Toxicity of the emerging pollutants propylparaben and dichloropropylparaben to terrestrial plants.

Propylparaben (PrP) and dichloropropylparaben (diClPrP) are found in soil worldwide, mainly due to the incorporation of urban sludge in crop soils and the use of non-raw wastewater for irrigation. Studies on the adverse effects of PrP on plants are incipient and not found for diClPrP. PrP and diClPrP were evaluated at concentrations 4, 40, and 400 µg/L for their phytotoxic potential to seeds of Allium cepa (onion), Cucumis sativus (cucumber), Lycopersicum sculentum (tomato), and Lactuca sativa (lettuce), and cytotoxic, genotoxic potential, and for generating oxygen-reactive substances in root meristems of A. cepa bulbs. PrP and diClPrP caused a significant reduction in seed root elongation in all four species. In A. cepa bulb roots, PrP and diClPrP resulted in a high prophase index; in addition, PrP at 400 µg/L and diClPrP at the three concentrations significantly decreased cell proliferation and caused alterations in a significant number of cells. Furthermore, diClPrP concentrations induced the development of hooked roots in onion bulbs. The two chemical compounds caused significant changes in the modulation of catalase, ascorbate peroxidase, and guaiacol peroxidase, disarming the root meristems against hydroxyl radicals and superoxides. Therefore, PrP and diClPrP were phytotoxic and cytogenotoxic to the species tested, proving dangerous to plants.

A study on phytogenotoxicity induced by biogenic amines: cadaverine and putrescine.

Among the compounds present in necro-leachate, a liquid released during the process of decomposition of the human body, are the biogenic amines cadaverine and putrescine. Although some studies on necro-leachate have indicated a potential ecotoxicological and public health risk associated with it, the research on this type of contamination is still rather limited. This study presents information about the phytotoxic and cytogenotoxic potential of cadaverine and putrescine, evaluated separately and within a mixture. Phytotoxicity was evaluated through a germination test, the initial growth of seedlings with Lactuca sativa, and cytogenotoxicity through chromosomal aberration and micronucleus tests with Allium cepa. The L. sativa results showed a phytotoxic effect for the evaluated amines, by reducing root (> 90%) and hypocotyl (> 80%) elongation. The co-exposure of cadaverine and putrescine potentiated cytogenotoxic activity by aneugenic action in the meristematic cells of A. cepa. From this result, it is possible to infer the eco-toxicogenic potential of cadaverine and putrescine. This study not only highlights the importance of the phytotoxic and cytogenotoxic effects of these amines but also emphasizes the urgent need for further investigation into contamination originating from cemetery environments. By evaluating the risks associated with necro-leachate, this research is aimed at informing global efforts to protect ecological and public health.

Diaspore dispersal season influences root growth and seed traits, but not germination responses, of sympatric Piper species in a seasonal forest.

Seeds may differ in terms of dormancy, longevity, sensitivity to desiccation and dry mass, according to the timing (dry season/rainy season) of diaspore dispersal. In addition, seasonal variations in temperature and water availability can act as signals of the season during seed development, influencing germination responses and root growth. We evaluated the effects of temperature variations and water availability on germination parameters, root growth and seed traits of four coexisting Piper species in seasonal vegetation that differed in diaspore dispersal timing. Eight temperature treatments (15, 20, 23, 25, 28, 30, 35 °C, and alternate 30 °C-20 °C) and four induced water potentials (0, -0.3, -0.6 and -1.2 MPa) were used. The parameters germination onset, germination percentage (G%), mean germination time (MGT), root elongation, seed longevity during ex situ storage and dry mass of seeds were evaluated. Germination responses observed were independent of the diaspore dispersal timing, such as variations in germination onset, G% and MGT, both in temperature and water availability treatments. In contrast, root elongation, longevity and dry mass of seeds varied according to the time of diaspore dispersal. Our results corroborate the hypothesis that the timing of diaspore dispersal is an important factor in controlling the initial development of seedlings in seasonal vegetation, but not in germination responses. The predominance of negative effects of temperature increases and water deficit on root growth shows that the initial stages of plant development can be strongly impacted by these environmental factors.

Phytotoxicity indexes and removal of color, COD, phenols and ISA from pulp and paper mill wastewater post-treated by UV/H2O2 and photo-Fenton.

Pulp and paper mill wastewater (PPMWW) contains high concentrations of recalcitrant compounds that cause toxicity to organisms. Advanced oxidation processes (AOPs) have the ability to degrade these compounds and reduce overall toxicity. Physicochemical characterization and Lactuca sativa toxicity test were conducted to compare the effectiveness of two post-treatments: UV/H2O2 and photo-Fenton. A comparison of four phytotoxicity indexes was carried out. PPMWW from a Brazilian treatment plant was characterized by high values of phenols, color, integrated spectral area (ISA), and chemical oxygen demand (COD), and caused significant inhibition to seedling development. The use of both post-treatments allowed the removal of over 75% of phenols, color, ISA, and COD. Although UV/H2O2 was more effective in removing phenols and ISA, photo-Fenton better reduced phytotoxicity. The most sensitive phytotoxicity indexes were RGIC0.8 and GIC80%, whereas SGC0, REC-0.25 and REC-0.50 better showed the effectiveness of the post-treatments. We suggest the combined use of two phytotoxicity indexes: one that evaluates the effects on seed germination and, another, on root elongation, e.g., SGC0 and RGIC0.8. Additionally, we recommend the use of ISA for monitoring programs of wastewater treatments because it is a cost-effective approach that allows narrowing down the search and identification of compounds present in complex mixtures.

Milli-channel array for direct and quick reading of root elongation bioassays.

A novel platform to perform systematic analysis and direct reading of root elongation bioassays is presented. The device was designed to include multiplexed microenvironments for the germination and growth of individual seeds, which allows observation by the naked eye or by optical systems, notably cellphone cameras. Prototypes were fabricated by laser micromachining on a highly transparent material that is fully compatible with biological systems. The effectiveness of the milli-channel array was verified against the conventional system (Petri dish). Lactuca sativa was chosen as a model species and glyphosate as a typical toxic agent. All tests were run according to standardized procedures and data analysis was carried out through different statistical indicators such as the root elongation and germination indexes. Results attained in the milli-channel array were identical to those in Petri dish, with the remarkable benefit that several steps required in the conventional system were avoided, which enormously decreases the operation time and the possibility of experimental errors. Further advantages of the milli-channel array are also reported, such as the capability to achieve live imaging of plant organs growth through a simple experiment. The developed device has been proven to be effective, versatile, easy-to-use, and integrable to cellphones, which naturally provide facilities for data recording, analysis, and networking. These improvements open the route to novel applications of bioassays in the wide field of ecotoxicology and environmental studies.

Allelopathic activity of micropropagated Hyssopus officinalis L., Lamiaceae, water infusions / Atividade alelopática de micropropagado Hyssopus officinalis L. infusãos aquosos

The natural habitats of Hyssopus officinalis L. (Lamiaceae) in Bulgaria are not sufficient to satisfy the needs of this herb. Micropropagation might be used for obtaining plants with desirable traits. Hyssopus is a medicinal aromatic plant that has not been studied very much. Recently aromatic plants were investigated as potent allelopathic plants. Determining the modes of action of allelochemicals is one of the challenging aspects in allelopathic studies. The objective of this study was to determine the allelopathic activity of micropropagated Hyssopus officinalis L. water infusions. We evaluated the influence of hot and cold infusions made from the aerial parts of hyssopus under laboratory conditions. For this purpose we tested the effects of infusions on germination and root elongation of Cucumis sativus L. and Triticum aestivum L. We determined also the effect on mitotic activity using Allium cepa L. chromosome aberration test. The results demonstrated the presence of water soluble allelopathic compounds in hyssopus tissue. Infusions exhibited growth depressive effect which was stronger at early stage of growth. The inhibitory effects on germination and root elongation were stronger in T. aestivum than in C. sativus. Hyssopus also exerted mitodepressive and genotoxic effect in Allium cepa root tip cells.

Os hábitats naturais de Hyssopus officinalis L. (Lamiaceae) na Bulgária não são suficientes para satisfazer as necessidades desta erva. A micropropagação poderia ser usada para obter plantas com características desejáveis. Hyssopus é uma planta aromática medicinal que não foi estudada muito. Recentemente plantas aromáticas foram investigadas como potentes plantas alelopáticas. A determinação dos modos da ação de aleloquímicos é um dos aspectos desafiantes em estudos alelopáticos. O objetivo deste estudo foi determinar a atividade alelopática de micropropagado Hyssopus officinalis L. infusãos aquosos. Foi avaliada a influência de infusões quentes e frias feito de partes aéreas de hyssopus sob condições de laboratório. Com este propósito nós testou os efeitos de infusões em germinação e alongamento de raiz de Cucumis sativus L. e Triticum aestivum L. Determinamos também o efeito na atividade mitótica usando os Allium cepa L. teste de aberração cromossômica. Os resultados demonstraram a presença de compostos alelopáticos solúveis de água em tecido de hyssopus. As infusões exibiram o efeito depressivo do crescimento que era mais forte na fase inicial de crescimento. Os efeitos inibitivos em germinação e alongamento de raiz foram mais fortes em T. aestivum que em C. sativus. Hyssopus também exerceu efeito genotóxico e mitodepressivo em células de ponta de raiz de Allium cepa.

Toxicidade do lodo gerado pelo tratamento biológico da água de produção, no terminal marítimo almirante barroso, município de são sebastião, sp

ABSTRACT One of oil production characteristics is the mixed water volume co-produced. This water contain must be eliminated before refinery processing, originating a wastewater known as Produced Water. These waste treatment systems are designed by a combination of different methodologies, looking for greater treatment efficiency. In the mean time, treatment processes generate byproducts that need an ultimate disposal. This paper objective is to evaluate the solubilization product toxicity, from a biological sludge, produced at a Pilot Produced Water Treatment Facility, located on Terminal Marítimo Almirante Barroso. The species: Barabarea verna Mill., Brassica. oleraceaL., Cucumis. sativus L. and Eruca. sativa Mill., were used for bioassays tests based on germination percentage, germination velocity and root/hypocotyls elongation. Results indicate B. verna greater solubilization product germination sensibility, the remaining species showed a critical concentration of solubilization product about 25%. The root/hypocotyls elongation tests indicate E. sativa and B. oleracea greater resistance, with root inibitory concentration (IC 50) of 23.61% and 16.64% respectively and, IC50 for hypocotyls about 18% for both species.

RESUMO A exploração dos campos produtores de petróleo tem como característica a extração de uma parcela de água misturada ao óleo. Esta água deve ser separada do petróleo antes do processamento pelas refinarias, assim, originando um resíduo conhecido como Água de Produção (AP). Os sistemas projetados para o tratamento da AP empregam diferentes métodos, visando atingir maior eficiência na separação dos contaminantes da água. Entretanto, os processos de tratamento geram subprodutos que necessitam de posterior manuseio ou descarte. O presente trabalho tem como objetivo avaliar a toxicidade do produto de solubilização do lodo gerado pelo tratamento da AP em reatores aeróbios, proveniente da estação piloto de tratamento do efluente do Terminal Marítimo Almirante Barroso. Foram testadas as espécies: Barabarea verna Mill ., Brassica oleracea L., Cucumis sativus L. e Eruca sativa Mill., quanto à porcentagem de germinação, velocidade média de germinação e inibição ao crescimento da raiz e hipocótilo. Os resultados indicam maior sensibilidade da germinação de B. verna ao extrato solubilizado, as demais espécies apresentaram concentração crítica para a germinação entorno de 25% do extrato solubilizado. A inibição ao crescimento da raiz e hipocótilo indica maior resistência das espécies E. sativa e B. oleracea, a concetração de inibição (CI50) para essas espécies foi respectivamente de 23,61% e 16,64% para a raiz, para o hipocótilo a CI50 foi em torno de 18% para as duas espécies.

Behaviour of enzymatic activities and root elongation in Argiudoll soils from the Argentine Humid Pampa treated with biosolids / Comportamiento de actividades enzimáticas y elongación de raíces en suelos Argiudoles de la Pampa Húmeda, Argentina, tratados con biosólidos

The incorporation of biosolids to soil is a strategy aiming at the re-location of these materials in the environment with a useful end: soil fertilization. In this work, the response of two Argiudoll soils (one with more than 100 years of agriculture and the other, a virgin one) to biosolid incorporation was studied under laboratory conditions. To measure this response, soil enzymatic biodescriptors, such as dehydrogenase and urease activities, and tests related to plant physiology (the root elongation test) were employed. The addition of the biosolid to both soils had a stimulating effect though different on each soil according to the added dose. Adjustment of the regression line for dehydrogenase activity with root elongation was positive and statistically significant (p<0.001). Results suggest that biodescriptors employed were suitable for studying the impact of amended biosolids on different soils.

La incorporación de biosólidos al suelo es una estrategia que tiene como objetivo la reubicación de estos materiales en el ambiente con un fin útil, como es la fertilización del suelo. En este trabajo se estudió, en condiciones controladas de laboratorio, la respuesta de dos suelos Argiudoles (uno con más de 100 años de agricultura y otro virgen) frente a la perturbación físico-química y biótica que genera la incorporación de un biosólido. Para medir esta respuesta se emplearon dos biodescriptores edáficos (las actividades deshidrogenasa y ureasa) y un tercero referido a la fisiología vegetal, la prueba de elongación de raíces. La incorporación del biosólido en ambos suelos, en general no deprimió el funcionamiento de las actividades enzimáticas estudiadas; contrariamente, según la dosis aportada tuvo un efecto estimulante, aunque diferente, entre ambos suelos. El ajuste de la recta de regresión de la actividad deshidrogenasa con la elongación de las plántulas fue positivo y altamente significativo, lo que indica la complementaridad de ambos descriptores. Los resultados obtenidos sugieren que los biodescriptores empleados resultaron aptos para estudiar el impacto que produce la incorporación de biosólidos a suelos agrícolas.