Mitigation of salt stress in Indian mustard (Brassica juncea L.) by the application of triacontanol and hydrogen sulfide.

Salinity stress is a well-known abiotic stress that has been shown to have a negative impact on crop growth, production, and soil richness. The current study was intended to ameliorate salt stress in Indian mustard (Brassica juncea L.), keeping in mind the detrimental influence of salt stress. A pot experimentation was executed on B. juncea to examine the efficacy of exogenous application of triacontanol (TRIA) and hydrogen sulfide (H2S) (NaHS donor), either alone or in combination, on growth attributes, metabolites, and antioxidant defense system exposed to salt stress at three distinct concentrations (50, 100 and 150 mM NaCl). Increase in the concentration of oxidative markers (malondialdehyde and hydrogen peroxide) was found which results in inhibited growth of B. juncea. The growth characteristics of plant, such as root and shoot length, fresh and dry weight under salt stress, were improved by foliar application of TRIA (150 µM) and H2S (25 µM) alone as well as in combination. Additionally, salt stress reduced the levels of protein, metabolites (flavonoids, phenolic and anthocyanin), antioxidant enzyme activity including that of ascorbate peroxidase, catalase, polyphenol oxidase and guaiacol peroxidase as well as the level of ascorbic acid and glutathione (non-enzymatic antioxidants). However, application of TRIA and H2S alone or in grouping substantially raised the content of protein, metabolites and antioxidant defense system in plants of B. juncea.

Persistence and remote sensing of agri-food wastes in the environment: Current state and perspectives.

Food demand is expected to increase globally by 60-110% from 2005 to 2050 due to diet shifts and population growth. This growth in food demand leads to the generation of enormous agri-food wastes (AFWs), which could be classified into pre-consumption and post-consumption. The AFW represents economic losses for all stakeholders along food supply chains, including consumers. It is reported that the direct financial, social, and environmental costs of food waste are 1, 0.9, and 0.7 trillion USD/year, respectively. Diverse conventional AFW management approaches are employed at the different life cycle levels (entre supply chain). The review indicates that inadequate transportation, erroneous packaging, improper storage, losses during processing, contamination, issues with handling, and expiry dates are the main reason for the generation of AFWs in the supply chain. Further, various variables such as cultural, societal, personal, and behavioral factors contribute to the AFW generation. The selection of a specific valorization technology is based on multiple physicochemical and biological parameters. Furthermore, other factors like heterogeneity of the AFWs, preferable energy carriers, by-products management, cost, end-usage applications, and environmental legislative and disposal processes also play a crucial role in adopting suitable technology. Valorization of AFW could significantly impact both economy and the environment. AFWs have been widely investigated for the development of engineered added-value biomaterials and renewable energy production. Considering this, this study has been carried out to highlight the significance of AFW cost, aggregation, quantification, and membrane-based strategies for its management. The study also explored the satellite remote sensing data for Spatio-temporal monitoring, mapping, optimization, and management of AFW management. Along with this, the study also explained the most recent strategies for AFW valorization and outlined the detailed policy recommendation along with opportunities and challenges. The review suggested that AFW should be managed using a triple-bottom-line strategy (economic, social, and environmental sustainability).

Heavy metal induced regulation of plant biology: Recent insights.

The presence of different forms of heavy metals in the earth crust is very primitive and probably associated with the origin of plant life. However, since the beginning of human civilisation, heavy metal use and its contamination to all living systems on earth have significantly increased due to human anthropogenic activities. Heavy metals are nonbiodegradable, which directly or indirectly impact photosynthesis, antioxidant system, mineral nutrition status, phytohormones and amino acid-derived molecules. Due to the toxic behaviour of some heavy metals, the endogenous status of chemical messengers like phytohormones may get significantly influenced, leading to harmful impacts on plant growth, development and overall yield of the plants. It has been noticed that exogenous application of phytohormones, that is, abscisic acid, salicylic acid, auxins, brassinosteroids, cytokinins, ethylene and gibberellins can positively regulate the heavy metal toxicity in plants through the regulation of the ascorbate-glutathione cycle, nitrogen metabolism, proline metabolisms, transpiration rate, and cell division. Furthermore, it may also restrict the entry of heavy metals into the plant cells, which aids in the recovery of plant growth and productivity. Besides these, some defence molecules also assist the plant in dealing with heavy metal toxicity. Therefore, the present review aims to bridge the knowledge gap in this context and present outstanding discoveries related to plant life supportive processes during stressful conditions including phytohormones and heavy metal crosstalk along with suggestions for future research in this field.

Application of melatonin and PGPR alleviates thiamethoxam induced toxicity by regulating the TCA cycle in Brassica juncea L.

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.

Nitrates in the environment: A critical review of their distribution, sensing techniques, ecological effects and remediation.

Nitrate pollution is eminent in almost all the developing nations as a result of increased natural activities apart from anthropogenic pollution. The release of nitrates in more than critical quantities into the water bodies causes accretion impacts on living creatures, environmental receptors, and human vigour by accumulation through the food chain. Nitrates have recently acquired researchers' huge attention and extend their roots in environmental contamination of surface and groundwater systems. The presence of nitrate in high concentrations in surface and groundwater triggers several health problems, for instance, methemoglobinemia, diabetes, eruption of infectious disorders, harmfully influence aquatic organisms. Sensing nitrate is an alternate option for monitoring the distribution of nitrate in different water bodies. Here we review electrochemical, spectroscopic, and electrical modes of nitrate sensing. It is concluded that, among the various sensors discussed in this review, FET sensors are the most desirable choice. Their sensitivity, ease of use and scope for miniaturisation are exceptional. Advanced functional materials need to be designed to satiate the growing need for environmental monitoring. Different sources of nitrate contamination in ground and surface water can be estimated using different techniques such as nitrate isotopic composition, co contaminants, water tracers, and other specialized techniques. This review intends to explore the research work on remediation of nitrate from wastewater and soil using different processes such as reverse osmosis, chemical denitrification, biological denitrification, ion exchange, electrodialysis, and adsorption. Denitrification proves as a promising alternative over previously reported techniques in terms of their nitrate removal because of its high cost-effectiveness.

Wonder or evil?: Multifaceted health hazards and health benefits of Cannabis sativa and its phytochemicals.

Cannabis sativa, widely known as 'Marijuana' poses a dilemma for being a blend of both good and bad medicinal effects. The historical use of Cannabis for both medicinal and recreational purposes suggests it to be a friendly plant. However, whether the misuse of Cannabis and the cannabinoids derived from it can hamper normal body physiology is a focus of ongoing research. On the one hand, there is enough evidence to suggest that misuse of marijuana can cause deleterious effects on various organs like the lungs, immune system, cardiovascular system, etc. and also influence fertility and cause teratogenic effects. However, on the other hand, marijuana has been found to offer a magical cure for anorexia, chronic pain, muscle spasticity, nausea, and disturbed sleep. Indeed, most recently, the United Nations has given its verdict in favour of Cannabis declaring it as a non-dangerous narcotic. This review provides insights into the various health effects of Cannabis and its specialized metabolites and indicates how wise steps can be taken to promote good use and prevent misuse of the metabolites derived from this plant.

Adsorption and detoxification of pharmaceutical compounds from wastewater using nanomaterials: A review on mechanism, kinetics, valorization and circular economy.

Antibiotics overuse, inappropriate conduct, and discharge have led to adverse effects on various ecosystems. The occurrence of antibiotics in surface and drinking water is a matter of global concern. It is responsible for multiple disorders, including disruption of endocrine hormones and high chronic toxicity. The hospitals, pharmaceutical industries, households, cattle farms, and aquaculture are the primary discharging sources of antibiotics into the environment. This review provides complete detail on applying different nanomaterials or nanoparticles for the efficient removal of antibiotics from the diverse ecosystem with a broader perspective. Efforts have been made to focus on the degradation pathways and mechanism of antibiotic degradation using nanomaterials. More light has been shed on applying nanostructures in photocatalysis, which would be an economical and efficient solution. The nanoscale material or nanoparticles have incredible potential for mineralizing pharmaceutical compounds in aqueous solutions at low cost, easy handling characteristics, and high efficacy. Furthermore, nanoparticles can absorb the pharmaceutical by-products and wastes at a minimum cost as they can be easily recycled. With the increasing number of research in this direction, the valorization of pharmaceutical wastes and by-products will continue to expand as we progress from old conventional approaches towards nanotechnology. The utilization of nanomaterials in pharmaceutical wastewater remediation is discussed with a major focus on valorization, energy generation, and minimization and its role in the circular economy creating sustainable development.

Fascinating regulatory mechanism of silicon for alleviating drought stress in plants.

Plants confront several environmental stresses that are crucial in defining plant productivity. Among these environmental stresses, drought stress is recognized as the foremost abiotic factor which affects the food security around the globe due to its negative impact on the plant development, and quality of plant products. Because of this, drought stress has gained an imperative appearance in the field of plant sciences in recent years. Silicon (Si), an agronomically essential mineral nutrient, is recognized highly advantageous in enhancing plant growth at various phases of plant life cycle under water deficit circumstances. Si has been considered extensively useful in mitigating harmful consequences of drought stress by enhancing root H2O absorption, regulating uptake of nutrients, reducing transpiration rate, improving photosynthetic activity, increment in the production of compatible solutes and by elevating plant antioxidant defense functioning. Si also known to improve plant endurance to limited water availability by inducing the functioning of various stress associated genes. To maximize the potential benefits and sustainable efficiency of Si in agriculture, it is of crucial importance to gain knowledge about the underlying mechanisms of how Si counteract stress conditions. Various findings suggested that Si increases the plant's immune system against drought stress, and application of Si is an important approach to shield plants from adverse stress conditions and soil nutrient depletion. This paper shows that Si has imperative and noteworthy impacts on improving plant tolerance to drought stress via maintaining cellular homeostasis. Present review mainly provides an insight into silicon role as beneficial element to alleviate drought stress in plants by regulating their morphological, physicochemical and molecular characteristics.

Dietary Polyunsaturated Fatty Acids (PUFAs): Uses and Potential Health Benefits.

PURPOSE OF REVIEW: Polyunsaturated fatty acids (PUFAs) are obtained from various sources, which can be incorporated in the routine diet to maintain the health. They provide protection from several diseases like osteoarthritis, cancer, and autoimmune disorders. Major focus is given to the PUFAs omega-3 (ω-3) and omega-6 (ω-6) fatty acids which are available in both terrestrial and in the marine environment. The main concern of this article is to review the key scientific reports in context with the human health consequences and advantages of the food sources of ω-3 and ω-6 fatty acids. RECENT FINDINGS: ω-3 and ω-6 fatty acids are consumed by the population globally in the form of foods that are rich in fatty acids. Their nutritional effects have the capability to improve the physical functioning and metabolic rate of the body. These PUFAs contribute in various cellular activities like cell signaling, structural integrity and fluidity of cell membrane, the regulation of blood pressure, glucose level, the nervous system, inflammatory reactions, and hematic clotting. Animal and cell-based models represent that ω-3 and ω-6 PUFAs can regulate the skeletal muscle metabolism. The main concern of this article is to review the key scientific reports in context with the human health consequences and advantages of the food sources of ω-3 and ω-6 fatty acids.

Detection and disinfection of COVID-19 virus in wastewater.

The coronavirus disease 2019, COVID-19, caused by the severe acute respiratory syndrome coronavirus 2, SARS-CoV-2, appears as a major pandemic having adverse impact on public health and economic activities. Since viral replication in human enterocytes results in its faecal shedding, wastewater surveillance is an ideal, non-invasive, cost-effective and an early warning epidemiological approach to detect the genetic material of SARS-CoV-2. Here, we review techniques for the detection of SARS-CoV-2 in municipal wastewater, and disinfectants used to control viral spread. For detection, concentration of ribonucleic acid involves ultrafiltration, ultracentrifugation and polyethylene glycol precipitation. Identification is done by reverse transcriptase amplification, nucleic acid sequence-based amplification, helicase dependent amplification, loop-mediated isothermal amplification, recombinase polymerase amplification, high throughput screening and biosensor assays. Disinfectants include ultraviolet radiations, ozone, chlorine dioxide, hypochlorites and hydrogen peroxide. Wastewater surveillance data indicates viral presence within longer detection window, and provides transmission dynamics earlier than classical methods. This is particularly relevant for pre-symptomatic and asymptomatic COVID-19 cases.

Microbial biotechnological approaches: renewable bioprocessing for the future energy systems.

The accelerating energy demands of the increasing global population and industrialization has become a matter of great concern all over the globe. In the present scenario, the world is witnessing a considerably huge energy crisis owing to the limited availability of conventional energy resources and rapid depletion of non-renewable fossil fuels. Therefore, there is a dire need to explore the alternative renewable fuels that can fulfil the energy requirements of the growing population and overcome the intimidating environmental issues like greenhouse gas emissions, global warming, air pollution etc. The use of microorganisms such as bacteria has captured significant interest in the recent era for the conversion of the chemical energy reserved in organic compounds into electrical energy. The versatility of the microorganisms to generate renewable energy fuels from multifarious biological and biomass substrates can abate these ominous concerns to a great extent. For instance, most of the microorganisms can easily transform the carbohydrates into alcohol. Establishing the microbial fuel technology as an alternative source for the generation of renewable energy sources can be a state of art technology owing to its reliability, high efficiency, cleanliness and production of minimally toxic or inclusively non-toxic byproducts. This review paper aims to highlight the key points and techniques used for the employment of bacteria to generate, biofuels and bioenergy, and their foremost benefits.

Mechanisms of Plant Defense Under Pathogen Stress: A Review.

Being sessile organisms, plants are persistently confronted by a diverse array of biotic agents, including viruses, bacteria, fungi, herbivores, and nematodes. Understanding the mechanism of host-pathogen interactions is essential for improving plant resistance against these biotic factors. In this review, we have discussed various means and mechanisms by which pathogens influence the host plant defense. A virulent pathogen can reduce the growth and development of a plant, which eventually lowers its yield by multiple processes, like enhancement in cell death, as well as modification of plant architecture. This review also explains the various strategies used by plants to control pathogen-caused diseases. These mainly include either resistance or tolerance by activating cell signaling pathways, which further regulate the synthesis and accumulation of several cellular products, such as phytohormones, enzymes, proteins, and secondary metabolites. To minimize the influence of infection on their vigor, plants also exhibit immunity regardless of the amount of pathogen multiplication. The current review provides an important insight into the mechanisms of host-pathogen interaction, which is very significant for efficient disease management.

Physiological responses, tolerance, and remediation strategies in plants exposed to metalloids.

Metalloids are a subset of particular concern to risk assessors and toxicologists because of their well-documented potential hazards to plant system. Most of the metalloids are major environmental contaminants which affect crop productivity when present in high concentrations in soil. Metalloids are coupled with carrier proteins of the plasma membrane and translocated to various organs causing changes in key metabolic processes, damages cell biomolecules, and finally inhibit its growth. Phytoremediation-based approaches help in understanding the molecular and biochemical mechanisms for prerequisite recombinant genetic approaches. Recent advancements in proteomics and plant genomics help in understanding the role of transcription factors, metabolites, and genes in plant system which confers metal tolerance. The present review summarizes our current status of knowledge in this direction related to various physiological responses, detoxification mechanisms, and remediation strategies of metalloids in crop plants in relation to plant-metalloid tolerance. Further, the role of various transcription factors and miRNAs in conferring metal tolerance is also briefed. Hence, the present review mainly focused on the alterations in the physiological activities of plants due to metalloid toxicity and the various mechanisms which get activated inside the plants to mitigate their toxic effects.

Herbicide Glyphosate: Toxicity and Microbial Degradation.

Glyphosate is a non-specific organophosphate pesticide, which finds widespread application in shielding crops against the weeds. Its high solubility in hydrophilic solvents, especially water and high mobility allows the rapid leaching of the glyphosate into the soil leading to contamination of groundwater and accumulation into the plant tissues, therefore intricating the elimination of the herbicides. Despite the widespread application, only a few percentages of the total applied glyphosate serve the actual purpose, dispensing the rest in the environment, thus resulting in reduced crop yields, low quality agricultural products, deteriorating soil fertility, contributing to water pollution, and consequently threatening human and animal life. This review gives an insight into the toxicological effects of the herbicide glyphosate and current approaches to track and identify trace amounts of this agrochemical along with its biodegradability and possible remediating strategies. Efforts have also been made to summarize the biodegradation mechanisms and catabolic enzymes involved in glyphosate metabolism.

Plant growth regulators: a sustainable approach to combat pesticide toxicity.

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, H2O2; singlet oxygen, O2; hydroxyl radical, OH-; and hydroperoxyl radical HO2-, 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.

Trichoderma: The "Secrets" of a Multitalented Biocontrol Agent.

The plant-Trichoderma-pathogen triangle is a complicated web of numerous processes. Trichoderma spp. are avirulent opportunistic plant symbionts. In addition to being successful plant symbiotic organisms, Trichoderma spp. also behave as a low cost, effective and ecofriendly biocontrol agent. They can set themselves up in various patho-systems, have minimal impact on the soil equilibrium and do not impair useful organisms that contribute to the control of pathogens. This symbiotic association in plants leads to the acquisition of plant resistance to pathogens, improves developmental processes and yields and promotes absorption of nutrient and fertilizer use efficiency. Among other biocontrol mechanisms, antibiosis, competition and mycoparasitism are among the main features through which microorganisms, including Thrichoderma, react to the presence of other competitive pathogenic organisms, thereby preventing or obstructing their development. Stimulation of every process involves the biosynthesis of targeted metabolites like plant growth regulators, enzymes, siderophores, antibiotics, etc. This review summarizes the biological control activity exerted by Trichoderma spp. and sheds light on the recent progress in pinpointing the ecological significance of Trichoderma at the biochemical and molecular level in the rhizosphere as well as the benefits of symbiosis to the plant host in terms of physiological and biochemical mechanisms. From an applicative point of view, the evidence provided herein strongly supports the possibility to use Trichoderma as a safe, ecofriendly and effective biocontrol agent for different crop species.

Chromium Bioaccumulation and Its Impacts on Plants: An Overview.

Chromium (Cr) is an element naturally occurring in rocky soils and volcanic dust. It has been classified as a carcinogen agent according to the International Agency for Research on Cancer. Therefore, this metal needs an accurate understanding and thorough investigation in soil-plant systems. Due to its high solubility, Cr (VI) is regarded as a hazardous ion, which contaminates groundwater and can be transferred through the food chain. Cr also negatively impacts the growth of plants by impairing their essential metabolic processes. The toxic effects of Cr are correlated with the generation of reactive oxygen species (ROS), which cause oxidative stress in plants. The current review summarizes the understanding of Cr toxicity in plants via discussing the possible mechanisms involved in its uptake, translocation and sub-cellular distribution, along with its interference with the other plant metabolic processes such as chlorophyll biosynthesis, photosynthesis and plant defensive system.

Revealing on hydrogen sulfide and nitric oxide signals co-ordination for plant growth under stress conditions.

In the recent times, plants are facing certain types of environmental stresses, which give rise to formation of reactive oxygen species (ROS) such as hydroxyl radicals, hydrogen peroxides, superoxide anions and so on. These are required by the plants at low concentrations for signal transduction and at high concentrations, they repress plant root growth. Apart from the ROS activities, hydrogen sulfide (H2 S) and nitric oxide (NO) have major contributions in regulating growth and developmental processes in plants, as they also play key roles as signaling molecules and act as chief plant immune defense mechanisms against various biotic as well as abiotic stresses. H2 S and NO are the two pivotal gaseous messengers involved in growth, germination and improved tolerance in plants under stressed and non-stress conditions. H2 S and NO mediate cell signaling in plants as a response to several abiotic stresses like temperature, heavy metal exposure, water and salinity. They alter gene expression levels to induce the synthesis of antioxidant enzymes, osmolytes and also trigger their interactions with each other. However, research has been limited to only cross adaptations and signal transductions. Understanding the change and mechanism of H2 S and NO mediated cell signaling will broaden our knowledge on the various biochemical changes that occur in plant cells related to different stresses. A clear understanding of these molecules in various environmental stresses would help to confer biotechnological applications to protect plants against abiotic stresses and to improve crop productivity.

Exploiting the Allelopathic Potential of Aqueous Leaf Extracts of Artemisia absinthium and Psidium guajava against Parthenium hysterophorus, a Widespread Weed in India.

Artemisia absinthium and Psidium guajava are powerful sources of secondary metabolites, some of them with potential allelopathic activity. Both the species grow together in India with a weed (Parthenium hysterophorus) that is becoming extremely invasive. The aim of the present research was to test the allelopathic effect of A. absinthium and P. guajava aqueous leaf extracts on seed germination, seedling growth (shoot and root length), as well as some biochemical parameters (enzymatic and non-enzymatic antioxidants, photosynthetic pigments, osmolytes, and malondialdehyde by-products) of P. hysterophorus plants. Leaf extracts of both A. absinthium and P. guajava constrained the germination and seedling development (root and shoot length), affected pigment content (chlorophylls, carotenoids), stimulated the activity of antioxidant enzymes, and increased the level of malondialdehyde by-products of P. hysterophorus plants. Non-enzymatic antioxidants (glutathione and ascorbic acid) in P. hysterophorus leaves were, conversely, negatively affected by both leaf extracts tested in the present experiment. Although A. absinthium was more effective than P. guajava in impacting some biochemical parameters of P. hysterophorus leaves (including a higher EC50 for seed germination), P. guajava extract showed a higher EC50 in terms of root inhibition of P. hysterophorus seedlings. The present study provides the evidence that A. absinthium and P. guajava extract could be proficiently exploited as a botanical herbicide against P. hysterophorus.

Modulation of the Functional Components of Growth, Photosynthesis, and Anti-Oxidant Stress Markers in Cadmium Exposed Brassica juncea L.

Abstract: Heavy metals (including Cadmium) are being entered into the environment through various sources and cause toxicity to plants. Response of Brassica juncea L. var. RLC-1 was evaluated after exposing them to different concentration of cadmium (Cd) for seven days. Seeds of B. juncea were treated with different concentrations of Cd like 0.2-0.6 mM for 7 days, allowing them to grow in Petri-dishes, and seedlings were examined for different physiological responses. Following exposure to Cd, in the seedlings of B. juncea, growth parameters (root and shoot length), stress markers (lipid peroxidation and H2O2 content), secondary metabolites, photosynthetic pigments, and ion analysis, were estimated along with enzymatic and non-enzymatic antioxidants. We observed a significant reduction in root and shoot length after Cd treatment as compared to control seedlings. Malondialdehyde and H2O2 contents were increased accompanied by enhanced Cd uptake. Activities of antioxidative enzymes were also significantly altered following Cd exposure to the seedlings of B. juncea. Conclusively, we suggest that Cd exposure to the seedlings triggered an induction of several defense responses in B. juncea including major metabolites.