Departamento de Biologia

Brachycerine (1), an unusual alkaloid from the leaves of Psychotria brachyceras, was characterized through spectroscopic data interpretation and its stereochemistry established by NOE difference techniques. Brachycerine (1) was found to be restricted to shoots in rooted cuttings of P. brachyceras (0.018 ( 0.004% dry weight), and accumulation was unaffected by root induction treatment with auxin.

Psychollatine is an unusual indole alkaloid produced by Psychotria umbellata Vell, an Atlantic Forest understorey tree. Leaves, young inflorescences and fruit pulp displayed high amounts of psychollatine (from 2.5 to 4.5% dry wt). Seeds accumulated lower quantities (0.2% dry wt), and roots, trace amounts (0.06% dry wt). Alkaloid accumulation was not seasonally affected and leaf content was not significantly enhanced by wounding, exposure to salicylic acid, hydrogen peroxide, or UV. The alkaloid content in leaves decreased upon cutting exposure to auxin. Under strong UV, the amount of chlorophylls did not decrease compared to control contents at 48 and 72 h. Post-harvest psychollatine content in leaves was stable in different temperatures, except at 65 C. Psychollatine was an effective singlet oxygen, superoxide, and peroxide quencher. These antioxidant properties and the constitutively high amount of psychollatine indicate a role for the alkaloid in oxidative stress responses.

Some species of Psychotria (Rubiaceae) are important in herbal medicine, where their extracts are used internally for infections of the female reproductive system, bronchitis, gastrointestinal disturbances, skin irritations, tumors, ulcers, and eye disturbances. The antiproliferative and genotoxic effects of Psychotria myriantha Mull. Arg. and P. leiocarpa Cham. et Schlecht infusions on the Allium cepa L. cell cycle were evaluated. The teas were prepared by infusing the leaves in distilled water, in two concentrations: 1.13 mg/mL and 6.78 mg/mL. Three groups of four bulbs were used for each Psychotria species. After the bulbs rooted in distilled water, they were transferred to the teas for 24 hours, except for the control that stayed in water. The rootlets were then collected, fixed in ethanol-acetic acid (3:1) for 24 hours, and stored in 70% ethanol. For each group of bulbs, 4000 cells were analyzed, calculating the mitotic indexes, submitting them to statistic analysis, using the χ 2 test (p = 0.05). The results showed a decrease in mitotic index with an increase in tea concentration in both species. In P. leiocarpa, the mitotic index values differed significantly between the control and concentration of 6.78 mg/mL (χ 2 = 9.863). For P. myriantha, the values referring to the mitotic index differed greatly between the control and the treatments (χ 2 = 124.8). With this study, it was determined that P. myriantha and P. leiocarpa infusions possess antiproliferative effects on the A. cepa cell cycle, and teas of P. myriantha also have genotoxic activity.

Species of the genus Psychotria are used for multiple purposes in Brazilian folk medicine, either as water infusions, baths or poultices. This study was aimed to evaluate the genotoxic and antiproliferative effects of infusions of Psychotria brachypoda and P. birotula on the Allium cepa test. Exposure to distilled water was used as a negative control, while exposure to glyphosate was used as a positive control. The interaction of extracts (as a post-treatment) with the effects of glyphosate was also studied. Results showed that glyphosate and the extracts of both P. brachypoda and P. birotula reduced the mitotic index as compared with the negative control (distilled water). Surprisingly, however, both extracts from P. brachypoda and P. birotula caused a partial reversal of the antiproliferative effect of glyphosate when used as a post-treatment. Glyphosate also induced the highest number of cells with chromosomal alterations, which was followed by that of P. birotula extracts. Howev...

O objetivo deste trabalho foi comparar a riqueza, abundância e diversidade das espécies de Scarabaeidae em duas itoisionomias (campo e loresta) e veriicar se a variação sazonal ao longo do ano está relacionada com variáveis climáticas. O estudo foi desenvolvido na Reserva Biológica de São Donato, Rio Grande do Sul, Brasil (bioma Pampa). As coletas foram realizadas através de armadilhas de queda, entre janeiro de 2012 e janeiro de 2013. Foram coletados 125 indivíduos e identiicados seis gêneros e 11 espécies de quatro subfamílias, sendo 54 indivíduos de cinco espécies encontradas no campo e 71 indivíduos de oito espécies na loresta. As espécies mais abundantes foram Ataenius picinus Harold, 1868, Canthon lividus Blanchard, 1845 e Leucothyreus lavipes Eschscholtz, 1822, que representaram juntas 86,4% do total de indivíduos capturados. O verão apresentou o maior número de indivíduos (78) e a primavera o maior número de espécies (nove). A diferença na estrutura do ambiente (e clima associado) e provavelmente a disponibilidade diferenciada de recurso alimentar entre as duas itoisionomias devem ser fatores limitantes e decisivos para a ocorrência de cada subfamília em determinado habitat, uma vez que várias espécies foram restritas a determinada itoisionomia ou época do ano.

Ries ACR, Silva VC, da Silva PG, Blochtein B, Thyssen PJ. 2016. Record of Ataenius picinus Harold, 1868 (Coleoptera: Scarabaeidae: Aphodiinae) associated with exposed carcasses in Southern Brazil. Entomotropica 31(6): 48-53. Ataenius picinus Harold, 1868 is a scarab beetle, which is distributed worldwide. Individuals of this species have been found associated with animal feces, soil samples, leaf litter and decaying fruit, as some cases on carcasses. In this study, we propose the extension of trophic niche of this species based on observations of alternative scavenging resources. Individuals were collected from the carcasses of domestic pigs in southern Brazil. We collected 126 individuals, which represented 68 % of beetles collected during the total decomposition period (14 days). The observed abundance was higher in the decay stage and thus, given this preference, this species may be useful for estimating the maximum postmortem interval, based on the chronology of species arrival at the resource. Resumo Ries ACR, Silva VC, da Silva PG, Blochtein B, Thyssen PJ. 2016. Record of Ataenius picinus Harold, 1868 (Coleoptera: Scarabaeidae: Aphodiinae) associated with exposed carcasses in Southern Brazil. Entomotropica 31(6): 48-53. Ataenius picinus Harold, 1868 é um escarabeídeo com distribuição em todo mundo. Os indivíduos desta espécie têm sido encontrados associados com fezes de animais, amostras de solo, serapilheira e frutas em decomposição, e alguns casos em carcaças. Neste estudo, propomos a extensão do nicho trófico da espécie com base em observações de recursos de alimentação alternativos. Os indivíduos foram coletados a partir das carcaças de suínos domésticos no sul do Brasil. Foram coletados 126 indivíduos, o que representou 68 % dos besouros coletados durante o período de decomposição total (14 dias). A abundância observada foi maior na fase de murchamento, e dada essa preferência, a espécie pode ser útil para estimar intervalo post-mortem máximo, baseado na cronologia de chegada as espécies ao recurso. Palavras chave adicionais: Decomposição, entomologia forense, intervalo post-mortem.

Polynoncus vazdemelloi Huchet & Costa-Silva new species (Coleoptera: Trogidae) from Brazil is described and illustrated with data about the natural history and geographic distribution. Comparative data between P. vazdemelloi, P. juglans (Ratcliffe, 1978), and P. gemmingeri (Harold, 1872), species closely related morphologically, are given. Omorgus (Omorgus) triestinae Pittino, 1987 is removed from synonymy with O. (O.) suberosus (Fabricius, 1775) and reinstated as a valid species.

Rose: both Al-sensitive clones; and SMIC148-A and Solanum microdontum: both Al-tolerantclones), grown in a nutrient solution (pH 4.00) with 0, 50, 100, 150 and 200mg Al L -1 . Root Zn and Fe concentrations decreased linearly with the increase of Al levels in Macaca, SMIC148-A and Dakota Rose and increased linearly in S. microdontum. Shoot Zn concentration showed a quadratic relationship with Al in S. microdontum and SMIC148-A, but a curvilinear response in Dakota Rose. Shoot Fe concentration showed a quadratic relationship with Al in S. microdontum, SMIC148-A and Dakota Rose. Root Mn concentration decreased linearly in Macaca and SMIC148-A, and increased linearly in S. microdontum with Al levels. Mn concentration showed a quadratic relationship with Al in roots of Dakota Rose and in shoot of SMIC148-A, and increased curvilinearly with Al levels in shoot of Dakota Rose. In shoot, there was no alteration in Zn, Fe and Mn in Macaca and Mn concentration in S. microdontum. Roots and shoot Cu concentration increased linearly in Dakota Rose, and showed quadratic relationship with Al in Macaca. Roots Cu concentration showed a quadratic relationship with Al levels in S. microdontum and SMIC148-A. Shoot Cu concentration increased linearly in S. microdontum, and decreased linearly in SMIC148-A. Therefore, the excessive Al accumulation affected the uptake and distribution of Zn, Fe, Mn and Cu in roots and shoot of potato clones.The response of shoot Cu concentration to Al was less altered in the Al-tolerant clones than was in Al-sensitive clones. Aluminum tolerance in S. microdontum may be connected with greater levels of Zn, Fe and Mn in the roots. Tabaldi et al. Ciência Rural, v.39, n.2, mar-abr, 2009. nos clones Al-tolerantes que naqueles Al-sensíveis. A tolerância ao Al em S. microdontum pode estar conectada com os maiores níveis de Zn, Fe e Mn nas raízes. Palavras-chave: Solanum tuberosum, Solanum microdontum, zinco, manganês, ferro, cobre.

The objective of this study was to evaluate whether the oxidative stress caused by aluminum (Al) toxicity is an early symptom that can trigger root growth inhibition in Macaca (Al-sensitive) and SMIC148-A (Al-tolerant) potato clones. Plantlets were grown in a nutrient solution (pH 4.00) with 0, 100 and 200 mg Al L À1 . At 24, 72, 120 and 168 h after Al addition, root length and biochemical parameters were determined. Regardless of exposure time, root length of the Macaca clone was significantly lower at 200 mg Al L À1 . For the SMIC148-A clone, root length did not decrease with any Al treatments. Al supply caused lipid peroxidation only in Macaca, in both roots (at 24, 72, 120 and 168 h) and shoot (at 120 and 168 h). In roots of the Macaca, catalase (CAT) and ascorbate peroxidase (APX) activity decreased at 72 and 120 h, and at 24, 72 and 120 h, respectively. At 168 h, both activities increased upon addition of Al. In roots of the SMIC148-A, CAT activity increased at 72 and 168 h, whereas APX activity decreased at 72 h and increased at 24, 12 and 168 h. The Macaca showed lower root non-protein thiol group (NPSH) concentration at 200 mg Al L À1 in all evaluations, but the SMIC148-A either did not demonstrate any alterations at 24 and 72 h or presented higher levels at 120 h. This pattern was also observed in root ascorbic acid (AsA) concentration at 24 and 120 h. The cellular redox status of these potato clones seems to be affected by Al. Therefore, oxidative stress may be an important mechanism for Al toxicity, mainly in the Al-sensitive Macaca clone.

In order to evaluate the effect of cadmium (Cd 2þ ) toxicity on mineral nutrient accumulation in potato (Solanum tuberosum L.), two cultivars named Asterix and Macaca were cultivated both in vitro and in hydroponic experiments under increasing levels of Cd 2þ (0, 100, 200, 300, 400 and 500 mM in vitro and 0, 50, 100, 150 and 200 mM in hydroponic culture). At 22 and 7 days of exposure to Cd 2þ , for the in vitro and hydroponic experiment, respectively, the plantlets were separated into roots and shoot, which were analyzed for biomass as well as Cd 2þ , and macro (Ca 2þ , K þ and Mg 2þ ) and micronutrient (Cu 2þ , Fe 2þ , Mn 2þ and Zn 2þ ) contents. In the hydroponic experiment, there was no reduction in shoot and root dry weight for any Cd 2þ level, regardless of the potato cultivar. In contrast, in the in vitro experiment, there was an increase in biomass at low Cd 2þ levels, while higher Cd 2þ levels caused a decrease. In general, Cd 2þ decreased the macronutrient and micronutrient contents in the in vitro cultured plantlets in both roots and shoot of cultivars. In contrast, the macronutrient and micronutrient contents in the hydroponically grown plantlets were generally not affected by Cd 2þ . Our data suggest that the influence of Cd 2þ on nutrient content in potato was related to the level of Cd 2þ in the substrate, potato cultivar, plant organ, essential element, growth medium and exposure time.

In vitro growth of potato plantlets in different doses of cadmium -NOTA -RESUMO Devido, principalmente, às ações antropogênicas, tais como industrialização e uso de insumos na agricultura, os níveis de cádmio têm aumentado em muitos solos agrícolas. O presente trabalho objetivou caracterizar o efeito desse metal no crescimento in vitro de duas cultivares de batata, 'Asterix' e 'Macaca'. Segmentos nodais de plantas previamente estabelecidas in vitro foram submetidos a doses de cádmio de 0 (controle), 100, 200, 300, 400 e 500μM em meio de cultivo MS. Avaliou-se o número de raízes aos 15 dias após a inoculação (DAI) dos explantes, o comprimento das raízes e da parte aérea, o número de segmentos nodais e de folhas e a matéria fresca e seca das raízes e da parte aérea aos 22DAI. O cádmio afetou negativamente o crescimento das duas cultivares de batata, demonstrando que ambas são sensíveis a esse metal. Palavras-chave: Solanum tuberosum, metal pesado, clones, toxicidade. ABSTRACT Levels of cadmium have been increasing in many agricultural soils mainly due to the anthropogenic actions, such as industrialization and use of inputs in the agriculture. The present research aimed at characterizing the effect of this metal on in vitro growth of two potato cultivars, 'Asterix' and 'Macaca'. Nodal segments of plants previously in vitro established were submitted to cadmium concentration of 0 (control), 100, 200, 300, 400 and 500μM in MS. Number of roots was evaluated at 15 days after inoculation (DAI) of the explants, and root and shoot length, number of nodal segments and leaves, and fresh and dry mass of roots and shoot were evaluated at 22DAI. Cadmium negatively affected the growth of the two potato cultivars, demonstrating that both are sensible to this metal.