Use of Parthenium hysterophorus with synthetic chelator for enhanced uptake of cadmium and lead from contaminated soils-a step toward better public health

Menadiol diacetate mediated subcellular Cd accumulation and nutrients uptake alleviates Cd toxicity and increases growth and yield of summer squash

Cadmium (Cd) has shown toxicity to reduce growth and productivity in different plants. The Present study investigated the efficacy of menadiol diacetate (MD) to reduce Cd stress on growth and yield of summer squash plants. The experiment was performed under saturated Hoagland's nutrient solution (control) while the other group was supplemented with 0.1 mM CdCl2 (Cd stress). Surface sterilized seeds of summer squash were primed in different concentrations (10, 20 µM) of MD as well as in distilled water for 24 h and sown in the pots. Different morphological and physio-biochemical attributes were determined after 35 d of growth whereas the data for yield attributes was collected after 70 d. Cd concentration was determined in various subcellular compartments i.e., cell walls and cell wall debris, chloroplast, cell membrane and other organelles including vacuoles. The Cd stress decreased photosynthetic pigments, osmoprotectants and ultimately caused reduction in the yield attributes. Further, it increased the secondary metabolites and oxidants (MDA and H2O2) in the summer squash tissues. Cd exposure also altered ions accumulation in the summer squash tissues by increasing the root and shoot Ca2+ (24-93%) and Fe (4-18%) ions while decreasing the Mg2+ (31-39%) ions. The MD-priming, particularly at 10 µM concentration mediated increase in the total phenolics, ascorbic acid, and anthocyanins concentration, and thus enhanced growth and yield attributes of summer squash exposed to Cd toxicity. Further, 10 µM MD-priming facilitated Cd compartmentalization in the subcellular compartments mainly in the cell wall (58%) rather than in the chloroplast (18%), cell membrane (7%) and soluble fractions (18%). In this context, cell wall and vacuole were the key compartments for Cd sequestration. This study highlights MD-priming as a potential strategy to counter Cd toxicity in summer squash plants.

Elucidating the phytoremediation potentials and ecophysiological mechanisms of indicator plants in the industrial polluted region

The integrity of natural ecosystems, particularly in the Global South, is increasingly compromised by industrial contaminants. Our study examines the growth of plant species adapted to ecosystems impacted by heavy metal pollution, specifically focusing on their phytoremediation capabilities and tolerance to contaminants. The potential of pollution-tolerant species was evaluated in the industrial subtropical wetland of Sialkot, Pakistan. Employing quantitative ecological methods, data on vegetation, phytosociological attributes, and soil properties were gathered from 450 plots across different pollution gradients. The study pinpointed 17 key indicator species tolerating high heavy metal pollution out of 182 surveyed, using a combination of Indicator Species Analysis (ISA) and the Importance Value Index (IVI). These species demonstrated diverse capacities to extract, stabilize, and accumulate heavy metals (Cr, Zn, Cu, As, Cd, Ni, Hg, and Pb) across varying pollution zones. Notably, Cannabis sativa demonstrated substantial phytoextraction of Zn and Cd, with concentrations reaching 1977.25 μg/g and 1362.78 μg/g, respectively. Arundo donax showed marked hyperaccumulation of Cd, peaking at 410.531 μg/g. Achyranthes aspera was remarkable for its extraction and accumulation of Ni and Cu, with concentrations of 242.412 μg/g and 77.2997 μg/g, respectively. Physiological changes, such as increased proline levels in Cannabis sativa and Achyranthes aspera reaching 39.041 μg/g and 27.523 μg/g under high metal concentrations, indicated adaptation to metal stress. Declines in chlorophyll and carotenoid levels were also observed as metal contamination increased, with up to 35% reductions in some species. These findings underscore the potential efficacy of selected plant species in phytoremediation and highlight the importance of physiological responses in their tolerance to metals, providing valuable information for targeted remediation strategies in polluted ecosystems and improving environmental management and sustainable practices.

Comparative assessment of pantothenic, aspartic, ascorbic and tartaric acids assisted Pb-phytoextraction by sunflower (Helianthus annuus L.)

Phytoextraction of lead (Pb) is a challenging task due to its extremely low mobility within soil and plant systems. In this study, we tested the influence of some novel chelating agents for Pb-phytoextraction using sunflower. The Pb was applied at control (0.0278 mM) and 4.826 mM Pb as Pb(NO3)2 through soil-spiking. After 10 days of Pb addition, four different organic ligands (aspartic, ascorbic, tartaric, and pantothenic acids) were added to the soil at 1 mM concentration each. respectively. In the absence of any chelate, sunflower plants grown at 4.826 mM Pb level accumulated Pb concentrations up to 104 µg g-1 DW in roots, whereas 64 µg g-1 DW in shoot. By contrast, tartaric acid promoted significantly Pb accumulation in roots (191 µg g-1 DW; + 45.5%) and shoot (131.6 µg g-1 DW; + 51.3%). Pantothenic acid also resulted in a significant Pb-uptake in the sunflower shoots (123 µg g-1 DW; + 47.9%) and in roots (177.3 µg g-1 DW; + 41.3%). The least effective amongst the chelates tested was aspartic acid, but it still contributed to + 40.1% more Pb accumulation in the sunflower root and shoots. In addition, plant growth, biochemical, and ionomic parameters were positively regulated by the organic chelates used. Especially, an increase in leaf Ca, P, and S was evident in Pb-stressed plants in response to chelates. These results highlight that the use of biocompatible organic chelates positively alters plant physio-biochemical traits contributing to higher Pb-sequestration in sunflower plant parts.

Anhydroparthenin as a dual-target inhibitor against Sterol C-24 methyltransferase and Sterol 14-α demethylase of Leishmania donovani: A comprehensive in vitro and in silico study

Parthenium hysterophorus plant has a diverse chemical profile and immense bioactive potential. It exhibits excellent pharmacological properties such as anti-cancer, anti-inflammatory, anti-malarial, microbicidal, and anti-trypanosomal. The present study aims to evaluate the anti-leishmanial potential and toxicological safety of anhydroparthenin isolated from P. hysterophorus. Anydroparthenin was extracted from the leaves of P. hysterophorus and characterized through detailed analysis of 1H, 13C NMR, and HRMS. Dye-based in vitro and ex vivo assays confirmed that anhydroparthenin significantly inhibited both promastigote and amastigote forms of the Leishmania donovani parasites. Both the cytotoxicity experiment and hemolytic assay revealed its non-toxic nature and safety index in the range of 10 to 15. Further, various mechanistic assays suggested that anhydroparthenin led to the generation of oxidative stress, intracellular ATP depletion, alterations in morphology and mitochondrial membrane potential, formation of intracellular lipid bodies, and acidic vesicles, ultimately leading to parasite death. As a dual targeting approach, computational studies and sterol quantification assays confirmed that anhydroparthenin inhibits the Sterol C-24 methyl transferase and Sterol 14-α demethylase proteins involved in the ergosterol biosynthesis in Leishmania parasites. These results suggest that anhydroparthenin could be a promising anti-leishmanial molecule and can be developed as a novel therapeutic stratagem against leishmaniasis.

Detoxifying the heavy metals: a multipronged study of tolerance strategies against heavy metals toxicity in plants

Heavy metal concentrations exceeding permissible limits threaten human life, plant life, and all other life forms. Different natural and anthropogenic activities emit toxic heavy metals in the soil, air, and water. Plants consume toxic heavy metals from their roots and foliar part inside the plant. Heavy metals may interfere with various aspects of the plants, such as biochemistry, bio-molecules, and physiological processes, which usually translate into morphological and anatomical changes. They use various strategies to deal with the toxic effects of heavy metal contamination. Some of these strategies include restricting heavy metals to the cell wall, vascular sequestration, and synthesis of various biochemical compounds, such as phyto-chelators and organic acids, to bind the free moving heavy metal ions so that the toxic effects are minimized. This review focuses on several aspects of genetics, molecular, and cell signaling levels, which integrate to produce a coordinated response to heavy metal toxicity and interpret the exact strategies behind the tolerance of heavy metals stress. It is suggested that various aspects of some model plant species must be thoroughly studied to comprehend the approaches of heavy metal tolerance to put that knowledge into practical use.

Carbon sequestration potential of different forest types in Pakistan and its role in regulating services for public health

A high amount of CO2 causes numerous health effects, including headaches, restlessness, difficulty in breathing, increased heart rate, high blood pressure, asphyxia, and dizziness. This issue of increasing atmospheric CO2 can only be solved via above-ground and below-ground carbon sequestration (CS). This study was designed to determine the relationship between CS with the crown area (CA), diameter at breast height (DBH), height (H), species richness (SR), and elevation in different forest types of Pakistan with the following specific objectives: (1) to quantify the direct and indirect relationship of carbon sequestration with CA, DBH, H, and SR in various natural forest types and (2) to evaluate the effect of elevation on the trees functional traits and resultant CS. We used the linear structural equation model (SEM) for each conceptual model. Our results confirmed that the highest CS potential was recorded for dry temperate conifer forests (DTCF) i.e., 52.67%, followed by moist temperate mix forests (MTMF) and sub-tropical broad-leaved forests (STBLF). The SEM further described the carbon sequestration variation, i.e., 57, 32, 19, and 16% under the influence of CA (β = 0.90 and P-value < 0.001), H (β = 0.13 and p-value = 0.05), DBH (β = 0.07 and p-value = 0.005), and SR (β = -0.55 and p-value = 0.001), respectively. The individual direct effect of SR on carbon sequestration has been negative and significant. At the same time, the separate effect of CA, DBH, and H had a positive and significant effect on carbon sequestration. The remaining 20% of CS variations are indirectly influenced by elevation. This means that elevation affects carbon sequestration indirectly through CA, DBH, H, and SR, i.e., β = 0.133 and P-value < 0.166, followed by β = 0.531 and P-value < 0.001, β = 0.007 and P-value < 0.399, and β = -0.32 and P-value < 0.001, respectively. It is concluded that abiotic factors mainly determined carbon sequestration in forest ecosystems along with the elevation gradients in Pakistan. Quantifying the role of various forest types in carbon dioxide (CO2) reduction leads to improved air quality, which positively impacts human health. This is an imperative and novel study that links the dynamics of the biosphere and atmosphere.