Pesticides are chemical substances intended for preventing or controlling pests. These are toxic substances which contaminate soil, water bodies and vegetative crops. Excessive use of pesticides may ...cause destruction of biodiversity. In plants, pesticides lead to oxidative stress, inhibition of physiological and biochemical pathways, induce toxicity, impede photosynthesis and negatively affect yield of crops. Increased production of reactive oxygen species like superoxide radicals, O
−
2
hydrogen peroxide, H
2
O
2
; singlet oxygen, O
2
; hydroxyl radical, OH
−
; and hydroperoxyl radical HO
2−
, causes damage to protein, lipid, carbohydrate and DNA within plants. Plant growth regulators (PGR) are recognized for promoting growth and development under optimal as well as stress conditions. PGR combat adverse effect by acting as chemical messenger and under complex regulation, enable plants to survive under stress conditions. PGR mediate various physiological and biochemical responses, thereby reducing pesticide-induced toxicity. Exogenous applications of PGRs, such as brassinosteroid, cytokinins, salicylic acid, jasmonic acid, etc., mitigate pesticide toxicity by stimulating antioxidant defense system and render tolerance towards stress conditions. They provide resistance against pesticides by controlling production of reactive oxygen species, nutrient homeostasis, increase secondary metabolite production, and trigger antioxidant mechanisms. These phytohormones protect plants against oxidative damage by activating mitogen-stimulated protein kinase cascade. Current study is based on reported research work that has shown the effect of PGR in promoting plant growth subjected to pesticide stress. The present review covers the aspects of pesticidal response of plants and evaluates the contribution of PGRs in mitigating pesticide-induced stress and increasing the tolerance of plants. Further, the study suggests the use of PGRs as a tool in mitigating effects of pesticidal stress together with improved growth and development.
Apoptosis is the elimination of functionally non-essential, neoplastic, and infected cells via the mitochondrial pathway or death receptor pathway. The process of apoptosis is highly regulated ...through membrane channels and apoptogenic proteins. Apoptosis maintains cellular balance within the human body through cell cycle progression. Loss of apoptosis control prolongs cancer cell survival and allows the accumulation of mutations that can promote angiogenesis, promote cell proliferation, disrupt differentiation, and increase invasiveness during tumor progression. The apoptotic pathway has been extensively studied as a potential drug target in cancer treatment. However, the off-target activities of drugs and negative implications have been a matter of concern over the years. Phytochemicals (PCs) have been studied for their efficacy in various cancer cell lines individually and synergistically. The development of nanoparticles (NPs) through green synthesis has added a new dimension to the advancement of plant-based nanomaterials for effective cancer treatment. This review provides a detailed insight into the fundamental molecular pathways of programmed cell death and highlights the role of PCs along with the existing drugs and plant-based NPs in treating cancer by targeting its programmed cell death (PCD) network.
Purpose: Heavy metal stress due to the application of sewage water is considered a leading factor for constrained plant growth. Therefore, Current study was performed in the field to investigate the ...interactive influence of two irrigation sources (canal and sewage) and exogenous application of brassinosteroid (BRs) and silicon (Si) at different rates on growth, photosynthetic and physiological attributes of three leafy vegetables (lettuce, cabbage, and spinach). Methods: Three treatments were applied such as control, BRs and Si with three replications under split plot factorial design. Results: The results indicated that all the growth parameters including fresh biomass of plants and roots, dry biomass of plant and root, leaf area (LA), photosynthetic traits, chlorophyll contents, water use efficiency (WUE), activity of antioxidant enzymes; superoxide dismutase (SOD), peroxidase (POD), Catalase (CAT), ascorbate peroxidase (APX) and uptake of silicon except Cd and Pb contents were improved significantly with the foliar spray of BRs and Si over control treatment under both types of irrigation sources. However maximum improvement in leafy vegetables was recorded when the foliar spray of BRs and Si were applied under canal water irrigation. Conclusions: The foliar application of BRs and Si was proved as an ameliorating strategy for improving tolerance mechanisms associated with heavy metal stress. The major restoring mechanism was the restricted translocation of Cd and Pb leading to better growth and physiology under sewage water. Thus the application of BRs and Si reduced the detrimental effect of Cd and Pb led to improve the growth and physiological traits of leafy vegetables under irrigation with sewage water.
Thiamethoxam, a broad spectrum, neonicotinoid insecticide, is used on various crops including Brassica juncea L. to protect from intruding insects such as leaf-hoppers, aphids, thrips and ...white-flies. Exposure to thiamethoxam causes acute malady such as tumour development, cell apoptosis, liver damage and neurotoxicity. Melatonin is entailed in umpteen developmental processes of plants, including stress responses. The pleiotropic effects of melatonin in modulating plant growth validate it’s imperative contribution as multi-regulatory substance. Exiguous information is known about the role of Pseudomonas putida in improving plant growth under thiamethoxam stress. Taking these aspects into consideration the contemporary study investigates the role of melatonin and Pseudomonas putida strain MTCC 3315 in alleviating the thiamethoxam induced toxicity in B. juncea plant. Fourier Transform Infrared Spectroscopy (FTIR) analysis uncloaked that thiamethoxam induced stress primarily affects the protein content of plant as compared to lipids, carbohydrates and cell wall components. Organic acid profiling of the treated samples carried-out by High-Performance Liquid Chromatography (HPLC), reported an upregulation in the level of organic acids, malic acid (110%), citric acid (170%), succinic acid (81%), fumaric acid (40%) and ascorbic acid (55%) in thiamethoxam treated plants compared to the investigational untreated plants. The melatonin treated seedlings grown under thiamethoxam stress, exhibit increased level of malic acid, citric acid, succinic acid, fumaric acid and ascorbic acid by 81%, 0.94%, 11%, 21% and 6% respectively. Further, thiamethoxam stressed plants inoculated with Pseudomonas putida showed stupendous up-regulation by 161% (malic acid), by 14% (citric acid), by 33% (succinic acid), by 30% (fumaric acid), by 100% (oxalic acid) respectively. Lastly, the combinatorial application of melatonin and Pseudomonas putida resulted in prodigious upsurge of malic acid by 165%, succinic acid by 69%, fumaric acid by 42% respectively in contrast to distinct melatonin and Pseudomonas putida treatments. The accumulation of organic acids ascertains the defence against thiamethoxam stress and corresponds to meet the energy generation requirement to skirmish thiamethoxam mediated abiotic stress in Brassica juncea plant.
Amplified concentrations of lead (Pb) in cultivable soils, being a major environmental concern, bring about malicious consequences for plant and human health. Trigonella foenum-graecum (fenugreek) is ...a multipurpose herb used as a spice, tonic, leafy vegetable, and therapeutic agent. Earlier works have revealed the inhibitory effects of Pb toxicity in Trigonella, affecting its growth and productivity. Therefore, the current experimental work was planned with the purpose of evaluating the effects of exogenously supplemented silicon (Si; 2 mM) and 24-epibrassinolide (24-EBL; 10−7 M) (in both individual and combined form) on growth attributes, osmolytes, metabolite measures, and antioxidant defense mechanisms of Trigonella foenum-graecum plants in response to three discrete concentrations of Pb stress (0.5, 0.7, and 0.9 mM). The results revealed that Pb stress affected morphological parameters of fenugreek plants via the genesis of reactive oxygen species (ROS), as indicated by higher measures of oxidative damage indicators like malondialdehyde (MDA) and hydrogen peroxide (H2O2). Spraying foliage with Si together with a pretreatment of 24-EBL alone as well as in a combined form yielded better outcomes in terms of growth parameters in the Pb-stressed plants. Pb toxicity decreased osmolytes, proteins, and metabolites. Components of the antioxidative defense system, i.e., enzymes ascorbate peroxidase (APX), guaiacol peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT), together with non-enzymes ascorbic acid (AsA) and glutathione (GSH), were downregulated when subjected to Pb toxicity. Out of all, Pb III (0.9 mM) had a more adverse impact on various parameters in fenugreek compared to Pb I (0.5 mM) and Pb II (0.7 mM). However, external supplementation with Si and 24-EBL (individually and in combination) ameliorated the Pb-mediated oxidative stress in fenugreek plants by improving the content of different osmolytes and metabolites while upregulating the functioning of the antioxidative defense system. Downregulation in the expression of SOD and CAT genes was found in Pb-stressed plants, while their expression was upregulated by Si and 24-EBL both individually and in combination. The experimental study revealed that the combined application of Si and 24-EBL was significantly better at abating the Pb metal stress in fenugreek plants when compared with their individual applications.
Citrus rinds contain essential oils. One of the major constituents of the essential oils in the zest of different fruits like Citrus sinensis, C. limon, and Vitis vinifera is limonene. In this ...research, limonene was extracted by hydro-distillation method using Clevenger set up and its antimicrobial activity against certain bacterial and fungal strains was determined by using Kirby Bauer’s disc diffusion method. The primary antimicrobial screening of limonene without dilution exhibited a zone of inhibition (mm) comparable to Ampicillin (20mg/ml) and Amphotericin B (20mg/ml). The effect of pure limonene against all strains used was high as compared to the isolated samples. The MIC values also showed an expected decrease in the zone of inhibition from 1:2 to 1:8 dilutions. Based on this study, the cost-effective isolation of limonene and other essential oils is quite possible.
The application of an electric field on a multi-component leaky dielectric fluid system leads to an electric stress at the fluid–fluid interface. To capture the effect of these electric stresses, we ...report a new method to couple the electrostatics and hydrodynamics of leaky dielectric fluids within the framework of the lattice Boltzmann method. The developed methodology relies on obtaining time invariant solution to the equation governing the divergence of current density in the flow domain using a time marching lattice Boltzmann equation or through a finite-difference formulation. The coupling between the low spurious velocity hydrodynamics model and the leaky dielectric counterpart is also illustrated through the use of three case studies involving interaction of single or multiple droplets suspended in an outer fluid under the action of an external electric field. The results obtained from the developed methodology are shown to be in excellent agreement with earlier published analytical and numerical results. Further, the numerical experiments demonstrate that the developed methodology is applicable for both steady- and time-dependent flows.
Phytoremediation is a technique for reducing or stabilizing hazardous chemicals in polluted soil or ground water. There is a loss of agricultural products and a degradation in food quality as a ...result of abiotic stresses, such as those generated by heavy metals and pesticides that have an effect on plants. These toxic compounds are extensively employed in agriculture, and they have a significant influence on both human health and agricultural output. The accumulation of these toxic, persistent, and poorly biodegradable compounds causes soil and ecological disparities. PGRs, or plant growth regulators, are an appealing possibility for increasing the efficacy of phytoremediation. Plant growth-promoting rhizobacteria (PGPR), a ubiquitous root microbiome, is widely used as a biocontrol agent. They have the ability to improve plant growth by colonizing plant roots, which can benefit the plant. Several PGPRs, including
P. aeruginosa
,
B.gladioli
, and
P.pseudoalcali,
have been shown to be resistant to biotic and abiotic stressors. Because of their ability to digest xenobiotic chemicals, plant growth-promoting rhizobacteria (PGPR) are a promising candidate for use in the phytoremediation process. Microorganisms inhabiting the rhizosphere participate in plant resistance mechanisms by secreting and generating a variety of important compounds such as siderophores, phytohormones, and metal-binding proteins. Rhizobacteria play an important role in phytoremediation of pesticide- and heavy metal-polluted soil by decomposing toxicants and promoting plant development via mechanisms such as chelation, acidification, and phosphate solubilization. Plant growth regulators (PGRs) increase plant biomass while reducing the negative impacts of contaminants and boosting growth in harsh settings. The use of certain PGRs as exogenous treatments have also been investigated as a potential way to improving crop stress tolerance; however the efficiency varies depending on the specific stress and plant type. Several plant growth regulators, such as brassinosteroids, melatonin, strigolactones, and others, have been proven to be useful in overcoming abiotic stress. The current review focuses on the utilization of PGRs and PGPRs in phytoremediation of heavy metal and pesticide-polluted soils.
PDF
