scholarly journals Environmental Risk Characterization of an Antiretroviral (ARV) Lamivudine in Ecosystems

2021 ◽  
Vol 18 (16) ◽  
pp. 8358
Author(s):  
Elizabeth Oyinkansola Omotola ◽  
Bettina Genthe ◽  
Luyanda Ndlela ◽  
Olatunde Stephen Olatunji
Keyword(s):  
Daphnia Magna ◽  
Allium Cepa ◽  
Lactuca Sativa ◽  
Germination Rate ◽  
Survival Rates ◽  
Antiretroviral Drugs ◽  
Trophic Levels ◽  
Adverse Impact ◽  
Root Tip ◽  
Root Tips

Antiretroviral drugs for the treatment of human immunodeficiency virus (HIV) and other viral infections are among the emerging contaminants considered for ecological risk assessment. These compounds have been reported to be widely distributed in water bodies and other aquatic environments, while data concerning the risk they may pose to unintended non-target species in a different ecosystem (environment) is scanty. In South Africa and other developing countries, lamivudine is one of the common antiretrovirals applied. Despite this, little is known about its environmental impacts as an emerging contaminant. The present study employed a battery of ecotoxicity bioassays to assess the environmental threat lamivudine poses to aquatic fauna and flora. Daphnia magna (filter feeders), the Ames bacterial mutagenicity test, Lactuca sativa (lettuce) germination test, and the Allium cepa root tip assay were conducted, testing lamivudine at two concentrations (10 and 100 µg/L), with environmental relevance. The Daphnia magna toxicity test revealed a statistically significant response (p << 0.05) with a mortality rate of 85% on exposure to 100 µg/L lamivudine in freshwater, which increased to 100% at 48-h exposure. At lower concentrations of 10 µg/L lamivudine, 90% and 55% survival rates were observed at 24 h and 48 h, respectively. No potential mutagenic effects were observed from the Ames test at both concentrations of lamivudine. Allium cepa bioassays revealed a noticeable adverse impact on the root lengths on exposure to 100 µg/L lamivudine. This impact was further investigated through microscopic examination, revealing some chromosomal aberration in the exposed Allium cepa root tips. The Lactuca sativa bioassay showed a slight adverse impact on both the germination rate of the seeds and their respective hypocotyl lengths compared to the control. Overall, this indicates that lamivudine poses an ecological health risk at different trophic levels, to both flora and fauna, at concentrations previously found in the environment.

scholarly journals Índices de calidad ambiental de aguas del Arroyo Caañabe mediante tests microbiológicos y ecotoxicológico

2016 ◽  
Vol 11 (3) ◽  
pp. 548
Author(s):  
Tomás Rodrigo López Arias ◽  
Virginia Florencia Fernández Peralta ◽  
Deidamia Mercedes Franco de Diana ◽  
Edgar Fidel Galeano Delgado ◽  
Fernando Salvador Alonso Márquez ◽  
...  
Keyword(s):  
Daphnia Magna ◽  
Allium Cepa ◽  
Danio Rerio ◽  
Lactuca Sativa ◽  
E Coli ◽  
Los Grupos

El Arroyo Caañabe, es un curso de agua que corre a través de los Departamentos Central y Paraguarí (República del Paraguay). Las descargas de origen agropecuario, urbano e industrial contaminan sus aguas. En este trabajo se evalúa la calidad del arroyo mediante sus características fisicoquímicas, ecotoxicológicas, microbiológicas y se la comparan con la legislación vigente. Se colectaron muestras en los meses de Julio y Setiembre del año 2014. Se estudiaron tres sitios denominados S1, ubicado en aguas arriba de la Ciudad de Carapegua; S2 en la intersección del arroyo con la Ruta 1, y S3, en la zona límite de las ciudades de Carapegua y Nueva Italia. Se realizaron ensayos de toxicidad aguda con Daphnia magna, Lactuca sativa, y alevines de Danio rerio; además de ensayos crónicos en Tetradesmus wisconsinenesis, D. rerio y Allium cepa. Se evaluaron los grupos y especies microbianos siguientes: aerobios mesófilos, enterobacterias, coliformes totales, coliformes fecales, E. coli, Pseudomona aeruginosa, mohos y levaduras; además se determinaron índices de calidad y de contaminación. Los resultados indican que las aguas del arroyo presentaron características de clase II y de clase III según el padrón establecido por la Secretaría del Ambiente del Paraguay. El índice de calidad de agua (ICA) arrojó valores comprendidos entre 52 y 62 lo que otorga la clasificación de “regular”; mientras que el índice de contaminación trófica (ICOTRO) presentó valores entre 0,12 y 0.26, indicando “eutrofización”. Los recuentos de coliformes fueron superiores en el segundo muestreo, aunque dentro lo establecido por la norma. La presencia de P. aeruginosa en los tres puntos constituye un riesgo para la salud. Ensayos ecotoxicológicos agudos mostraron que las aguas presentan escasos efectos letales, no obstante los ensayos crónicos en A. cepa y el test de micronúcleos en D. rerio indican potenciales efectos citotóxicos y genotóxicos de las aguas del Arroyo Caañabe.

scholarly journals Genotoxic Effect of Heavy Metals Cr, Cu, Pb and Zn using Allium cepa L.

2017 ◽  
Vol 14 (3) ◽  
pp. 1181-1186 ◽  
Author(s):  
M.N. Abubacker ◽  
C. Sathya
Keyword(s):  
Heavy Metals ◽  
Allium Cepa ◽  
Chromosomal Abnormalities ◽  
Root Tip ◽  
Chromosome Loss ◽  
Chromosome Break ◽  
Root Tips ◽  
Lead And Zinc ◽  
Chromosome Bridge ◽  
Copper Lead

ABSTRACT: Angiosperms are recognized as appropriate genetic models to detect heavy metal based environmental mutagens and are used in monitoring studies. Allium cepa (onion) has been used to evaluate DNA damages like chromosome aberrations and abnormalities in the mitotic cycle. The aim of the present study is to analyze the cytotoxic effects of chromium, copper, lead and zinc in A. cepa root tip squash mitotic cell divisions. The root tips were treated with three concentrations, viz. 5, 10 and 20 mg/100 ml of chromium, copper, lead and zinc at room temperature for 24 h. Mitotic indices and chromosomal abnormalities were calculated. It was observed that these heavy metals induced different types of chromosomal abnormalities comprising of Chromosome break, Chromosome bridge, C-mitosis, Vagrant, Delayed Anaphase and Vagrant, Chromosome Loss, Polyploidy and Chromosome Bridge, Chromosome Loss and Loculated Nucles, Stickiness, Multipolarity and Polyploid prophase along with the increasing doses. The effect of chromium and lead at 20 mg/100 ml concentration was found to be more toxic rather than copper and zinc to the root meristem of A. cepa. The ranking of cytotoxic potentials was in the descending order: lead > chromium > copper > zinc.

scholarly journals Effect of Ferrous Gluconate on Chromosomal Abnormality Index of Allium Cepa Root Tip

2021 ◽  
Vol 9 (4) ◽  
pp. 755-758
Author(s):  
Nergis Kaya
Keyword(s):  
Allium Cepa ◽  
Chromosomal Aberration ◽  
Chromosomal Abnormality ◽  
Genotoxic Effect ◽  
Root Tip ◽  
Control Group ◽  
Root Tips ◽  
Ferrous Gluconate ◽  
Allium Cepa L ◽  
Abnormality Index

In completed research, ferrous gluconate -a food additive- used to preserve black color to prevent discoloration during storage in ripe black olives, and Allium cepa L. species. A. cepa L. roots were treated with different doses of ferrous gluconate. The effective concentration EC50 (0.068 g/l) was determined. A. cepa root tips were treated with EC50/2 (0.034 g/l), EC50 (0.068 g/l), 2XEC50 (0.136 g/l) dose for 24, 48, 72 hours, and afterward, the root tips were prepared for observation under the light microscope according to the method of preparing mitotic preparation. Chromosomal abnormality index (CAI) and genotoxic effect of ferrous gluconate in A. cepa root tip cells were determined. Repeated measurement ANOVA and TUKEY multiple comparison tests were used to investigate the effect of time and dose together on genotoxicity. C-mitosis, polyploidy, polar shifting in anaphase, polar shifting in telophase, equatorial plate shifting, laggard chromosome was observed by microscope. The highest CAI (70.16±4.85) was observed at 72h for 2XEC50 dose. Chromosomal aberration is also observed in control group. While the most common chromosomal aberration is determined as C-mitosis; The least observed chromosomal aberration is determined as polyploidy. Research results revealed that ferrous gluconate has a genotoxic effect on the root tip of A. cepa.

DIURNAL RHYTHMS IN MITOSIS OF CELLS OF THE ONION ROOT TIP MERISTEM

1971 ◽  
Vol 13 (3) ◽  
pp. 597-599 ◽  
Author(s):  
Richard C. Bishop ◽  
Richard M. Klein
Keyword(s):  
Mitotic Activity ◽  
Allium Cepa ◽  
Constant Temperature ◽  
Time Of Day ◽  
Diurnal Rhythms ◽  
Root Tip ◽  
Root Tips ◽  
Complete Darkness ◽  
Onion Root

Seeds of Allium cepa were grown in complete darkness at constant temperature. The root tips, collected from hours 72 to 96 after the start of imbibition, exhibited four maxima and four minima in mitotic activity. The timing of this rhythm was dependent upon the time of imbibition and not upon the time of day.

scholarly journals Systemic Control of Cell Division and Endoreduplication by NAA and BAP by Modulating CDKs in Root Tip Cells ofAllium cepa

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Jigna G. Tank ◽  
Vrinda S. Thaker
Keyword(s):  
Cell Division ◽  
Allium Cepa ◽  
Vegetative Growth ◽  
Research Work ◽  
Colchicine Treatment ◽  
Root Tip ◽  
Root Tips ◽  
Ofallium Cepa ◽  
Elongation Process ◽  
Growth Formation

Molecular mechanism regulated by auxin and cytokinin during endoreduplication, cell division, and elongation process is studied by usingAllium cepa rootsas a model system. The activity of CDK genes modulated by auxin and cytokinin during cell division, elongation, and endoreduplication process is explained in this research work. To study the significance of auxin and cytokinin in the management of cell division and endoreduplication process in plant meristematic cells at molecular level endoreduplication was developed in root tips ofAllium cepaby giving colchicine treatment. There were inhibition of vegetative growth, formation of c-tumor at root tip, and development of endoreduplicated cells after colchicine treatment. This c-tumor was further treated with NAA and BAP to reinitiate vegetative growth in roots. BAP gave positive response in reinitiation of vegetative growth of roots from center of c-tumor. However, NAA gave negative response in reinitiation of vegetative growth of roots from c-tumor. Further, CDKs gene expression analysis from normal, endoreduplicated, and phytohormone (NAA or BAP) treated root tip was done and remarkable changes in transcription level of CDK genes in normal, endoreduplicated, and phytohormones treated cells were observed.

scholarly journals Phytotoxic Activity of p-Cresol, 2-Phenylethanol and 3-Phenyl-1-Propanol, Phenolic Compounds Present in Cistus ladanifer L.

Plants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1136
Author(s):  
Cristina Tena ◽  
Ana del Rosario Santiago ◽  
Dolores Osuna ◽  
Teresa Sosa
Keyword(s):  
Allium Cepa ◽  
Lactuca Sativa ◽  
Germination Rate ◽  
Cistus Ladanifer ◽  
Phytotoxic Activity ◽  
Phenolic Components ◽  
Leaf Exudate ◽  
Very High ◽  
Mediterranean Shrub ◽  
High Diversity

Numerous studies about the leaf exudate of Cistus ladanifer highlight this Mediterranean shrub as an allelopathic species. Despite the very high diversity of secondary metabolites identified in its labdanum, only a few components have been evaluated. p-Cresol, 2-phenylethanol and 3-phenyl-1-propanol are three phenolic components present in the labdanum of C. ladanifer whose role has not been specified to date. The present study, through a static acute toxicity test, analyzed their activity, with respect to Allium cepa and Lactuca sativa. These three separate compounds and the mixture of all of them have a more or less phytotoxic activity depending on the medium, species and concentration tested. When the test is carried out on paper, the three pure allelochemicals and their mixture at 1 mM significantly inhibited the total germination, the germination rate and the development of the Allium cepa and Lactuca sativa seedlings to a lesser extent, but when the test performed in soil, the effects on the size of roots and cotyledons are attenuated. Furthermore, in the two species tested on paper, the joint action of the three compounds at 1 mM shows a significantly greater inhibition of the measured indices than each of the compounds separately.

Root Tip Growth and the Presence of Leaves Affect Epicormic and Lignotuberous Shoot Development and Survival of Stressed Eucalyptus obliqua L’Herit. Seedlings

2021 ◽  
Vol 47 (4) ◽  
pp. 133-149
Author(s):  
G.M. Moore
Keyword(s):  
Shoot Growth ◽  
Tip Growth ◽  
Survival Rates ◽  
Root Tip ◽  
Soil Conditions ◽  
Plant Responses ◽  
Root Tips ◽  
Shoot Production ◽  
The Relationship ◽  
Different Levels

The shoots produced from axillary, epicormic, and lignotuberous buds are significant parts of stress recovery responses in many tree species. The production of either epicormic or lignotuberous shoots does not guarantee survival of a tree, as the mortality of shoots is high. This research investigated the relationship between root tip growth and shoot production and survival after stress and its implications for urban tree managers. Seedlings of Eucalyptus obliqua L’Herit. were stressed by decapitation or different levels of heat stress at temperatures ranging from 40 °C to 100 °C for 2 to 128 minutes, as well as combinations of the two stresses. While the temperatures are not as high as those experienced in a forest fire, the stresses imposed can inform plant responses to stress such as fire. Lower temperatures and shorter durations were often sublethal, and decapitation, to the same extent as heat killing of plant tissues, elicited similar levels of epicormic and lignotuberous shoot growth. The root systems of the seedlings were inspected to determine whether the root tips were healthy, and selected root tips were monitored to determine if and when they had resumed growth. Survival rates of epicormic and lignotuberous shoots were enhanced by the presence of healthy leaves. The recommencement of growth after stress by the development of epicormic or lignotuberous shoots was preceded by root tip growth, which emphasises the importance of a healthy root system. Managing for the best soil conditions possible during and immediately after stress may be a key to successful shoot production and tree recovery.

scholarly journals Utilización de bioensayos para la determinación de contaminación en agua de riego en la cuenca del río Granobles

La Granja ◽  
2006 ◽  
Vol 4 (1) ◽  
pp. 38
Author(s):  
Rocío Contero ◽  
Orlando Felicita
Keyword(s):  
Daphnia Magna ◽  
Allium Cepa ◽  
Lactuca Sativa ◽  
Pistia Stratiotes ◽  
Del Rio ◽  
Oriza Sativa

El uso de los bioensayos como indicadores del grado de afectación de una sustancia química en organismos vivos, ha sido manejado bajo condiciones controladas de laboratorio desde hace mucho tiempo; se ha trabajado con éxito en varios países latinoamericanos (Colombia, Chile, Argentina, Cuba y otros), especialmente utilizando cebolla de bulbo (Allium cepa), lechuga (Lactuca sativa), pulga de agua (Daphnia magna), algas (Hidra attenuata), arroz (Oriza sativa), repollito de agua (Pistia stratiotes), larva y adultos de Aedes aegypty, entre las principales.

Histochemical Examination of Invertase Activities in the Growing Tip of the Plant Root

2017 ◽  
Vol 10 (1) ◽  
pp. 35-45
Author(s):  
N.F. Lunkova ◽  
N.A. Burmistrova ◽  
M.S. Krasavina
Keyword(s):  
Plant Root ◽  
Invertase Activity ◽  
Root Tip ◽  
Elongation Zone ◽  
Root Tips ◽  
Phloem Unloading ◽  
Meristem Cell ◽  
Transition To Elongation ◽  
Different Tissues

Background:A growing part of the root is one of the most active sinks for sucrose coming from source leaves through the phloem. In the root, sucrose is unloaded from conducting bundles and is distributed among the surrounding cells. To be involved in the metabolism, sucrose should disintegrate into hexoses by means of degrading enzymes.Aims:The aim of this research was to explore the possibility of the involvement of one such enzymes, invertase, in phloem unloading as well as distribution of its activity in the functionally different tissues of the plant root tips.Method:To estimate the enzyme activities in root tissues, we applied two techniques: the histochemical method using nitro blue tetrazolium. The localization of phloem unloading was studied with carboxyfluorescein, a fluorescent marker for symplastic transport.Results:Invertase activity was not detected in the apical part of the meristem. It appeared only between the basal part of this zone and the beginning of the elongation zone. There is the root phloem unloading in that area. Invertase activity increased with increasing the distance from the root tip and reached the highest values in the region of cell transition to elongation and in the elongation zone. The activities of the enzyme varied in different tissues of the same zone and sometimes in the neighboring cells of the same tissue. Biochemical determination of invertase activity was made in the maize root segments coincident to the zones of meristem, cell elongation and differentiation. The results of both methods of determination of invertase activity were in agreement.Conclusion:It was concluded that phloem unloading correlated with invertase activity, possibly because of the activation of invertase by unloaded sucrose. Invertase is one of the factors involved in the processes preparing the cells for their transition to elongation because the concentration of osmotically active hexoses increases after cleavage of sucrose, that stimulates water entry into the cells, which is necessary for elongation growth.

Sign in / Sign up

Export Citation Format

Share Document