear cutting, almost all the available water stored down to a depth of 7 m was taken up by tree roots within 1.1 year of planting. The soil space was explored intensively by fine roots down to a depth of 3 m from 1 year after planting, with an increase in anisotropy in the upper layers throughout the rotation. About 60% of fine root intersects were found at a depth of more than 1 m, irrespective of stand age. The root distribution was isotropic in deep soil layers and kriged maps showed fine root clumping. A considerable volume of soil was explored by fine roots in eucalypt plantations on deep tropical soils, which might prevent water and nutrient losses by deep drainage after canopy closure and contribute to maximizing resource uses.

Morphological effects of flooding on Styrax pohlii and the dynamics of physiological responses during flooding and post-flooding conditions

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Genotoxic effect of phenol on the cells of onion (Allium cepa ) roots

The roots of onion (Allium cepa ) stand out for having cells with large size and small number of chromosomes. These characteristics make them useful in bioassays for the measurement of a variety of cytogenetic and morphological parameters, in which they can be used as toxicity indicators of the induction and formation of micronuclei and chromosomal aberrations. Based on this background, the potential genotoxic effect of phenol concentration on cells of A. cepa roots was investigated either in terms of induced aberrations or micronuclei formation. The results demonstrated that the higher the concentration of phenol, the higher the incidence of abnormalities, thus confirming the genotoxicity of this pollutant.

Phytotoxicity of extracts and fractions of Ouratea spectabilis (Mart. ex Engl.) Engl. (Ochnaceae)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Differential gene expression in drought-tolerant sugarcane roots

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)