scholarly journals Phytotoxicity in Seedlings of Rhizophora mangle (L.) Exposed to 2,4-Dichlorophenoxyacetic Acid under Experimental Conditions

2021 ◽  
Vol 9 (12) ◽  
pp. 1417
Author(s):  
Carlos A. Chan-Keb ◽  
Claudia M. Agraz-Hernández ◽  
Román A. Pérez-Balan ◽  
Eduardo J. Gutiérrez-Alcántara ◽  
Raquel Muñiz-Salazar ◽  
...  
Keyword(s):  
Chlorophyll A ◽  
Biomass Production ◽  
Agricultural Practices ◽  
Rhizophora Mangle ◽  
Dichlorophenoxyacetic Acid ◽  
Inhibitory Effects ◽  
Experimental Conditions ◽  
Environmental Goods ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
The Impact

Mangroves are considered one of the most productive ecosystems worldwide, providing multiple environmental goods and services; however, in recent years, there have been modifications and deterioration in the structure and function of these ecosystems, caused by various natural events and anthropic activities, such as the construction of roads, wastewater discharge, unsustainable livestock, and agricultural practices, as well as the impact of chemicals, such as heavy metals, oil spills, and the use of herbicides. In this research, phytotoxic effects on seedlings of Rhizophora mangle were evaluated at an exposure of five dilutions w/v (5%, 10%, 25%, 50%, and 100%) of the commercial presentation of 2,4-dichlorophenoxyacetic acid (2,4-D). Propagules grown in a greenhouse under local tidal regimes were used, so the growth of stem diameter, height, biomass production in root, leaves, and stems, as well as the concentration of chlorophyll a of the exposed seedlings were measured. The comparison of these parameters in seedlings with only seawater presented significant differences (p ≤ 0.05) and inhibitory effects on growth (diameter), the stem concentration of chlorophyll a, and the production of biomass of leaves, stems, and roots. The inhibitory effect of exposure to 2,4-D on chlorophyll production and root biomass is highlighted, with an average decrease of 45% relative to the control. The sensitivity of the Rhizophora mangle seedlings to the applied concentrations of herbicide evidence the inhibitory effects on the morphological variables of biomass production and chlorophyll a production in mangrove leaves.

scholarly journals Impact of Ionic Liquids on Induction of Wheat Microspore Embryogenesis and Plant Regeneration

Agronomy ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 839
Author(s):  
Dorota Weigt ◽  
Idzi Siatkowski ◽  
Magdalena Magaj ◽  
Agnieszka Tomkowiak ◽  
Jerzy Nawracała
Keyword(s):  
Ionic Liquids ◽  
Plant Regeneration ◽  
Positive Impact ◽  
Microspore Embryogenesis ◽  
Green Plant ◽  
Induction Medium ◽  
Dichlorophenoxyacetic Acid ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
The Impact

Ionic liquids are novel compounds with unique chemical and physical properties. They can be received based on synthetic auxins like 2,4-dichlorophenoxyacetic acid or dicamba, which are commonly used hormones in microspore embryogenesis. Nevertheless, ionic liquids have not been adapted in plant in vitro culture thus far. Therefore, we studied the impact of ionic liquids on the ability to undergo microspore embryogenesis in anther cultures of wheat. Two embryogenic and two recalcitrant genotypes were used for this study. Ten combinations of ionic liquids and 2,4-dichlorophenoxyacetic acid were added to the induction medium. In most cases, they stimulated induction of microspore embryogenesis and green plant regeneration more than a control medium supplemented with only 2,4-dichlorophenoxyacetic acid. Two treatments were the most favorable, resulting in over two times greater efficiency of microspore embryogenesis induction in comparison to the control. The effect of breaking down the genotype recalcitrance (manifested by green plant formation) was observed under the influence of 5 ionic liquids treatments. Summing up, ionic liquids had a positive impact on microspore embryogenesis induction and green plant regeneration, increasing the efficiency of these phenomena in both embryogenic and recalcitrant genotypes. Herbicidal ionic liquids can be successfully used in in vitro cultures.

scholarly journals Auxins Regulations of Branched Spike Development and Expression of TFL, a LEAFY-Like Gene in Branched Spike Wheat (Triticum aestivum)

2017 ◽  
Vol 9 (2) ◽  
pp. 27
Author(s):  
Wang Yue ◽  
Sun Fulai ◽  
Gao Qingrong ◽  
Zhang Yanxia ◽  
Wang Nan ◽  
...  
Keyword(s):  
Photosynthetic Pigment ◽  
Dry Mass ◽  
Dichlorophenoxyacetic Acid ◽  
Naphthaleneacetic Acid ◽  
Branched Spike ◽  
Spike Development ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
The Impact ◽  
Indole 3 Acetic Acid ◽  
Putative Homologue

Branched spike wheat is a hexaploid germplasm with branched rachis on its main rachises, and the crucial period for branched rachises occurrence and development is just after the two ridges stage of shoot apex. Natural [indole-3-acetic acid (IAA), indole-3butyric acid (IBA)] and synthetic [(1-naphthaleneacetic acid (NAA), 2,4-Dichlorophenoxyacetic acid (2,4-D)] auxins were applied at this period to investigate the spike traits, seedling growth and photosynthesis related characters and expression of a putative homologue of the LEAFY in branched spike wheat. The four types of experienced auxins induced similar effects on these foresaid characters, although the impact extents were different among the auxins treatments. More branched rachis, spikelets, fertile florets and longer branched rachis were obtained in plants with IAA and IBA at 0.1 mM or NAA and 2,4-D at 1.0mM than those plants with no auxin treated. Auxin treatments also increased fresh and dry mass, photosynthetic pigment and parameters. TFL, a LEAFY-like gene was cloned in branched spike wheat and TFL mRNA expression was quantified using real-time reverse transcriptase-PCR. Application of the auxins accelerated the rise in TFL expression during the periods of branched rachises occurrence and extension. The data supports the hypothesis that auxins play a central role in the regulation branched spike development and TFL might correlate with the development of branched rachises in branched spike wheat.

Dynamique de la végétation d'emprises de lignes de transport d'énergie

1984 ◽  
Vol 62 (8) ◽  
pp. 1730-1738
Author(s):  
M. Darveau ◽  
P. Bellefleur
Keyword(s):  
Woody Species ◽  
Power Line ◽  
Power Lines ◽  
Underlying Structure ◽  
Dichlorophenoxyacetic Acid ◽  
Border Line ◽  
Control Power ◽  
Composition And Structure ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
The Impact

We made a preliminary study of the impact of phytocides on plant dynamics in the corridors of Hydro-Québec power lines. Three hypotheses were tested: the first assumed that the phytocides changed vegetation composition and structure in the corridors; the second assumed that the corridor under the power line favored the development of an ecotone at its border with the forest; the third assumed that the method used for initial cutting of the corridors (bulldozer or chain saw) affected the forthcoming vegetation for over 15 years. Vegetation was sampled on one control power line and four power lines maintained with mixtures of picloram, 2,4-dichlorophenoxyacetic acid, 2,4,5-trichlorophenoxyacetic acid, and sodium trichloroacetate. Multidimensional statistical analysis was used to show the underlying structure of the raw data and to test the hypotheses. We found out that phytocides are very efficient on woody species to the advantage of herbs, mostly grass, which invaded the corridors and created rather stable artificial communities. No significant ecotone was found at the border line of the corridors and the forest. The influence of the method for initial cutting of the corridors, although severe the first few years, disappeared after about 10 years under the action of the phytocides.

scholarly journals Differential regulation of GS-GOGAT gene expression by plant growth regulators in Arabidopsis seedlings

2016 ◽  
Vol 68 (2) ◽  
pp. 399-404 ◽  
Author(s):  
Milan Dragicevic ◽  
Ana Simonovic ◽  
Milica Bogdanovic ◽  
Angelina Subotic ◽  
Nabil Ghalawenji ◽  
...  
Keyword(s):  
Plant Growth ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Expression Patterns ◽  
Nuclear Gene ◽  
Glutamate Synthase ◽  
Ammonium Assimilation ◽  
Dichlorophenoxyacetic Acid ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
The Impact

Primary and secondary ammonium assimilation is catalyzed by the glutamine synthetase-glutamate synthase (GS-GOGAT) pathway in plants. The Arabidopsis genome contains five cytosolic GS1 genes (GLN1;1 - GLN1;5), one nuclear gene for chloroplastic GS2 isoform (GLN2), two Fd-GOGAT genes (GLU1 and GLU2) and a GLT1 gene coding for NADH-GOGAT. Even though the regulation of GS and GOGAT isoforms has been extensively studied in response to various environmental and metabolic cues in many plant species, little is known about the effects of phytohormones on their regulation. The objective of this study was to investigate the impact of representative plant growth regulators, kinetin (KIN), abscisic acid (ABA), gibberellic acid (GA3) and 2,4-dichlorophenoxyacetic acid (2,4-D), on the expression of A. thaliana GS and GOGAT genes. The obtained results indicate that GS and GOGAT genes are differentially regulated by growth regulators in shoots and roots. KIN and 2,4-D repressed GS and GOGAT expression in roots, with little effect on transcript levels in shoots. KIN affected all tested genes; 2,4-D was apparently more selective and less potent. ABA induced the expression of GLN1;1 and GLU2 in whole seedlings, while GA3 enhanced the expression of all tested genes in shoots, except GLU2. The observed expression patterns are discussed in relation to physiological roles of investigated plant growth regulators and N-assimilating enzymes.

scholarly journals Tolerance of Pseudomonas Strain to the 2,4-D Herbicide through a Peroxidase System

2021 ◽  
Author(s):  
Elizangela Paz Oliveira ◽  
Amanda Flávia da Silva Rovida ◽  
Juliane Gabriele Martins ◽  
Sônia Alvim Veiga Pileggi ◽  
Zelinda Schemczssen-Graeff ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Bacterial Communities ◽  
Defense Mechanism ◽  
Agricultural Practices ◽  
Dichlorophenoxyacetic Acid ◽  
Guaiacol Peroxidase ◽  
Pseudomonas Sp ◽  
Nontarget Organisms ◽  
Response System ◽  
2,4 Dichlorophenoxyacetic Acid

Herbicides are widely used in agricultural practices for preventing the proliferation of weeds that compete with crops for survival. Upon reaching soil and water, herbicides can damage nontarget organisms, such as bacteria, which need an efficient defense mechanism to tolerate the stress induced by herbicides. 2,4-Dichlorophenoxyacetic acid (2,4-D) is a herbicide that exerts increased oxidative stress among bacterial communities that consequently witness an increased toxicity in their microenvironments. Bacterial isolates were obtained from the biofilm of water that was contaminated with 2,4-D. This biofilm originated from the tanks containing washing water from the packaging of different pesticides, including 2,4-D. Moreover, several isolates were sensitive to biofilm toxicity; however, they remained alive in the presence of 2,4-D. The Pseudomonas sp. CMA-7.3 was selected because of its tolerance against biofilm agrochemicals. Therefore, the objective of this study is to evaluate the antioxidative response system of the Pseudomonas sp. CMA-7.3. This study also analyzed poorly evaluated enzymes, such as superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and guaiacol peroxidase GPX, in the bacterial systems. The toxic effects of 2,4-D on bacteria were evaluated using mechanisms indicating oxidative stress, such as growth curve, cell viability, peroxide, and malondialdehyde. The Pseudomonas sp. CMA-7.3 was an efficient response system against the activity of antioxidant enzymes such as SOD, CAT, APX, and GPX in balancing the production of H 2 O 2 , even at high doses as 25x the field dose of the herbicide, thereby proving the toxicity of 2,4-D for this strain and showing the ability of the strain to tolerate 2,4-D. The adaptation of this microorganism to herbicide exposure is truly relevant for improving future metabolic studies on bacterial communities. The strain showed a great potential in the application and developmental prospects of a new product in the bioremediation process of environments contaminated by these herbicides.

Effects of 2,4-D, maleic acid hydrazide, and 2,4,5-T on survival and growth of the prairie grain wireworm, Ctenicera destructor Brown (Coleoptera: Elateridae)

1968 ◽  
Vol 46 (4) ◽  
pp. 747-750 ◽  
Author(s):  
G. R. F. Davis
Keyword(s):  
Relative Humidity ◽  
Maleic Acid ◽  
Acid Hydrazide ◽  
Agricultural Practices ◽  
Dichlorophenoxyacetic Acid ◽  
Initial Weight ◽  
Survival And Growth ◽  
Trichlorophenoxyacetic Acid ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
Ctenicera Destructor

Larvae of Ctenicera destructor Brown having an average initial weight of 47.3 mg were reared individually for 6 months at 68 ± 2 °F and 75 ± 5% relative humidity, with diets containing 2,4-dichlorophenoxyacetic acid (2,4-D), maleic acid hydrazide (MH), or 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), at six concentrations. Although certain trends relating gains in weight of larvae to dietary concentrations of chemicals were observed, under normal agricultural practices these chemicals probably have little effect on field populations of the prairie grain wireworm.

Magnesium supplementation ameliorates toxic effects of 2,4-dichlorophenoxyacetic acid in rat model

2019 ◽  
Vol 39 (1) ◽  
pp. 47-58 ◽  
Author(s):  
S Shafeeq ◽  
T Mahboob
Keyword(s):  
Body Weight ◽  
Rat Model ◽  
Control Group ◽  
Dichlorophenoxyacetic Acid ◽  
Experimental Conditions ◽  
Nitrogen Levels ◽  
Oxidative Damages ◽  
Male Wistar Rats ◽  
Group 2 ◽  
2,4 Dichlorophenoxyacetic Acid

2,4-Dichlorophenoxyacetic acid (2,4-D) is an extensively used herbicide in the field of agriculture, its ever-escalating use induces toxicity, health effects, and environmental impact. Oxidative stress plays a key role in pathogenesis of 2,4-D-induced liver and kidney damage. Magnesium (Mg) is a highly effective antioxidant agent in restoring oxidative damage by directly influencing the metabolic and physiological processes. Therefore, the present study aimed to evaluate Mg role in ameliorating the oxidative damages provoked by 2,4-D in rat model. Male Wistar rats (180–220 g) were distributed into four groups and treated intragastrically for 4 weeks. Group 1: control, group 2: 2,4-D (150 mg/kg body weight/day), group 3: simultaneously treated with 2,4-D (150 mg/kg body weight/day) and Mg supplement (50 mg/kg body weight/day), and group 4: Mg supplement (50 mg/kg body weight/day). Under experimental conditions, plasma hepatic and renal biomarkers, tissue oxidative status, and antioxidant enzymes activities were investigated. Results demonstrated that 2,4-D intoxication caused hepatic and renal impairments as indicated by the significantly increased ( p < 0.001) alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, urea, creatinine, and blood urea nitrogen levels. In addition, 2,4-D caused a significant enhancement ( p < 0.001) in the level of malondialdehyde as well as reduction ( p < 0.001) of the superoxide dismutase, catalase, and glutathione reductase activities in both hepatic and renal tissues. Mg treatment prevented and reversed the toxic variations induced by 2,4-D. In general, these outcomes suggest that Mg may have antioxidant potential and ameliorative effects against 2,4-D provoking hepatic and renal toxicity in rat model.

scholarly journals Comparison of 2,4-Dichlorophenoxyacetic Acid Degradation and Plasmid Transfer in Soil Resulting from Bioaugmentation with Two Different pJP4 Donors

2000 ◽  
Vol 66 (8) ◽  
pp. 3399-3407 ◽  
Author(s):  
D. T. Newby ◽  
T. J. Gentry ◽  
I. L. Pepper
Keyword(s):  
Ralstonia Eutropha ◽  
Plasmid Transfer ◽  
Indigenous Populations ◽  
Dichlorophenoxyacetic Acid ◽  
Soil System ◽  
E Coli ◽  
Indigenous Plasmid ◽  
Key Factor ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
The Impact

ABSTRACT A pilot field study was conducted to assess the impact of bioaugmentation with two plasmid pJP4-bearing microorganisms: the natural host, Ralstonia eutropha JMP134, and a laboratory-generated strain amenable to donor counterselection,Escherichia coli D11. The R. eutropha strain contained chromosomal genes necessary for mineralization of 2,4-dichlorophenoxyacetic acid (2,4-D), while the E. colistrain did not. The soil system was contaminated with 2,4-D alone or was cocontaminated with 2,4-D and Cd. Plasmid transfer to indigenous populations, plasmid persistence in soil, and degradation of 2,4-D were monitored over a 63-day period in the bioreactors. To assess the impact of contaminant reexposure, aliquots of bioreactor soil were reamended with additional 2,4-D. Both introduced donors remained culturable and transferred plasmid pJP4 to indigenous recipients, although to different extents. Isolated transconjugants were members of theBurkholderia and Ralstonia genera, suggesting multiple, if not successive, plasmid transfers. Upon a second exposure to 2,4-D, enhanced degradation was observed for all treatments, suggesting microbial adaptation to 2,4-D. Upon reexposure, degradation was most rapid for the E. coli D11-inoculated treatments. Cd did not significantly impact 2,4-D degradation or transconjugant formation. This study demonstrated that the choice of donor microorganism might be a key factor to consider for bioaugmentation efforts. In addition, the establishment of an array of stable indigenous plasmid hosts at sites with potential for reexposure or long-term contamination may be particularly useful.

scholarly journals Chlorophyll a Fluorescence Parameters do not Detect Yield-limiting Injury from Sub-lethal Rates of 2,4-Dichlorophenoxyacetic Acid (2,4-D) in Cotton (Gossypium hirsutum)

2020 ◽  
pp. 34-48
Author(s):  
Seth A. Byrd ◽  
John L. Snider ◽  
Timothy L. Grey ◽  
A. Stanley Culpepper ◽  
Jared R. Whitaker ◽  
...  
Keyword(s):  
Chlorophyll A ◽  
Chlorophyll A Fluorescence ◽  
Yield Loss ◽  
Block Design ◽  
Dichlorophenoxyacetic Acid ◽  
Growth Stages ◽  
Biologically Relevant ◽  
Fluorescence Parameters ◽  
Significant Difference ◽  
2,4 Dichlorophenoxyacetic Acid

Aims: Determine if the use of novel chlorophyll a fluorescence parameters could be utilized to predict yield loss of cotton exposed to sublethal rates of 2,4-dichlorophenoxyacetic acid (2,4-D) at various growth stages. Study Design: All trials were arranged in a randomized complete block design with four replications. Treatment means were subjected to analysis of variance and linear regression was utilized to determine relationship between chlorophyll a parameters and yield. Place and Duration of Study: University of Georgia Gibbs Farm in Tifton, GA, USA and the Sunbelt Agricultural Exposition in Moultrie, GA, USA during the 2013 growing season. Methodology: Two sublethal rates of 2,4-D were applied to cotton at six distinct growth stages. The rates consisted of 2 g and 40 g ae ha-1 equivalent to 1/421 and 1/21 of the full rate (0.532 kg ae ha-1), respectively. The sublethal rates were applied to cotton at six growth stages, including the four leaf, nine leaf, first bloom, two, four and six weeks after first bloom growth stages. A fluorometer was used to obtain the fluorescence parameters Fv/Fm, ΦEO and PIABS from the uppermost fully expanded leaves at various intervals after 2,4-D exposure. Results: Despite yield losses ranging from 20 – 90% of the non-treated control, no consistent patterns resulted from utilizing fluorescence transients to detect 2,4-D injury and overall instances of significant difference were minimal and typically not biologically relevant. In many cases, treatments exposed to 2,4-D that exhibited yield loss showed evidence of greater photosynthetic efficiency than the non-treated control. In the majority of instances, many of fluorescence parameters measured fell within ranges observed in previous studies in cotton produced under typical or non-stressed conditions. Conclusion: While it has been proven as a valuable tool in other plant screening endeavors, chlorophyll a fluorescence were not able to detect the effects of sub-lethal rates of 2,4-D on cotton, even in instances that resulted in severe yield loss.

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