Neighbour-induced changes in root exudation patterns of buckwheat results in altered root architecture of redroot pigweed.

Roots are crucial in plant adaptation through the exudation of various compounds which are influenced and modified by environmental factors. Buckwheat root exudate and root system response to neighbouring plants (buckwheat or redroot pigweed) and how these exudates affect redroot pigweed was investigated. Characterising root exudates in plant-plant interactions presents challenges, therefore a split-root system which enabled the application of differential treatments to parts of a single root system and non-destructive sampling was developed. Non-targeted metabolome profiling revealed that neighbour presence and identity induces systemic changes. Buckwheat and redroot pigweed neighbour presence upregulated 64 and 46 metabolites, respectively, with an overlap of only 7 metabolites. Root morphology analysis showed that, while the presence of redroot pigweed decreased the number of root tips in buckwheat, buckwheat decreased total root length and volume, surface area, number of root tips, and forks of redroot pigweed. Treatment with exudates (from the roots of buckwheat and redroot pigweed closely interacting) on redroot pigweed decreased the total root length and number of forks of redroot pigweed seedlings when compared to controls. These findings provide understanding of how plants modify their root exudate composition in the presence of neighbours and how this impacts each other's root systems.

Investigation of multidirectional toxicity induced by high-dose molybdenum exposure with Allium test.

In this study, the multifaceted toxicity induced by high doses of the essential trace element molybdenum in Allium cepa L. was investigated. Germination, root elongation, weight gain, mitotic index (MI), micronucleus (MN), chromosomal abnormalities (CAs), Comet assay, malondialdehyde (MDA), proline, superoxide dismutase (SOD), catalase (CAT) and anatomical parameters were used as biomarkers of toxicity. In addition, detailed correlation and PCA analyzes were performed for all parameters discussed. On the other hand, this study focused on the development of a two hidden layer deep neural network (DNN) using Matlab. Four experimental groups were designed: control group bulbs were germinated in tap water and application group bulbs were germinated with 1000, 2000 and 4000 mg/L doses of molybdenum for 72 h. After germination, root tips were collected and prepared for analysis. As a result, molybdenum exposure caused a dose-dependent decrease (p < 0.05) in the investigated physiological parameter values, and an increase (p < 0.05) in the cytogenetic (except MI) and biochemical parameter values. Molybdenum exposure induced different types of CAs and various anatomical damages in root meristem cells. Comet assay results showed that the severity of DNA damage increased depending on the increasing molybdenum dose. Detailed correlation and PCA analysis results determined significant positive and negative interactions between the investigated parameters and confirmed the relationships of these parameters with molybdenum doses. It has been found that the DNN model is in close agreement with the actual data showing the accuracy of the predictions. MAE, MAPE, RMSE and R2 were used to evaluate the effectiveness of the DNN model. Collective analysis of these metrics showed that the DNN model performed well. As a result, it has been determined once again that high doses of molybdenum cause multiple toxicity in A. cepa and the Allium test is a reliable universal test for determining this toxicity. Therefore, periodic measurement of molybdenum levels in agricultural soils should be the first priority in preventing molybdenum toxicity.

Immunohistochemical Detection of the Wall Components on the Example of Shoot Apical Meristem of Fagopyrum esculentum and Fagopyrum tataricum.

Immunohistochemistry is a method that allows the detection of individual components of cell walls in an extremely precise way at the level of a single cell and wall domains. The cell wall antibodies detect specific epitopes of pectins, arabinogalactan proteins (AGP), hemicelluloses, and extensins. The presented method visualization of the selected pectic and AGP epitopes using antibodies directed to wall components is described. The method of the analysis of the chemical composition of the wall is present on the example of the shoot apical meristems of Fagopurum esculentum and Fagopyrum tataricum. Recommended protocols for immunostaining and examination on fluorescence microscopy level are presented.

Cyanobacterial elicitor enhances the biomass of Mentha piperita L. and improves the production of high-value rosmarinic acid under in vitro culture of apical meristem.

BACKGROUND: Rosmarinic acid (RA), like other phenolic compounds, is sources of antioxidants and anti-inflammatory agents in medicinal plants. In vitro culture of plants can improve the medicinal plants' metabolite profile and phenolic compound quantity. To date, various methods have been proposed to increase this medicinal metabolite in plants, among which the use of bioelicitors can be mentioned. In the present study, a native isolate of heterocystous cyanobacteria, Nostoc spongiaeforme var. tenue ISB65, was used to stimulate the production of biomass and content of RA in Mentha piperita L. (peppermint) grown in vitro from apical meristem. Mentha piperita L. explants were inoculated in half strength Murashige and Skoog (1/2 MS) medium containing cyanobacterial lysate (CL). After 50 days of culturing, the growth indices, the content of photosynthetic pigments, and RA in control and treated plants were measured. RESULTS: CL inoculation resulted in a significant enhancement in the vegetative growth indices of peppermint, including root and shoot length, plant biomass and leaf number. The content of photosynthetic pigments also increased in cyanobacteria-treated plants. Inoculation with CL increased the RA content by 2.3-fold, meaning that the plants treated with CL had the highest RA content (7.68 mg. g- 1 dry weight) compared to the control (3.42 mg. g- 1 dry weight). Additionally, HPLC analysis revealed the presence of several auxins in CL. CONCLUSIONS: The presence of auxins and the chemical content of CL such as K+ and Ca2+, as regulators of metabolic pathways and molecular activities of cells, may be responsible for the enhanced growth and phenolic compounds of plants under tissue culture conditions. An improvement in RA content in the tissue culture of medicinal plants treated with CL was reported for the first time in this investigation.

Genotoxic effects induced by iprodione and tebuconazole in meristematic cells of Allium cepa: responses dependent on concentration and exposure time.

The present work explores the genotoxicity of the fungicides iprodione (IP) and tebuconazole (TB) using the Allium cepa assay as an in vivo biological model. Both short-term and long-term exposures were studied, revealing concentration- and time-dependent cytological and genotoxic effects. IP exhibited genotoxicity over a wider concentration range (5-50 µg/ml) and required 30 h of exposure, while TB showed genotoxicity at higher concentrations (10 and 30 µg/ml) within a 4-h exposure period. The study highlights the importance of assessing potential risks associated with fungicide exposure, including handling, disposal practices, and concerns regarding food residue. Moreover, the research underscores the genotoxic effects of IP and TB on plant cells and provides valuable insights into their concentration and time-response patterns.

Ferric reduction by a CYBDOM protein counteracts increased iron availability in root meristems induced by phosphorus deficiency.

To mobilize sparingly available phosphorus (P) in the rhizosphere, many plant species secrete malate to release P sorbed onto (hydr)oxides of aluminum and iron (Fe). In the presence of Fe, malate can provoke Fe over-accumulation in the root apoplast, triggering a series of events that inhibit root growth. Here, we identified HYPERSENSITIVE TO LOW P1 (HYP1), a CYBDOM protein constituted of a DOMON and a cytochrome b561 domain, as critical to maintain cell elongation and meristem integrity under low P. We demonstrate that HYP1 mediates ascorbate-dependent trans-plasma membrane electron transport and can reduce ferric and cupric substrates in Xenopus laevis oocytes and in planta. HYP1 expression is up-regulated in response to P deficiency in the proximal zone of the root apical meristem. Disruption of HYP1 leads to increased Fe and callose accumulation in the root meristem and causes significant transcriptional changes in roots. We further demonstrate that HYP1 activity overcomes malate-induced Fe accumulation, thereby preventing Fe-dependent root growth arrest in response to low P. Collectively, our results uncover an ascorbate-dependent metalloreductase that is critical to protect root meristems of P-deficient plants from increased Fe availability and provide insights into the physiological function of the yet poorly characterized but ubiquitous CYBDOM proteins.

In-vivo and in-silico studies to identify toxicity mechanisms of permethrin with the toxicity-reducing role of ginger.

In this study, the toxic effects of permethrin on Allium cepa L. and the protective role of Zingiber officinale rhizome extract (Zoex) were investigated. In this context, 6 different groups were formed. While the control group was treated with tap water, the groups II and III were treated with 10 µg/mL and 20 µg/mL Zoex, respectively, and the group IV was treated with 100 µg/L permethrin. The protective effect of Zoex against permethrin toxicity was studied as a function of dose, and groups V and VI formed for this purpose were treated with 10 µg/mL Zoex + 100 µg/L permethrin and 20 µg/mL Zoex + 100 µg/L permethrin, respectively. After 72 h of germination, cytogenetic, biochemical, physiological, and anatomical changes in meristematic cells of A. cepa were studied. As a result, permethrin application decreased the mitotic index (MI) and increased the frequency of micronuclei (MN), and chromosomal abnormalities. The increase in malondialdehyde (MDA), superoxide dismutase (SOD), and catalase (CAT) and the decrease in glutathione (GSH) indicate that permethrin causes oxidative damage. Compared to the control group, a 68.5% decrease in root elongation (p < 0.05) and an 81.8% decrease (p < 0.05) in weight gain were observed in the permethrin-treated group. It was found that the application of Zoex together with permethrin resulted in regression of all detected abnormalities, reduction in the incidence of anatomical damage, MN and chromosomal aberrations, and improvement in MI rates. The most significant improvement was observed in group VI treated with 20 µg/mL Zoex, and Zoex was also found to provide dose-dependent protection. The toxicity mechanism of permethrin was also elucidated by molecular docking and spectral studies. From the data obtained during the study, it was found that permethrin has toxic effects on A. cepa, a non-target organism, while Zoex plays a protective role by reducing these effects.

Soybean type-B response regulator GmRR1 mediates phosphorus uptake and yield by modifying root architecture.

Phosphorus (P) plays a pivotal role in plant growth and development. Low P stress can greatly hamper plant growth. Here, we identified a QTL (named QPH-9-1), which is associated with P efficiency across multiple environments through linkage analysis and genome-wide association study. Furthermore, we successfully cloned the underlying soybean (Glycine max) gene GmRR1 (a soybean type-B Response Regulator 1) that encodes a type-B response regulator protein. Knockout of GmRR1 resulted in a substantial increase in plant height, biomass, P uptake efficiency, and yield-related traits due to the modification of root structure. In contrast, overexpression of GmRR1 in plants resulted in a decrease in these phenotypes. Further analysis revealed that knockout of GmRR1 substantially increased the levels of auxin and ethylene in roots, thereby promoting root hair formation and growth by promoting the formation of root hair primordium and lengthening the root apical meristem. Yeast two-hybrid, bimolecular fluorescence complementation, and dual-luciferase assays demonstrated an interaction between GmRR1 and Histidine-containing Phosphotransmitter protein 1. Expression analysis suggested that these proteins coparticipated in response to low P stress. Analysis of genomic sequences showed that GmRR1 underwent a selection during soybean domestication. Taken together, this study provides further insights into how plants respond to low P stress by modifying root architecture through phytohormone pathways.

Benzophenone-3 sunscreen causes phytotoxicity and cytogenotoxicity in higher plants.

The benzophenone-3 (BP-3) sunscreen is recurrently released into the environment from different sources, however, evaluations of its adverse effects on plants do not exist in the literature. In this study, BP-3 was evaluated, at concentrations 2; 20, and 200 µg/L, regarding phytotoxicity, based on germination and root elongation in seeds, in Lactuca sativa L., Cucumis sativus L. and Allium cepa L., and phytotoxicity, cytogenotoxicity and oxidative stress in A. cepa bulb roots. The BP-3 concentrations, except for the 200 µg/L concentration in L. sativa, caused no significant reduction in seed germination. All concentrations tested significantly reduced the elongation of roots from seeds and roots from bulbs. The 20 and 200 µg/L concentrations caused oxidation in cells, disturbances in the cell cycle, and alterations in prophase and metaphase, as well as the induction of micronuclei, in A. cepa root meristems. Furthermore, the three concentrations induced a high number of prophases in root tips. Such disorders were caused by excess H2O2 and superoxide produced in cells due to exposure to BP-3, which triggered significant phytotoxicity, cytotoxicity, and genotoxicity in root meristems. Thus, the recurrent contamination of agricultural and non-agricultural soils with BP-3, even at a concentration of 2 µg/L, represents an environmental risk for plants. These results point to the impending need to set limits for the disposal of this sunscreen into the environment since BP-3 has been used in industry for several decades.

In silico interactions and deep neural network modeling for toxicity profile of methyl methanesulfonate.

In this study, the toxicity induced by the alkylating agent methyl methanesulfonate (MMS) in Allium cepa L. was investigated. For this aim, bulbs were divided into 4 groups as control and application (100, 500 and 4000 µM MMS) and germinated for 72 h at 22-24 °C. At the end of the germination period root tips were collected and made ready for analysis by applying traditional preparation methods. Germination, root elongation, weight, mitotic index (MI) values, micronucleus (MN) and chromosomal abnormality (CAs) numbers, malondialdehyde (MDA) levels, superoxide dismutase (SOD) and catalase (CAT) activities and anatomical structures of bulbs were used as indicators to determine toxicity. Moreover the extent of DNA fragmentation induced by MMS was determined by comet assay. To confirm the DNA fragmentation induced by MMS, the DNA-MMS interaction was examined with molecular docking. Correlation and principal component analyses (PCA) were performed to examine the relationship between all parameters and understand the underlying structure and relationships among these parameters. In the present study, a deep neural network (DNN) with two hidden layers implemented in Matlab has been developed for the comparison of the estimated data with the real data. The effect of MDA levels, SOD and CAT activities at 4 different endpoints resulting from administration of various concentrations of MMS, including MN, MI, CAs and DNA damage, was attempted to be estimated by DNN model. It is assumed that the predicted results are in close agreement with the actual data. The effectiveness of the model was evaluated using 4 different metrics, MAE, MAPE, RMSE and R2, which together show that the model performs commendably. As a result, the highest germination, root elongation, weight gain and MI were measured in the control group. MMS application caused a decrease in all physiological parameters and an increase in cytogenetic (except MI) and biochemical parameters. MMS application caused an increase in antioxidant enzyme levels (SOD and CAT) up to a concentration of 500 µM and a decrease at 4000 µM. MMS application induced different types of CAs and anatomical damages in root meristem cells. The results of the comet assay showed that the severity of DNA fragmentation increased with increasing MMS concentration. Molecular docking analysis showed a strong DNA-MMS interaction. The results of correlation and PCA revealed significant positive and negative interactions between the studied parameters and confirmed the interactions of these parameters with MMS. It has been shown that the DNN model developed in this study is a valuable resource for predicting genotoxicity due to oxidative stress and lipid peroxidation. In addition, this model has the potential to help evaluate the genotoxicity status of various chemical compounds. At the end of the study, it was concluded that MMS strongly supports a versatile toxicity in plant cells and the selected parameters are suitable indicators for determining this toxicity.

DNA fragmentation, chromosomal aberrations, and multi-toxic effects induced by nickel and the modulation of Ni-induced damage by pomegranate seed extract in Allium cepa L.

This study was designed to assess the recovery effect of pomegranate seed extract (PSEx) against nickel (Ni)-induced damage in Allium cepa. Except for the control group treated with tap water, five experimental groups were exposed to 265 mg L-1 PSEx, 530 mg L-1 PSEx, 1 mg L-1 NiCI2, 265 mg L-1 PSEx + 1 mg L-1 NiCI2, and 530 mg L-1 PSEx + 1 mg L-1 NiCI2, respectively. The toxicity of Ni was examined through the analysis of physiological (germination percentage, weight gain, and root length), cytotoxicity (mitotic index), genotoxicity (micronucleus, chromosomal anomalies, and Comet test), and biochemical (malondialdehyde, proline, chlorophyll a and chlorophyll b contents, the activities of superoxide dismutase and catalase) parameters. Meristematic cell defects were also investigated. The NiCl2-DNA interaction was evaluated through spectral shift analysis. Values of all physiological parameters, mitotic index scores, and chlorophyll contents decreased while micronucleus frequency, DNA tail percentage, chromosomal anomalies, proline, MDA, and enzyme activities increased following Ni administration. According to the tail DNA percentage scale, Ni application caused "high damage" to DNA. Ni-induced chromosomal anomalies were fragment, sticky chromosome, vagrant chromosome, bridge, unbalanced chromatin distribution, reverse polarization, and nucleus with bud. NiCl2-DNA interaction caused a hyperchromic shift in the UV/Vis spectrum of DNA by spectral profile analysis. Ni exposure impaired root meristems as evidenced by the formation of epidermis cell damage, flattened cell nucleus, thickened cortex cell wall, and blurry vascular tissue. Substantial recovery was seen in all parameters with the co-administration of PSEx and Ni. Recovery effects in the parameters were 18-51% and 41-84% in the 265 mg L-1 PSEx + 1 mg L-1 NiCI2 and 530 mg L-1 PSEx + 1 mg L-1 NiCI2 groups, respectively. The Comet scale showed that PSEx applied with Ni reduced DNA damage from "high" to "moderate." Ni-induced thickened cortex cell wall and blurry vascular tissue damage disappeared completely when 530 mg L-1 PSEx was mixed with Ni. PSEx successfully reduced the negative effects of Ni, which can be attributed to its content of antioxidants and bioactive ingredients.

WUSCHEL controls genotype-dependent shoot regeneration capacity in potato.

Plant cells can reprogram their fate. The combinatorial actions of auxin and cytokinin dedifferentiate somatic cells to regenerate organs, which can develop into individual plants. As transgenic plants can be generated from genetically modified somatic cells through these processes, cell fate transition is an unavoidable step in crop genetic engineering. However, regeneration capacity closely depends on the genotype, and the molecular events underlying these variances remain elusive. In the present study, we demonstrated that WUSCHEL (WUS)-a homeodomain transcription factor-determines regeneration capacity in different potato (Solanum tuberosum) genotypes. Comparative analysis of shoot regeneration efficiency and expression of genes related to cell fate transition revealed that WUS expression coincided with regeneration rate in different potato genotypes. Moreover, in a high-efficiency genotype, WUS silencing suppressed shoot regeneration. Meanwhile, in a low-efficiency genotype, regeneration could be enhanced through the supplementation of a different type of cytokinin that promoted WUS expression. Computational modeling of cytokinin receptor-ligand interactions suggested that the docking pose of cytokinins mediated by hydrogen bonding with the core residues may be pivotal for WUS expression and shoot regeneration in potatoes. Furthermore, our whole-genome sequencing analysis revealed core sequence variations in the WUS promoters that differentiate low- and high-efficiency genotypes. The present study revealed that cytokinin responses, particularly WUS expression, determine shoot regeneration efficiency in different potato genotypes.

DNA fragmentation and multifaceted toxicity induced by high-dose vanadium exposure determined by the bioindicator Allium test.

In this study, the toxicity of vanadium (VCI3) in Allium cepa L. was studied. Germination-related parameters, mitotic index (MI), catalase (CAT) activity, chromosomal abnormalities (CAs), malondialdehyde (MDA) level, micronucleus (MN) frequency and superoxide dismutase (SOD) activity were investigated. The effects of VCI3 exposure on the DNA of meristem cells were investigated with the help of comet assay, and the relationships between physiological, cytogenetic and biochemical parameters were revealed by correlation and PCA analyses. A. cepa bulbs were germinated with different concentrations of VCI3 for 72 h. As a result, the maximum germination (100%), root elongation (10.4 cm) and weight gain (6.85 g) were determined in the control. VCI3 treatment caused significant decreases in all tested germination-related parameters compared to the control. The highest percentage of MI (8.62%) was also observed in the control. No CAs were found in the control, except for a few sticky chromosomes and unequal distribution of chromatin (p > 0.05). VCI3 treatment caused significant decreases in MI and increases in the frequencies of CAs and MN, depending on the dose. Similarly, the comet assay showed that DNA damage scores increased with increasing VCI3 doses. The lowest root MDA (6.50 µM/g) level and SOD (36.7 U/mg) and CAT (0.82 OD240nmmin/g) activities were also measured in the control. VCI3 treatment caused significant increases in root MDA levels and antioxidant enzyme activities. Besides, VCI3 treatment induced anatomical damages such as flattened cell nucleus, epidermis cell damage, binuclear cell, thickening in the cortex cell wall, giant cell nucleus, damages in cortex cell and unclear vascular tissue. All examined parameters showed significant negative or positive correlations with each other. PCA analysis confirmed the relations of investigated parameters and VCI3 exposure.

Use of the Allium cepa Model to Assess the Cytogenotoxicity of Luffariella herdmani Marine Sponge Extract.

Marine sponge extracts are known to contain potentially toxic compounds that have biological activities of possible pharmacological interest. Thus, it is vital that biological models are used for the preliminary toxicity screening of such extracts. The present study reports the use of Allium cepa, a low-cost plant-based in vivo model, to assess the cytotoxicity and genotoxicity of Luffariella herdmani marine sponge crude extract (SCE). Pre-germinated onion bulbs, exposed for 96 hours to different concentrations of SCE (ranging from 0.3125 to 20 µg/ml), were used to determine general cytotoxicity. Root length as well as morphological abnormalities were recorded. Genotoxicity was assessed by exposing the root tips to SCE (0.3125-20 µg/ml) and the appropriate controls for 48 hours, and then staining with acetocarmine. The Mitotic Index (MI), Mitotic Phase Indices (MPIs) and chromosomal aberrations were evaluated and recorded. SCE inhibited A. cepa root growth (EC50 = 10.34 µg/ml) and elicited a mitodepressive effect (LC50 = 1.95 µg/ml) in a dose-dependent and significant manner. In addition, macroscopic alterations as well as chromosomal aberrations were detected. Overall, our findings indicate that L. herdmani crude extract exhibits cytotoxic and genotoxic activity, suggesting that it might contain substances with anti-proliferative/anticancer potential that could be subject to further characterisation.

Assessing the combined toxic effects of metaldehyde mollucide.

The excessive use of metaldehyde in agriculture to combat mollusks endangers both the environment and non-target organisms. The aim of this study is to investigate the toxicity caused by metaldehyde in Allium cepa with the help of physiological, cytogenetic, biochemical and anatomical parameters. Also, DNA fragmentation caused by metaldehyde in root tip cells was measured by the "Comet Assay" method. The control group was germinated with tap water and the application groups were germinated with 20 mg/L metaldehyde, 40 mg/L metaldehyde, 100 mg/L metaldehyde and 200 mg/L metaldehyde for 72 h. The results of the physiological parameters showed that metaldehyde had a growth-limiting effect in A. cepa, depending on the application dose. According to root elongation levels, the EC50 (effective concentration) value for metaldehyde was 60.6 mg/L in A. cepa. As the treatment dose increased, the incidence of micronucleus and chromosomal aberrations gradually increased while mitotic index decreased. Metaldehyde exposure induced damages such as sticky chromosome, fragment, unequal distribution of chromatin, reverse polarization, bridge, and multipolar anaphase. In addition, metaldehyde caused cell damage in epidermis and cortex, thickening of the cortex cell wall and flattened cell nucleus in root meristem. Increasing doses of metaldehyde application also increased malondialdehyde levels, superoxide dismutase and catalase activities. As a result, it has been determined that the toxicity of metaldehyde in plants is versatile and the A. cepa test material is a suitable biological indicator to determine this toxicity.

Cytogenotoxic effects of 3-epicaryoptin in Allium cepa L. root apical meristem cells.

Diterpenoid 3-epicaryoptin (C26H36O9) is abundant in the leaves of Clerodendrum inerme, a traditionally used medicinal plant, and has insect antifeedant activities. Here, we aim to explore the cytogenotoxic effects of compound 3-epicaryoptin in Allium cepa root apical meristem cells. 3-epicaryoptin (concentrations of 100, 150, and 200 µg mL-1) and the standard compound colchicine (200 µg mL-1) were applied to A. cepa roots for 2, 4, and 4 + 16 h (4-h treatment followed by 16-h recovery). Cytogenotoxicity was analyzed by studying the root growth retardation (RGR), mitotic index (MI), and chromosomal aberrations. The result showed statistically significant (p < 0.01), concentration-dependent RGR effects of 3-epicaryoptin treatment compared with the negative control. A study of cell frequency in different phases of cell division observed a significant (p < 0.001) increase in the metaphase cell percentage (66.2 ± 0.58%, 150 µg mL-1), which subsequently caused an increase in the frequency of MI (12.29 ± 0.34%, 150 µg mL-1) at 4 h of 3-epicaryoptin treatment and that was comparable with the colchicine action. The cytological study revealed that the 3-epicaryoptin treatment could induce different types of chromosomal abnormalities, such as colchicine-like metaphase, vagrant chromosomes, sticky chromosomes, anaphase bridge, lagging chromosomes, multipolar anaphase-telophase, and an increased frequency of micronuclei and polyploid cells. These findings indicate that 3-epicaryoptin is cytogenotoxic, and thus, C. inerme should be used with caution in traditional medicine.

Lycopene: an antioxidant product reducing dithane toxicity in Allium cepa L.

The current study was undertaken to assess the attenuating potential of lycopene against Dithane toxicity in Allium cepa L. roots. A. cepa bulbs were arranged in 6 groups. The control group was treated with tap water while the other groups were treated with 215 mg/L lycopene, 430 mg/L lycopene, 500 mg/L Dithane, 500 mg/L Dithane + 215 mg/L lycopene and 500 mg/L Dithane + 430 mg/L lycopene, respectively. When the treatments were completed, growth inhibition, biochemical, genotoxicity and meristematic cell injury analyses were performed. Lycopene did not cause any toxic effect when applied alone. While rooting percentage, root elongation, weight gain and mitotic index (MI) decreased in response to Dithane exposure, the frequency of micronucleus (MN) and chromosomal abnormalities (CAs) in addition to malondialdehyde (MDA) level and the catalytic activities of superoxide dismutase (SOD) and catalase (CAT) increased. Dithane promoted fragment, sticky chromosome, vagrant chromosome, unequal distribution of chromatin, bridge, nucleus bud and reverse polarization formation in meristem cells. Dithane also provoked meristematic cell injuries, including indistinct appearance of vascular tissue, epidermis cell damage and flattened cell nucleus. Lycopene mitigated all damage types, depending on the lycopene dose applied with Dithane. Hence, the data analysis revealed that lycopene provides exceptional antioxidant protection against the fungicide Dithane, which has devastating toxic potential.

Cyto-Genotoxic and Behavioral Effects of Flubendiamide in Allium cepa Root Cells, Drosophila melanogaster and Molecular Docking Studies.

Flubendiamide (FLB) is an insecticide that is commonly employed to control pests on a variety of vegetables and fruits, with low toxicity for non-target organisms. However, due to its widespread use, the environmental risks and food safety have become major concerns. In this study, the toxicity potential of FLB was studied in the model organisms, Allium cepa and Drosophila melanogaster. The cyto-genotoxic effects of FLB on the root growth, mitotic index (MI), chromosomal aberrations (CAs) and deoxyribonucleic acid (DNA) damage in A. cepa root meristematic cells were investigated using the root growth inhibition Allium test and Comet assays. FLB caused CAs in the form of disturbed ana-telophase, chromosome laggards, stickiness, anaphase-bridge and polyploidy depending on the concentration and the exposure time. The toxicity and genotoxicity of FLB at various doses (0.001, 0.01, 0.1 and 1 mM) on D. melanogaster were investigated from the point of view of larval weight and movement, pupal formation success, pupal position, emergence success and DNA damage, respectively. FLB exposure led to a significant reduction of the locomotor activity at the highest concentration. While DNA damage increased significantly in the FLB-treated onions depending on the concentration and time, DNA damage in the FLB-treated D. melanogaster significantly increased only at the highest dose compared to that which occurred in the control group. Moreover, to provide a mechanistic insight into the genotoxic and locomotion-disrupting effects of FLB, molecular docking simulations of this pesticide were performed against the DNA and diamondback moth (DBM) ryanodine receptor (RyR) Repeat34 domain. The docking studies revealed that FLB binds strongly to a DNA region that is rich in cytosine-guanine-adenine bases (C-G-A) in the minor groove, and it displayed a remarkable binding affinity against the DBM RyR Repeat34 domain.

Spectral shift supported epichlorohydrin toxicity and the protective role of sage.

In this study, the toxicity of epichlorohydrin, a chemical intermediate, was investigated by using Allium cepa L. test material as a bio-indicator. In addition, the protective role of sage leaf extract (Slex) against this toxicity was investigated. Toxicity was handled with the help of physiological (germination percentage, root elongation, and weight gain), cytogenetic (mitotic index = MI, micronucleus = MN, and chromosomal abnormalities = CAs), biochemical (malondialdehyde = MDA, superoxide dismutase = SOD, and catalase = CAT), and anatomical (root meristem cell damages) parameters. A. cepa bulbs were divided into 6 groups (1 control, 5 applications). The bulbs in the control group were treated with tap water, and the bulbs in the application group were treated with epichlorohydrin at a dose of 100 mg/L and Slex at two different doses (190 mg/L and 380 mg/L) and germinated. Germination process was continued uninterruptedly for 72 h in all groups. At the end of the period, physiological parameter measurements were carried out in the bulbs. In addition, root tips were collected and made ready for cytogenetic, biochemical, and anatomical measurements and microscopic observations. As a result, exposure to epichlorohydrin caused statistically significant (p < 0.05) decreases in germination percentage, root length, weight gain, and MI, and statistically significant (p<0.05) increases in MN frequency, CA numbers, MDA level, SOD, and CAT enzyme activities. Epichlorohydrin exposure induced CAs such as fragment, sticky chromosome, unequal distribution of chromatin, reverse polarization, and disordered mitosis in root meristem cells. The toxicity of epichlorohydrin was due to its interaction with DNA, and this interaction was confirmed by the spectral shift in the DNA spectrum. In addition, epichlorohydrin caused anatomical damages such as epidermis cell damage, cortex cell damage, thickening of the cortex cell wall, and flattened cell nuclei in root meristem cells. The application of Slex together with epichlorohydrin decreased the toxicity of epichlorohydrin and again caused statistically significant (p < 0.05) improvements in the values of all the parameters examined. In other words, germination percentage, root length, weight gain, and MI increased again and MN frequency, CAs numbers, MDA level, SOD, and CAT enzyme activities decreased. It was determined that this improvement was even more pronounced at 380 mg/L dose of Slex. As a result, it was determined that epichlorohydrin caused multiple-toxicity for the investigated indicator organism, and Slex had a reducing role in this toxicity. For this reason, Slex should be included in the daily diet as an antioxidant beverage in order to protect from the toxicity of chemical agents exposed in daily life or to reduce their effects.

Transcriptome-wide identification of NAC (no apical meristem/Arabidopsis transcription activation factor/cup-shaped cotyledon) transcription factors potentially involved in salt stress response in garlic.

Soil salinity has been an increasing problem worldwide endangering crop production and human food security. It is an ideal strategy to excavate stress resistant genes and develop salt tolerant crops. NAC (no apical meristem/Arabidopsis transcription activation factor/cup-shaped cotyledon) transcription factors have been demonstrated to be involved in salt stress response. However, relevant studies have not been observed in garlic, an important vegetable consumed in the world. In this study, a total of 46 AsNAC genes encoding NAC proteins were identified in garlic plant by transcriptome data. Phylogenetic analysis showed that the examined AsNAC proteins were clustered into 14 subgroups. Motif discovery revealed that the conserved domain region was mainly composed of five conserved subdomains. Most of the genes selected could be induced by salt stress in different tissues, indicating a potential role in salt stress response. Further studies may focus on the molecular mechanisms of the AsNAC genes in salt stress response. The results of the current work provided valuable resources for researchers aimed at developing salt tolerant crops.