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Effects of plant growth regulator and chelating agent on the phytoextraction of heavy metals by Pfaffia glomerata and on the soil microbial community
2021
Huang, Rong | Cui, Xiaoying | Luo, Xianzhen | Mao, Peng | Zhuang, Ping | Li, Yongxing | Li, Yingwen | Li, Zhian
Pfaffia glomerata is a candidate for the remediation of heavy metal-contaminated soil, but phytoremediation efficiency requires enhancement. In this study, we evaluated how application of DA-6, EDTA, or CA affected the growth and heavy metal accumulation of P. glomerata and soil microorganisms. We found that P. glomerata removed more Cd and Zn than Pb or Cu from contaminated soil. When compared to the control, application of DA-6, CA, or CA + DA-6 increased plant biomass and increased stem Cd concentration by 1.28-, 1.20-, and 1.31-fold respectively; increased leaf Cd concentration by 1.25-, 1.28-, and 1.20-fold, respectively; and increased the total quantity of Cd extracted by 1.37-, 1.37-, and 1.38-fold, respectively. When compared to the control, application EDTA or EDTA + DA-6 significantly increased the soil available metal and Na concentrations, which harmed plant growth. Application of EDTA or EDTA + DA-6 also significantly decreased the Cd concentration in roots and stems. 16S rRNA high-throughput sequencing analysis revealed that application of EDTA or CA alone to soil significantly reduced the richness and diversity of soil bacteria, while foliar spraying of DA-6 combined with EDTA or CA slightly alleviated this reduction. EDTA or CA addition significantly changed the proportion of Actinobacteria and Proteobacteria. In addition, EDTA or CA addition caused changes in soil properties (e.g. heavy metal availability, K concentration, Na concentration, soil pH, soil CEC, and soil DOC concentration) that were associated with changes in the bacterial community. EDTA addition mainly affected the soil bacterial community by changing soil DOC concentration, the soil available Pb and Na concentration, and CA addition mainly affected the soil bacterial community by changing the soil available Ca concentration.
Afficher plus [+] Moins [-]Integrated application of plant bioregulator and micronutrients improves crop physiology, productivity and grain biofortification of delayed sown wheat
2022
Delay sowing of wheat is a common problem in Punjab that exacerbates serious yield loss. To reduce yield loss and improve yield, different combinations of foliar-applied bioregulator and micronutrients, control (CK), zinc (Zn), boron (B), thiourea (TU), Zn + B (ZnB), Zn + TU (ZnTU), B + TU (BTU), Zn + B + TU (ZnBTU) were applied at booting and grain filling stages in delayed sown wheat in 2017–18 and 2018–19. The results showed that ZnBTU treatment significantly increased leaf area index by 25.06% and 23.21%, spike length by 15.11% and 19.65% in 2017 and 2018, respectively, compared to CK. The ZnBTU treatment also increased 1000-grain weight by 21.96% and 22.01% in 2017 and 2018, respectively, compared to CK. Similarly, higher Zn, B and N contents in straw and grain were recoded for ZnBTU treatment which was statistically similar to ZnB and ZnTU treatments. Overall, ZnBTU treatment also increased the photosynthetic rate, transpiration rate, stomatal conductance by 46.67%, 26.03%, 76.25% and decreased internal CO₂ by 28.18%, compared to CK, respectively. Moreover, ZnBTU also recorded the highest grain yield in 2017–18 (25.05%) and 2018–19 (28.49%) than CK. In conclusion, foliar application of ZnBTU at the booting and grain filling stages of delayed sown wheat could be a promising strategy to increase grain yield.
Afficher plus [+] Moins [-]Ecotoxicity of polyelectrolyte formulations in water and soil matrices
2022
Yakimenko, Olga | Ziganshina, Aliya | Terekhova, Vera | Panova, Irina | Gladkova, Marina | Timofeev, Mikhail | Yaroslavov, Alexander
Interpolyelectrolyte complexes (IPECs) formed by the interaction of two oppositely charged polyelectrolytes have been proposed as soil structure stabilizers. However, little is known about the environmental safety of IPECs. The goal of this study was to investigate the toxicity of a positively charged IPEC formed by two commercial polymers, namely the cationic biopolymer poly(diallyldimethylammonium chloride) (PDDA) and the anionic biopolymer lignohumate (LH), a humic-based plant growth promoter. Toxicity was assessed using cultures of the bacteria Escherichia coli, the ciliate Paramecium caudatum, mammalian (Bos taurus) spermatozoa in vitro, and three plant species (Sinapis alba, Raphanus sativus, and Triticum durum). The responses of test organisms were evaluated in contact with (1) polymer and water and (2) polymer and soil. In water, PDDA and IPEC were highly toxic to bacteria and ciliates at all concentrations and less toxic to mammalian cells. Higher plants were less sensitive to the polymers, and the toxicity progressively decreased in the order PDDA > IPEC > LH. In soil matrices; the phytotoxicity of PDDA and IPEC was found to be quite low, and none of the polymers was toxic to plants at concentrations that allowed the formation of polymeric soil crusts against erosion. This is because the toxicity of cationic polymers decreases as they enter the soil matrix and bind to organic matter and minerals.
Afficher plus [+] Moins [-]Evaluation of Multiple Organ Dysfunction Score (MODS) and the Sequential Organ Failure Assessment (SOFA) score as in-hospital outcome predictors among cases of hydrogen cyanamide exposure: a cross-sectional study
2021
Sharif, Asmaa Fady | Fayed, Manar Maher
Dormex is widely used as a plant growth regulator in developing countries such as Egypt as well as worldwide. Despite the widespread use of Dormex, little is known about the exact mechanism of action and toxic profile. The current study aims to outline the factors that predict in-hospital outcome and the need for intensive care unit (ICU) admission among the patients who presented with acute hydrogen cyanamide exposure as well as to evaluate the roles of the Multiple Organ Dysfunction Score (MODS) and the Sequential Organ Failure Assessment (SOFA) score as unfavorable outcome predictors. This is a retrospective cross-sectional study including all cases diagnosed with acute hydrogen cyanamide exposure who presented to the Tanta Poison Control Center during the past 6 years (January 1, 2015–January 1, 2020). Patient data were collected in a case report form, including the history of exposure, clinical data, laboratory investigations, and radiologic studies. Four scoring systems were carried out upon presentation: the Glasgow Coma Scale, poison severity score, MODS, and SOFA score. Thirty-five patients were enrolled in the current study. Most of the presented cases were males exposed unintentionally in an occupational setting. The mean participant age was 34.1 ± 15.51 years. The most common presenting complaints were throat irritation in all cases, vomiting and hallucinations presented equally in 68.6%, and headache occurred in 51.4%, whereas skin and mucous membrane burn was present in 40% of cases. Patients showing one or more of the following criteria were expected to have an urgent need for ICU admission: MODS >3.5, SOFA >4.5, length of hospital stay >30 hours, prothrombin time >14.75 seconds, serum glutamic pyruvic transaminase >67.5 U/L, and serum glutamic oxaloacetic transaminase >58.5 U/L. When the length of hospital stay was combined with the four scoring systems, only MODS yielded a significant prediction. Study results indicate that MODS and SOFA scores are considered excellent outcome predictors; MODS is more accurate, specific, and treatment independent, whereas the use of the SOFA score is more feasible with simple cardiovascular function assessment.
Afficher plus [+] Moins [-]Lead Toxicity in Cereals and Its Management Strategies: a Critical Review
2018
Rizwan, Muhammad | Ali, Shafaqat | Rehman, MuhammadZia ur | Javed, MuhammadRizwan | Bashir, Arooj
Cereal grains such as wheat, rice, and maize are widely consumed as a staple food worldwide. Lead (Pb) is one of the non-essential trace elements and its toxicity in crops especially cereals is a widespread problem. The present review highlighted Pb toxicity in cereal and management strategies to reduce its uptake in plants. Lead toxicity reduced the cereal growth, photosynthesis, nutritional value, yield, and grain quality. The response of cereals to excess varies with plant species, levels of Pb in soil, and growth conditions. Reducing Pb bioavailability in the soil is a viable approach due to its non-degradability either by microbes, chemicals, or other means. Cultivation of low Pb-accumulating cultivars may reduce the risk of Pb toxicity in plants and humans via the food chain. Use of plant growth regulators, microbes, organic, and inorganic amendments might be promising techniques for further decreasing Pb contents in shoot and grains. Soil amendments along with selecting low Pb-accumulating cultivars might be a feasible approach to get cereal grains with low Pb concentrations. Furthermore, most of the studies have been conducted under controlled conditions either in hydroponic or pots and less is known about the effects of Pb management approaches under ambient field conditions.
Afficher plus [+] Moins [-]Dermal exposure assessment to trinexapac-ethyl: a case study of workers in golf course in Hawaii, USA
2021
Wang, Xu | Murison, Jessica | Wang, Jun | Leong, Gladys | Wu, Zhichao | Li, Qingxiao
Trinexapac-ethyl (TE) was more widely used in golf course worldwide. As a plant growth regulator, it inhibited grass development and delayed grass cutting date. Direct contact with TE by workers that handle and apply these agents can lead to harmful effects depending on the exposure dosage and duration. Many studies have focused on the growth regulation of TE in plants, while its health risks to human beings were rarely reported. Here, we investigated the risk assessment of workers directly dermal exposed to TE by using some absorbent paper patches. The exposure intensity (EI) and potential dermal exposure (PDE) of worker body sections were obtained, and different exposure patterns were compared. The EI of each body section among mixing/loading, hand-held power sprayer, and manual sprayer workers was ranging from 7.22 to 73.0 pg cm⁻². The maximum EI of TE was found on hands of manual sprayers, while the minimum EI of TE was recorded on upper arms of mixing and loading workers. The maximum contribution sections was 29% for the chest and back from mixing/loading workers, 40% for the chest and back from hand-held power sprayers, and 32% for the thigh from manual sprayers. The unit weight potential dermal exposure (UWPDE) of hand-held power sprayers was 60% lower than that of manual sprayers, indicating that hand-held power sprayers were safer than those of manual sprayers. These findings revealed that trinexapac-ethyl posed relatively higher exposure risks to manual sprayer workers than other operator workers in golf course, mainly responsible for body sections of the chest and back and thigh.
Afficher plus [+] Moins [-]Investigating the effect of methyl jasmonate and melatonin on resistance of Malus crabapple ‘Hong Jiu’ to ozone stress
2019
Qiu, Yanfen | An, Kai | Sun, Jingjing | Chen, Xuesen | Gong, Xiaojun | Ma, Li | Wu, Shuqing | Jiang, Shenghui | Zhang, Zongying | Wang, Yanling
Ozone (O₃) is an adverse environmental factor posing damage to ornamental plants. Thus, it is important to seek an effective way of enhancing plant tolerance to O₃-induced damage. Methyl jasmonate (MJ) and melatonin (MT) are plant growth regulators (PGRs) involved in plant abiotic stress responses. In this study, compared with the control group of plants without ozone, the influence of exogenous MJ (0, 10, 50, 100, and 150 μM) and MT (0, 0.1, 0.5, 2.5, and 12.5 μM) on the resistance of Malus crabapple ‘Hong Jiu’ was evaluated under O₃ stress (100 ± 10 nL/L for 3 h). Our data revealed that levels of MDA were significantly enhanced following O₃ treatment compared with plants without O₃. O₃ induced the activities of antioxidant enzymes and the accumulation of non-enzymatic antioxidants. While lower malondialdehyde (MDA) content, greater activities of antioxidant enzymes, and higher levels of soluble protein and non-enzymatic antioxidants were observed in PGRs-pretreated plants than in non-PGRs-pretreated plants under O₃ stress. Based on the above results and air pollution tolerance index (APTI), an exogenous supply of MJ and MT to Malus crabapple ‘Hong Jiu’ seedlings was protective for O₃-induced toxicity. The present study provides new insights into the mechanisms of MJ and MT amelioration of O₃-induced oxidative stress damages in Malus crabapple ‘Hong Jiu.’
Afficher plus [+] Moins [-]Aged garlic extract rescues ethephon-induced kidney damage by modulating oxidative stress, apoptosis, inflammation, and histopathological changes in rats
2021
Albrakati, Ashraf
Ethephon is an organophosphorus plant growth regulator used to accelerate the ripening process and decrease the duration of cultivation. Here, the potential protective role of aged garlic extract (AGE) was investigated against ethephon-mediated nephrotoxicity. Four experimental groups were established (n = 15), including control, AGE (250 mg/kg), ethephon (200 mg/kg), and AGE + ethephon. In the current work, kidney function parameters (urea, creatinine, and KIM-1) along with oxidative stress biomarkers, nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1, glutathione, and its related enzymes, superoxide dismutase, catalase, malondialdehyde, and nitric oxide, were determined. The expression of inflammatory mediators namely tumor necrosis factor alpha, interleukin 1 beta, nuclear factor kappa B, and apoptotic markers (caspase 3, Bax, and Bcl2) were determined in the renal tissue. Additionally, the histopathological alterations in response to treatments were examined. Ethephon exposure increased the levels of kidney function markers along with relative kidney weight coupled with histological changes in the kidney tissue. Additionally, ethephon increased the levels of the tested pro-oxidant markers and decreased the antioxidant indices, resulting in oxidative damage to renal tissues. An elevation in the pro-inflammatory mediators was also recorded following ethephon intoxication. Furthermore, renal cell loss was observed through histological examinations and biochemical measurements upon ethephon administration. On the other hand, AGE significantly ameliorated the molecular, biochemical, and structural changes elicited by ethephon. These findings suggest that AGE may be used to decrease or prevent the side effects of ethephon exposure in kidneys, through the activation of Nrf2 and inhibition of inflammation and apoptotic response.
Afficher plus [+] Moins [-]Application of paclobutrazol: a strategy for inducing lodging resistance of wheat through mediation of plant height, stem physical strength, and lignin biosynthesis
2018
Kāmrān, Muḥammad | Ahmad, Irshad | Wu, Xiaorong | Liu, Tiening | Ding, Ruixia | Han, Qingfang
Lodging is a major constraint contributing to poor grain yield and quality of wheat (Triticum aestivum L.) worldwide. The use of plant growth regulators is becoming a foremost agro-chemical approach for minimizing the risk of lodging in cereal crops. The present study was conducted to examine the effects of the paclobutrazol application on culm physical strength, lignin content, and lodging resistance of wheat. Wheat seeds were soaked in paclobutrazol at the concentrations of 0 (CK, as control), 200 (PB1), 300 (PB2), and 400 (PB3) mg L⁻¹. Our results showed that paclobutrazol resulted in a dose-dependent decrease of plant height, internode length, and center of gravity height. Paclobutrazol treatments evidently increased the culm diameter, culm filling degree, and wall thickness of basal internodes, resulting in greater stalk-breaking strength and lodging resistance index (CLRI), where their maximum values were obtained with PB1 treatment. In addition, the activities of lignin-related enzymes were improved by paclobutrazol, particularly at low concentration, which increased the lignin accumulation of the basal internodes of wheat, subsequently improving the capability of stalk lodging resistance. Moreover, the correlation analysis revealed significant correlations between stem diameter, culm filling degree, and lignin with stalk bending strength and CLRI. The paclobutrazol concentration ≥ 300 mg L⁻¹ (PB2 and PB3 treatments) showed inhibitive effects on various culm morphological traits. These results suggest that not only the plant height, but also the lignin contents and physical strength of internodes are closely related with the lodging resistance of wheat, and reduction in plant height along with improved culm morphological characteristics and higher lignin accumulation in basal internodes could effectively relieve the risk of lodging.
Afficher plus [+] Moins [-]Assessment of the applicability of a “toolbox” designed for microbially assisted phytoremediation: the case study at Ingurtosu mining site (Italy)
2014
Sprocati, Anna Rosa | Alisi, Chiara | Pinto, Valentina | Montereali, Maria Rita | Marconi, Paola | Tasso, Flavia | Turnau, Katarzyna | De Giudici, Giovanni | Goralska, Katarzyna | Bevilacqua, Marta | Marini, Federico | Cremisini, Carlo
The paper describes the fieldwork at the Italian test site of the abandoned mine of sphalerite and galena in Ingurtosu (Sardinia), with the aim to assess the applicability of a “toolbox” to establish the optimized techniques for remediation of soils contaminated by mining activities. A preliminary characterization—including (hydro)geochemistry, heavy metal concentration and their mobility in soil, bioprospecting for microbiology and botany—provided a data set for the development of a toolbox to deliver a microbially assisted phytoremediation process. Euphorbia pithyusa was selected as an endemic pioneer plant to be associated with a bacterial consortium, established with ten selected native strains, including metal-tolerant bacteria and producers of plant growth factors. The toolbox was firstly assessed in a greenhouse pot experiment. A positive effect of bacterial inoculum on E. pithyusa germination and total plant survival was observed. E. pithyusa showed to be a well-performing metallophyte species, and only inoculated soil retained a microbial activity with a high functional diversity, expanding metabolic affinity also towards root exudates. These results supported the decision to proceed with a field trial, investigating different treatments used singly or in combination: bioaugmentation with bacterial consortia, mycorrhizal fungi and a commercial mineral amendment. Microbial activity in soil, plant physiological parameters and heavy metal content in plants and in soil were monitored. Five months after the beginning, an early assessment of the toolbox under field conditions was carried out. Despite the cold season (October–March), results suggested the following: (1) the field setup as well as the experimental design proved to be effective; (2) plant survival was satisfactory; (3) soil quality was increased and bioaugmentation improved microbial activity, expanding the metabolic competences towards plant interaction (root exudates); and (4) multivariate analysis supported the data provided that the proposed toolbox can be established and the field trial can be carried forward.
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