Insights into the growth and biochemical defense responses associated with fenitrothion toxicity and uptake by freshwater cyanobacteria

The extensive use of fenitrothion (FNT) in agricultural practices induces its persistence in soil and waterways. Therefore, it is essential to implement effective management practices such as using cyanobacteria for FNT removal and accumulation, particularly under accidental contamination. To this end, we evaluated the responses of two freshwater cyanobacteria taxa, Nostoc muscorum and Anabaena laxa to mild (7.5 mg L-1) and high (15 mg L-1) levels of FNT over a period of 7 d. Compared to N. muscorum, A. laxa was more tolerant to FNT, exhibiting higher FNT uptake and removal efficiencies at mild (16.3%) and high (17.5%) levels. FNT induced a dose-dependent decrease in cell growth, Chl a, phosphoenolpyruvate carboxylase and ribulose-1,5-bisphosphate carboxylase/oxygenase activities, which were more pronounced in N. muscorum. Moreover, FNT significantly increased oxidative damage markers i.e., increased lipid peroxidation (MDA), protein oxidation, H2O2 levels and NADPH oxidase enzyme activity, to more extent in N. muscorum. Compared to N. muscorum, A. laxa had high antioxidant capacity (FRAP), glutathione and increased activities of glutathione-S-transferase, glutathione reductase, glutathione peroxidase and superoxide dismutase, suggesting a robust antioxidant defense mechanism to mitigate FNT toxicity. However, N. muscorum devoted the induction of ascorbate content and the activity of catalase, peroxidase, monodehydroascorbate reductase, ascorbate peroxidase, and dehydroascorbate reductase enzymes. Although A. laxa had greater intracellular FNT, it experienced less FNT-induced oxidative stress, likely due to over production of antioxidants. Consequently, A. laxa is considered as a promising candidate for FNT phycoremediation. Our findings provide fundamental information on species-specific toxicity of FNT among cyanobacteria and the environmental risk of FNT toxicity in aquatic environments.

Climate and soil factors co-derive the functional traits variations in naturalized downy thorn apple (Datura innoxia Mill.) along the altitudinal gradient in the semi-arid environment

Plant functional traits are consistently linked with certain ecological factors (i.e., abiotic and biotic), determining which components of a plant species pool are assembled into local communities. In this sense, non-native naturalized plants show more plasticity of morphological traits by adopting new habitat (an ecological niche) of the invaded habitats. This study focuses on the biomass allocation pattern and consistent traits-environment linkages of a naturalized Datura innoxia plant population along the elevation gradient in NW, Pakistan. We sampled 120 plots of the downy thorn apple distributed in 12 vegetation stands with 18 morphological and functional biomass traits during the flowering season and were analyzed along the three elevation zones having altitude ranges from 634.85 m to 1405.3 m from sear level designated as Group I to III identified by Ward's agglomerative clustering strategy (WACS). Our results show that many morphological traits and biomass allocation in different parts varied significantly (p < 0.05) in the pair-wise comparisons along the elevation. Likewise, all plant traits decreased from lower (drought stress) to high elevation zones (moist zones), suggesting progressive adaptation of Datura innoxia with the natural vegetation in NW Pakistan. Similarly, the soil variable also corresponds with the trait's variation e.g., significant variations (P < 0.05) of soil organic matter, organic carbon, Nitrogen and Phosphorus was recorded. The trait-environment linkages were exposed by redundancy analysis (RDA) that was co-drive by topographic (elevation, r = -0.4897), edaphic (sand, r = -0.4565 and silt, r = 0.5855) and climatic factors. Nevertheless, the influences of climatic factors were stronger than soil variables that were strongly linked with elevation gradient. The study concludes that D. innoxia has adopted the prevailing environmental and climatic conditions, and further investigation is required to evaluate the effects of these factors on their phytochemical and medicinal value.

Correction: Biogenic synthesis of silver nanoparticles using Rubus fruticosus extract and their antibacterial efficacy against Erwinia caratovora and Ralstonia solanacearum phytopathogens

[This corrects the article DOI: 10.1039/D3RA06723H.].

Rapid alkalinization factor 22 has a structural and signalling role in root hair cell wall assembly

Pressurized cells with strong walls make up the hydrostatic skeleton of plants. Assembly and expansion of such stressed walls depend on a family of secreted RAPID ALKALINIZATION FACTOR (RALF) peptides, which bind both a membrane receptor complex and wall-localized LEUCINE-RICH REPEAT EXTENSIN (LRXs) in a mutually exclusive way. Here we show that, in root hairs, the RALF22 peptide has a dual structural and signalling role in cell expansion. Together with LRX1, it directs the compaction of charged pectin polymers at the root hair tip into periodic circumferential rings. Free RALF22 induces the formation of a complex with LORELEI-LIKE-GPI-ANCHORED PROTEIN 1 and FERONIA, triggering adaptive cellular responses. These findings show how a peptide simultaneously functions as a structural component organizing cell wall architecture and as a feedback signalling molecule that regulates this process depending on its interaction partners. This mechanism may also underlie wall assembly and expansion in other plant cell types.

Ecological factors affecting minerals and nutritional quality of "Dryopteris filix-mas (L.) Schott": an underutilized wild leafy vegetable in rural communities

Dryopteris filix-mas (hereafter D. filix-mas), a wild leafy vegetable, has gained popularity among high mountain residents in the Hindukush-Himalaya region due to its exceptional nutritional profile, and their commercial cultivation also offers viable income alternatives. Nevertheless, besides phytochemicals with medicinal applications, ecological factors strongly affect their mineral contents and nutritional composition. Despite this, little has been known about how this wild fern, growing in heterogeneous ecological habitats with varying soil physiochemical properties and coexisting species, produces fronds with optimal mineral and nutritional properties. Given its nutritional and commercial significance, we investigated how geospatial, topographic, soil physiochemical characteristics and coexisting plants influence this widely consumed fern's mineral and nutrient content. We collected soil, unripe fern fronds, and associated vegetation from 27 D. filix-mas populations in Swat, NW Pakistan, and were analyzed conjointly with cluster analysis and ordination. We found that the fronds from sandy-loam soils at middle elevation zones exhibited higher nitrogen contents (9.17%), followed by crude fibers (8.62%) and fats (8.09%). In contrast, juvenile fronds from the lower and high elevation zones had lower moisture (1.26%) and ash (1.59%) contents, along with fewer micronutrients such as calcium (0.14-0.16%), magnesium (0.18-0.21%), potassium (0.72-0.81%), and zinc (12% mg/kg). Our findings indicated the fern preference for middle elevation zones with high organic matter and acidic to neutral soil (pH ≥ 6.99) for retaining higher nutritional contents. Key environmental factors emerged from RDA analysis, including elevation (r = -0.42), aspect (r = 0.52), P-3 (r = 0.38), K+ (r = 0.41), EC (r = 0.42), available water (r = -0.42), and field capacity (r = -0.36), significantly impacting fern frond's mineral accumulation and nutrient quality enhancement. Furthermore, coexisting plant species (r = 0.36) alongside D. filix-mas played a pivotal role in improving its mineral and nutritional quality. These findings shed light on the nutritional potential of D. filix-mas, which could help address malnutrition amidst future scarcity induced by changing climates. However, the prevalent environmental factors highlighted must be considered if the goal is to cultivate this fern on marginal lands for commercial exploitation with high mineral and nutrient yields in Hindukush-Himalaya.

Malate production, sugar metabolism, and redox homeostasis in the leaf growth zone of Rye (Secale cereale) increase stress tolerance to aluminum stress: A biochemical and genome-wide transcriptional study

Global soil acidification is increasing, enlarging aluminum (Al) availability in soils, leading to reductions in plant growth. This study investigates the effect of Al stress on the leaf growth zones of Rye (Secale cereale, cv Beira). Kinematic analysis showed that the effect of Al on leaf growth rates was mainly due to a reduced cell production rate in the meristem. Transcriptomic analysis identified 2272 significantly (log2fold > |0.5| FDR < 0.05) differentially expressed genes (DEGs) for Al stress. There was a downregulation in several DEGs associated with photosynthetic processes and an upregulation in genes for heat/light response, and H2O2 production in all leaf zones. DEGs associated with heavy metals and malate transport were increased, particularly, in the meristem. To determine the putative function of these processes in Al tolerance, we performed biochemical analyses comparing the tolerant Beira with an Al sensitive variant RioDeva. Beira showed improved sugar metabolism and redox homeostasis, specifically in the meristem compared to RioDeva. Similarly, a significant increase in malate and citrate production, which are known to aid in Al detoxification in plants, was found in Beira. This suggests that Al tolerance in Rye is linked to its ability for Al exclusion from the leaf meristem.

Biogenic synthesis of silver nanoparticles using Rubus fruticosus extract and their antibacterial efficacy against Erwinia caratovora and Ralstonia solanacearum phytopathogens

In the current research, we produced green, cost-effective, eco-friendly silver nanoparticles using a single-step approach. Plants are considered highly desirable systems for nanoparticle synthesis because they possess a variety of secondary metabolites with significant reduction potential. In the current research, the dried leaf extract of Rubus fruticosus was utilized as a capping and reducing agent for the fabrication of silver nanoparticles, to prepare reliable biogenic silver nanoparticles and subsequently to investigate their potential against some common phytopathogens. The prepared silver nanoparticles were exploited to quantify the total flavonoid content (TFC), total phenolic content (TPC) and DPPH-based antioxidant activity. Different concentrations of aqueous extracts of plant leaves and silver nitrate (AgNO3) were reacted, and the color change of the reactant mixture confirmed the formation of Rubus fruticosus leaf-mediated silver nanoparticles (RFL-AgNPs). A series of characterization techniques such as UV-vis spectroscopy, transmission electron microscopy, energy dispersive X-ray analysis and X-ray diffraction revealed the successful synthesis of silver nanoparticles. The surface plasmon resonance peak appeared at 449 nm. XRD analysis demonstrated the crystalline nature, EDX confirmed the purity, and TEM demonstrated that the nanoparticles are mostly spherical in form. Furthermore, the biosynthesized nanoparticles were screened for in vitro antibacterial activity, antioxidant activity, and total phenolic and flavonoid content. The nanoparticles were used in different concentrations alone and in combination with plant extracts to inhibit Erwinia caratovora and Ralstonia solanacearum. In high-throughput assays used to inhibit these plant pathogens, the nanoparticles were highly toxic against bacterial pathogens. This study can be exploited for planta assays against phytopathogens utilizing the same formulations for nanoparticle synthesis and to develop potent antibacterial agents to combat plant diseases.

Biochar and saline soil: mitigation strategy by incapacitating the ecological threats to agricultural land

Soil salinity caused a widespread detrimental issue that hinders productivity in agriculture and ecological sustainability, while waste-derived soil amendments like biochar have drawn attention for their capacity to act as a mitigating agent, by enhancing the physical and chemical features of soil, and contributing to the recovery of agricultural waste resources. However, the information concerning biochar and salinity which affect the physicochemical characteristics of soils, crop physiology, and growth is limited. To investigate whether biochar mitigates the salinity stress on wheat crop seedlings, we grow them with salinity stress (120 mM), and biochar (20 tons ha-1), and its interactive effects. The soil properties of soil organic carbon (SOC), soil organic matter (SOM), dissolved organic carbon (DOC), and soil available phosphorus (SAP) decreased in the saline soil by 36.71%, 46.97%, 26.31%, and 15.00%, while biochar treatment increased SOC, DOC, and SAP contents by 7.42%, 31.57%, and 15.00%, respectively. On the other hand, dissolved organic nitrogen (DON) contents decreased in all the treatments compared to the control. The root growth traits, SPAD values, leaf nitrogen, photosynthetic parameters, antioxidant enzymes, and reactive oxygen species decreased in the saline treatment while increasing in the biochar and interactive treatment. Thus, these activities resulted in higher leaves and root biomass in the biochar treatment alone and interactive treatment of salinity and biochar. According to principal component analysis, redundancy analysis, and the mantel test, using biochar in conjunction with salinity treatment was found to be more effective than salinity treatment alone. The results of this study suggest that biochar can be used as a sustainable agricultural technique and a means of mitigation agent by lowering soil salinity while increasing the biomass of crops.

Synergistic effect of nitrate exposure and heatwaves on the growth, and metabolic activity of microalgae, Chlamydomonas reinhardtii, and Pseudokirchneriella subcapitata

Aquatic biota are threatened by climate warming as well as other anthropogenic stressors such as eutrophication by phosphates and nitrate. However, it remains unclear how nitrate exposure can alter the resilience of microalgae to climate warming, particularly heatwaves. To get a better understanding of these processes, we investigated the effect of elevated temperature and nitrate pollution on growth, metabolites (sugar and protein), oxidative damage (lipid peroxidation), and antioxidant accumulation (polyphenols, proline) in Chlamydomonas reinhardtii and Pseudokirchneriella subcapitata. The experiment involved a 3 × 3 factorial design, where microalgae were exposed to one of three nitrate levels (5, 50, or 200 mg L-1 NO3-l) at 20 °C for 2 weeks. Subsequently, two heatwave scenarios were imposed: a short and moderate heatwave at 24 °C for 2 weeks, and a long and intense heatwave with an additional 2 weeks at 26 °C. A positive synergistic effect of heatwaves and nitrate on growth and metabolites was observed, but this also led to increased oxidative stress. In the short and moderate heatwave, oxidative damage was controlled by increased antioxidant levels. The high growth, metabolites, and antioxidants combined with low oxidative stress during the short and moderate heatwaves in moderate nitrate (50 mg L-1) led to a sustainable increased food availability to grazers. On the other hand, long and intense heatwaves in high nitrate conditions caused unsustainable growth due to increased oxidative stress and relatively low antioxidant (proline) levels, increasing the risk for massive algal die-offs.

The pleiotropic role of Salinicoccus bacteria in enhancing ROS homeostasis and detoxification metabolism in soybean and oat to cope with pollution of triclosan

Triclosan has been extensively used as a preservative in cosmetics and personal care products. However, its accumulation represents a real environmental threat. Thus, its phytotoxic impact needs more consideration. Our study was conducted to highlight the phytotoxic effect of triclosan on the growth, ROS homeostasis, and detoxification metabolism of two different plant species i.e., legumes (Glycine max) and grass (Avena sativa). Moreover, we investigated the potentiality of plant growth-promoting bacteria (ST-PGPB) in mitigating the phytotoxic effect of triclosan. Triclosan induced biomass (fresh and dry weights) reduction in both plants, but to a higher extent in oats. This decline was associated with a noticeable increment in the oxidative damage (e.g., MDA and H2O2) and detoxification metabolites such as metallothionein (MTC), phytochelatins (PCs), and glutathione-S-transferase (GST). This elevation was associated with a remarkable reduction in both enzymatic and non-enzymatic antioxidants. On the other hand, the bioactive strain of ST-PGPB, Salinicoccus sp. JzA1 significantly alleviated the harmful effect of triclosan on both soybean and oat plants by enhancing their biomass, photosynthesis, as well as levels of minerals (K, Ca, P, Mn, and Zn). In parallel, a striking quenching in oxidative damage and an obvious improvement in non-enzymatic (polyphenols, tocopherols, flavonoids) and enzymatic antioxidants were observed. Furthermore, Salinicoccus sp. JzA1 augmented the detoxification metabolism by enhancing the levels of phytochelatins, metallothionein, and glutathione-S-transferase (GST) activity in a species-specific manner which is more apparent in soybean rather than in oat plants. To this end, stress mitigating impact of Salinicoccus sp. JzA1 provides a basis to improve the resilience of crop species under cosmetics and personal care products toxicity.

Rapeseed plant: biostimulation effects of plant growth-promoting Actinobacteria on metabolites and antioxidant defense system under elevated CO2 conditions

BACKGROUND

The present study set out to evaluate the potential of plant growth-promoting Actinobacteria (PGPB) in improving some physiological and molecular parameters of rapeseed (Brassica napus L.) plants under ambient and elevated CO2 conditions by assessing some nitrogen- and sulfur-containing metabolites, antioxidant defense system and antimicrobial activity. With this aim, a pot experiment was conducted where the rapeseed plants were treated with Actinobacterium sp. strain NCO2 (OQ451136) and were grown under two levels of air CO2 concentrations: ambient CO2 (aCO2 , 410 μmol CO2  mol-1 ); and elevated CO2 (eCO2 , 710 μmol CO2  mol-1 ).

RESULTS

There was an increase in the photosynthetic pigments (+35-80%) and photosynthesis rate (+20-34%) in PGPB-treated plants under eCO2 compared to control plants, resulting in further growth and biomass production (+53-294%). These results were associated with an enhancement in the content of total antioxidant capacity (+15-128%), polyphenols (+21-126%) and α-tocopherols (+20-138%) under both eCO2 and PGPB application (in combination or individual application), while only the combined treatment (eCO2  + PGPB) led to a significantly higher accumulation of antioxidant enzymes (+88-197%), β-tocopherols (+177%) and flavonoids (+155%). Moreover, nitrogen- and sulfur-containing metabolites (glucosinolates and amino acids) were improved by PGPB treatment and/or CO2 levels, in which PGPB increased the amino acid-derived glucosinolate induction by eCO2 with low levels of effective sulforaphane.

CONCLUSIONS

Therefore, the interaction effects of beneficial Actinobacteria and eCO2 are expected to boost the level of antioxidant molecules and to have a helpful role in improving plant biomass and adaptability to complicated climate changes in the future. © 2023 Society of Chemical Industry.

Enhanced Cd phytoextraction by rapeseed under future climate as a consequence of higher sensitivity of HMA genes and better photosynthetic performance

This study aimed to investigate the underlying physiological, biochemical, and molecular mechanisms responsible for Brassica napu's potential to remediate Cd-contaminated soil under current (CC) vs. future (FC) climate (400 vs. 800 ppm of CO2, 21/14 °C vs. 25/18 °C). B. napus exhibited good tolerance to low Cd treatments (Cd-1, Cd-10, i.e., 1, 10 mg kg-1) under both climates without visible phytotoxicity symptoms. TI sharply decreased by 47 % and 68 % (p < 0.05), respectively, in Cd-50 and Cd-100 treated shoots under CC, but to a lesser extent (-26 % and -53 %, p < 0.05) under FC. This agreed with increased photosynthetic apparatus performance under FC, primarily due to a significant decrease in the closure of active PSII RCs ((dV/dt)o, TRo/RC) and less dissipated excitation energy (DIo/RC, φDo). Calvin Benson cycle-related enzyme activity also improved under FC with 2.2-fold and 2.4-fold (p < 0.05) increases in Rubisco and TPI under Cd-50 and Cd-100, respectively. Consequentially, a 2.2-fold and 2.3-fold (p < 0.05) boosted Pr resulted in a 2.3-fold and 2.4-fold (p < 0.05) increase in the DW of Cd-50 and Cd-100 treated shoots, respectively. This also led to a decrease (26 %, p < 0.05) in shoot Cd concentration under both high Cd treatments with a slight reduction in BCF. Translocation factor (TF) decreased (on average 42 %, p < 0.05) by high Cd treatments under both climates. However, under Cd-100, FC increased TF by 1.7-fold (p < 0.05) compared to CC, which could be explained by significant increases in the expression of HMA genes, especially BnaHMA4a and BnaHMA4c. Finally, Cd TU increased under FC by 65 % and 76 % (p < 0.05) under Cd-50 and Cd-100. This led to a shorter hypothetical remediation time for reaching the Cd pollution limit by 35 (p > 0.05) and 61 (p < 0.05) years, respectively, compared to CC.

Cellular dynamics in the maize leaf growth zone during recovery from chilling depends on the leaf developmental stage

KEY MESSAGE

A novel non-steady-state kinematic analysis shows differences in cell division and expansion determining a better recovery from a 3-day cold spell in emerged compared to non-emerged maize leaves. Zea mays is highly sensitive to chilling which frequently occurs during its seedling stage. Although the direct effect of chilling is well studied, the mechanisms determining the subsequent recovery are still unknown. Our goal is to determine the cellular basis of the leaf growth response to chilling and during recovery of leaves exposed before or after their emergence. We first studied the effect of a 3-day cold spell on leaf growth at the plant level. Then, we performed a kinematic analysis to analyse the dynamics of cell division and elongation during recovery of the 4th leaf after exposure to cold before or after emergence. Our results demonstrated cold more strongly reduced the final length of non-emerged than emerged leaves (- 13 vs. - 18%). This was not related to growth differences during cold, but a faster and more complete recovery of the growth of emerged leaves. This difference was due to a higher cell division rate on the 1st and a higher cell elongation rate on the 2nd day of recovery, respectively. The dynamics of cell division and expansion during recovery determines developmental stage-specific differences in cold tolerance of maize leaves.

Brassica oleracea L. (Acephala Group) based zinc oxide nanoparticles and their efficacy as antibacterial agent

Abstract Zinc oxide nanoparticles were synthesized from the leaf extract of Brassica oleracea L. Acephala group (collard green) followed by their characterization using Scanning Electron Microscope (SEM), and Energy Dispersive X-ray (EDX). The antibacterial properties of zinc nanoparticles were tested against Gram-negative bacteria, Pseudomonas aeruginosa (ATCC ® 9027™), Escherichia coli (ATCC ® 8739™), Klebsiella pneumoniae (ATCC® BAA-1705™) and Gram-positive bacteria, Staphylococcus aureus (ATCC ® 6538™) and Listeria monocytogenes (ATCC ® 13932™), at four different concentrations (50.00 µg/ml, 100.00 µg/ml, 500.00 µg/ml and 1 mg/ml) of zinc oxide nanoparticles suspension. Results revealed that the synthesized nanoparticles exhibit strong antibacterial effects against Pseudomonas aeruginosa, Listeria monocytogenes, Klebsiella pneumonia, Staphylococcus aureus and Escherichia coli at 500.00 µg/ml-1 mg/ml concentrations. An increase in efficacy of nanoparticles with the decrease of their size was also evident. This is a first ever report on Brassica oleracea, L. based nanoparticles which demonstrates that 500.00 µg-1 mg/ml conc. of zinc oxide nanoparticles have antibacterial activity against both Gram -ve and Gram +ve bacteria and have the potential to be considered as an antibacterial agent in future.

Protein extracted from Moringa oleifera Lam. Leaves: Bio-evaluation and characterization as suitable plant-based meat-protein alternative

This study aimed to isolate and characterize moringa leaf protein (MLP) via HPLC and evaluate its consumption's effects through rat model. Four groups of Albino Wistar rats (n = 25 each) along with a control group (n = 25) were acclimatized. The isolated MLP was added to the basal diet (casein; control) in various percentages (25, 50, 75, 100%) for a 21-day experimental period. On three intervals (1st, 11th, 21st days), blood samples were collected and subjected for hematological and biochemical examination (Renal Function Test (RFT), Liver Function Test (LFT)). MLP contained a variety of essential and non-essential amino acids in substantial amounts. The Protein Efficiency Ratio (PER) of 50% MLP-treated group was the highest (1.72) among MLP treatments. Increases in feed intake and weight were observed in treated rats compared to the control. The hematological profile of the rats revealed increases in Hemoglobin (Hb) (7.9-14.0%), White Blood Cell (WBC) (35.9-51.5%), Red Blood Cell (RBC) (17.1-22.2%), Hematocrit (HCT) (13.1-22.9%), and platelets levels (36.5-40.6%) from day 1. Protein isolates decreased liver parameters but resulted in non-significant changes in liver and kidney functions in rats. Further investigation is needed to determine the safe daily intake of MLP.

Tracing probiotic producing bacterial species from gut of buffalo (Bubalus bubalis), South-East-Asia

Abstract Due to extensive application of antibiotics as growth promoters in animal feed, antimicrobial resistance has been increased. To overcome this challenge, rumen microbiologists search for new probiotics to improve the rate of livestock production. The present study was aimed to isolate and evaluate breed-specific lactic acid bacteria (LAB) as potential animal probiotics. The current study was conducted during 10 months from July 2020 to April 2021, in which a total of n=12 strains were isolated from different samples including milk, rumen, and feces of Nilli Ravi Buffaloes. These isolates were evaluated for their antimicrobial potential against common animal pathogens (Bacillus spp., E. coli, Staphylococcus aureus, Salmonella spp., Listeria spp.). All the isolates were identified using 16S rRNA gene sequencing and the phylogenetic analyses inferred that these strains showed close relations to the species of various genera; Enterococcus lactis, Pediococcus pentosaceus, Bacillus subtilis Weissella cibaria, Weissella soli, Bacillus tequilensis, Weissella bombi, Bacillus licheniformis, Lactococcus lactis, Bacillus megaterium, Lactobacillus ruminis, and Lactococcus lactis. NMCC-Ru2 has exhibited the enormous potential of antimicrobial activity, 28 mm, for Salmonella typhimurium;23 mm for Listeria monocytogenes 21 mm for E.coil. Highest resistance was seen in NMCC-Ru2 agasint test antbiotic, like 25.5 mm for Tetracycline. Overall results revesl that the probiotic profile of isolates was achieved using standard criteria, particularly with animal probiotic properties

Response of nine triticale genotypes to different salt concentrations at the germination and early seedling stages

Salinity stress poses a major challenge to agricultural productivity worldwide, and understanding their responses at the early growth stage is vital for devising strategies to cope with this stress. Therefore, to improve triticale productivity, this study investigated the salinity stress tolerance of different salt-tolerant triticale genotypes aiming to cultivate them on saline soils. To this end, salinity stress impacts on nine triticale genotypes, i.e., Zhongsi 1084, Gannong No. 2, Gannong No. 4, Shida No. 1, C6, C16, C23, C25 and C36 at germination and early seedling stages was evaluated. Each genotype was subjected to six treatments inducing control, 40, 80, 120, 160, and 200 mM NaCl treatments to study their effect on seedling and termination traits of the nine genotypes. Compared to the overall mean seedling vigor index, the seedling vigor index was higher in the genotypes Zhongsi 1084 and C6 (39% and 18.1%, respectively) and lower in Gannong No.2 (41%). Increasing NaCl concentrations negatively affected germination and seedling traits. Compared to other genotypes, Zhongsi 1084 had the highest mean germination rate, germination vigor index, germination percentage, mean daily germination and germination energy. It also showed the lowest relative salt injury. The relative salt injury was higher in the genotype Shida No. 1 than those in Gannong No. 2, Gannong No. 4, Shida No. 1, C16, and C36 genotypes. All genotypes exhibited desirable mean germination time except for line C6. High significant positive correlations were observed among germination rate, germination vigor index, germination percentage, mean daily germination, seedling vigor index, and root length. Principal component analysis (PCA) grouped the most desirable genotypes into two clusters. Our study determined salt stress tolerance of nine triticale genotypes at germination and early seedling stages. to select salt-tolerant genotypes that can be cultivated on saline soil or after salt irrigation.

Biochemical and pharmaceutical traits of Marrubium vulgare L. plants treated with plant growth-promoting bacteria and elevated CO2

The present research aimed to understand the influence of plant growth-promoting bacteria (PGPB) on various biochemical, nutritional, and pharmaceutical characteristics of Marrubium vulgare plants grown under elevated carbon dioxide (eCO2). To achieve this objective, a pot experiment was carried out, consisting of two treatments, namely: (i) biofertilization (Bf) by a PGPB strain (Micromonospora sp.) and (ii) two different air CO2 levels, including ambient CO2 (aCO2) and eCO2 concentrations (410 and 710 μmol CO2 mol-1, respectively). The improvement in the photosynthesis rate of eCO2 and Bf-treated plants can explain the increase in the production of carbohydrate. This is evidenced by a substantial rise, reaching up to + 75% and 25% in the total sugar and starch content in plants subjected to eCO2 treatment, respectively. Additionally, eCO2-treated plants exhibited a remarkable 102% increase in soluble sugar synthesis, while plants subjected to Bf treatment showed a notable increase of 66%. Such modifications could be the main factor affecting plants carbon and nitrogen metabolism. Although the level of certain amino acids (such as glycine, tyrosine, and phenylalanine) in plants exhibited significant increases in response to eCO2 and Bf, the levels of other amino acids demonstrated enhancements in plants grown under eCO2 (e.g., histidine) or under treatments containing Bf (e.g., alanine and ornithine). Improvements in primary metabolites led to more benefits in plants treated with Bf and CO2 by boosting secondary metabolites accumulation, including phenolics (+ 27-100%), flavonoids (+ 30-92%), and essential oils (up to + 296%), as well as improved antioxidant capacity (FRAP). This remarkable effectiveness was evident in the significant increase in the biomass production, highlighting the synergistic impact of the treatments. Therefore, the interaction of Bf and eCO2 not only induced plant biomass accumulation but also improved the nutritional and pharmaceutical value of M. vulgare plants.

Chitosan nanoparticles upregulate C and N metabolism in soybean plants grown under elevated levels of atmospheric carbon dioxide

Despite the wide utilization of chitosan nanoparticles (CSNPs) as a promising approach for sustainable agriculture, their efficiency under elevated CO2 (eCO2), has not been evaluated. The interactive effects of CSNPs and eCO2 were evaluated on the growth and C and N metabolism of soybean plants. Plants were treated with CSNPs and grown under ambient CO2 (410 ppm, aCO2) or eCO2 (645 ppm). Regardless of CO2 level, CSNPs improved the net photosynthetic rate. CSNPs aggravated the effect of eCO2 treatment on the levels of non-structural carbohydrates (i.e., glucose, fructose, sucrose, and starch), especially in shoots, which was inconsistence with the upregulation of carbohydrates metabolizing enzymes. Being the most pivotal energetic and signaling organic compounds in higher plants, the synergistic action of CSNPs and eCO2 on the accumulation of soluble sugars upregulated the N metabolism as indicated by induced activities of nitrate reductase, arginase, glutamate dehydrogenase, glutamine synthetase, and glutamine oxoglutarate aminotransferase which was manifested finally as increased shoot and root total nitrogen content as well as proline and aspartate in roots. At the hormonal level, the coexistence of eCO2 with CSNPs further supports their positive impact on the contents of IAA and, to a lesser extent, GAs. The present data prove that the biofertilization capacity of CSNPs is even more potent under futuristic eCO2 levels and could even further improve the growth and resilience of plants.

Assessing lead and cadmium tolerance of Chenopodium ambrosioides during micropropagation: an in-depth qualitative and quantitative analysis

The tolerance of Chenopodium ambrosioides to some heavy metals under in vitro environment was thoroughly investigated. A micropropagation protocol was developed to facilitate the mass production of plants and to identify metals-tolerant species for potential use in the restoration of polluted areas. Nodal explants exhibited callus formation when treated with N6-benzyladenin (BA) (1.5 mg/l) and a combination of BA/α-naphthalene acetic acid (NAA) at concentrations of 1.5/1.0 mg/l on the Murashige and Skoog (MS) medium. The optimal shoot formation was achieved with the callus grown on a medium enriched with 1.5/1.0 mg/l BA/NAA, resulting in an impressive number (21.89) and length (11.79 cm) of shoots. The in vitro shoots were rooted using NAA (1.0 and 1.5 mg/l) and were acclimatized in pots with 71% survival rate. After standardizing micropropagation protocol, the in vitro shoots were subjected to various doses of lead nitrate (Pb(NO3)2 and cadmium chloride (CdCl2). Pb(NO3)2 and CdCl2 in the media let to a reduction in shoot multiplication, decreasing from 18.73 in the control group to 11.31 for Pb(NO3)2 and 13.89 for CdCl2 containing medium. However, Pb(NO3)2 and CdCl2 promoted shoot length from 5.61 in the control to 9.86 on Pb(NO3)2 and 12.51 on CdCl2 containing medium. In the case of Pb(NO3)2 treated shoots, the growth tolerance index (GTI) ranged from117.64% to 194.11%, whereas for CdCl2 treated shoots, the GTI ranged from 188.23% to 264.70%. Shoots treated with high level of Pb(NO3)2induced reddish-purple shoots, while a low level of Pb(NO3)2 induced shoots displayed both green and reddish-purple colors in the same explants. In CdCl2 treated culture, the toxic effects were narrow leaf lamina, elongated petiole and a dark reddish purple coloration. These findings highlight the remarkable potential of C. ambrosioides to maintain growth and organogenesis even in the presence Pb(NO3)2 and CdCl2 on the MS medium, indicating a high degree of metal tolerance.

Magnetic nanocomposite of maize offal biomass for effective sequestration of Congo red and methyl orange dyes from contaminated water: modeling, kinetics and reusability

The current study aims to use a facile and novel method to remove Congo red (CR) and Methyl Orange (MO) dyes from contaminated water with Maize offal biomass (MOB) and its nanocomposite with magnetic nanoparticles (MOB/MNPs). The MOB and MOB/MNPs were characterized with Fourier-transform infrared (FTIR), scanning electron microscopy (SEM), BET, XRD and point of zero charge (pHPZC). The influence of initial CR and MO levels (20-320 mg/L), adsorbent dosage (1-3 g/L), pH (3-9), co-exiting ions, temperature (25-45 °C) and time (15-180 min) was estimated. The findings demonstrated that MOB/MNPs exhibited excellent adsorption of 114.75 and 29.0 mg/g for CR and MO dyes, respectively while MOB exhibited 81.35 and 23.02 mg/g adsorption for CR and MO dyes, respectively at optimum pH-5, and dose 2 g/L. Initially, there was rapid dye removal which slowed down until equilibrium was reached. The interfering/competing ions in contaminated water and elevated temperature favored the dyes sequestration. The MOB/MNPs exhibited tremendous reusability and stability. The dyes adsorption was spontaneous, and exothermic with enhanced randomness. The adsorption effects were well explained with Freundlich model, pseudo second order and Elovich models. It is concluded that MOB/MNPs showed excellent, eco-friendly, and cost-effective potential to decontaminate the water.

Elevated CO2 Can Improve the Tolerance of Avena sativa to Cope with Zirconium Pollution by Enhancing ROS Homeostasis

Zirconium (Zr) is one of the toxic metals that are heavily incorporated into the ecosystem due to intensive human activities. Their accumulation in the ecosystem disrupts the food chain, causing undesired alterations. Despite Zr's phytotoxicity, its impact on plant growth and redox status remains unclear, particularly if combined with elevated CO2 (eCO2). Therefore, a greenhouse pot experiment was conducted to test the hypothesis that eCO2 can alleviate the phytotoxic impact of Zr upon oat (Avena sativa) plants by enhancing their growth and redox homeostasis. A complete randomized block experimental design (CRBD) was applied to test our hypothesis. Generally, contamination with Zr strikingly diminished the biomass and photosynthetic efficiency of oat plants. Accordingly, contamination with Zr triggered remarkable oxidative damage in oat plants, with concomitant alteration in the antioxidant defense system of oat plants. Contrarily, elevated levels of CO2 (eCO2) significantly mitigated the adverse effect of Zr upon both fresh and dry weights as well as the photosynthesis of oat plants. The improved photosynthesis consequently quenched the oxidative damage caused by Zr by reducing the levels of both H2O2 and MDA. Moreover, eCO2 augmented the total antioxidant capacity with the concomitant accumulation of molecular antioxidants (e.g., polyphenols, flavonoids). In addition, eCO2 not only improved the activities of antioxidant enzymes such as peroxidase (POX), superoxide dismutase (SOD) and catalase (CAT) but also boosted the ASC/GSH metabolic pool that plays a pivotal role in regulating redox homeostasis in plant cells. In this regard, our research offers a novel perspective by delving into the previously unexplored realm of the alleviative effects of eCO2. It sheds light on how eCO2 distinctively mitigates oxidative stress induced by Zr, achieving this by orchestrating adjustments to the redox balance within oat plants.

Biochemical composition changes can be linked to the tolerance of four grassland species under more persistent precipitation regimes

Climate models suggest that the persistence of summer precipitation regimes (PRs) is on the rise, characterized by both longer dry and longer wet durations. These PR changes may alter plant biochemical composition and thereby their economic and ecological characteristics. However, impacts of PR persistence have primarily been studied at the community level, largely ignoring the biochemistry of individual species. Here, we analyzed biochemical components of four grassland species with varying sensitivity to PR persistence (Holcus lanatus, Phleum pratense, Lychnis flos-cuculi, Plantago lanceolata) along a range of increasingly persistent PRs (longer consecutive dry and wet periods) in a mesocosm experiment. The more persistent PRs decreased nonstructural sugars, whereas they increased lignin in all species, possibly reducing plant quality. The most sensitive species Lychnis seemed less capable of altering its biochemical composition in response to altered PRs, which may partly explain its higher sensitivity. The more tolerant species may have a more robust and dynamic biochemical network, which buffers the effects of changes in individual biochemical components on biomass. We conclude that the biochemical composition changes are important determinants for plant performance under increasingly persistent precipitation regimes.

Yield, nutrition, and leaf gas exchange of lettuce plants in a hydroponic system in response to Bacillus subtilis inoculation

Inoculation with Bacillus subtilis is a promising approach to increase plant yield and nutrient acquisition. In this context, this study aimed to estimate the B. subtilis concentration that increases yield, gas exchange, and nutrition of lettuce plants in a hydroponic system. The research was carried out in a greenhouse in Ilha Solteira, Brazil. A randomized block design with five replications was adopted. The treatments consisted of B. subtilis concentrations in nutrient solution [0 mL "non-inoculated", 7.8 × 103, 15.6 × 103, 31.2 × 103, and 62.4 × 103 colony forming units (CFU) mL-1 of nutrient solution]. There was an increase of 20% and 19% in number of leaves and 22% and 25% in shoot fresh mass with B. subtilis concentrations of 15.6 × 103 and 31.2 × 103 CFU mL-1 as compared to the non-inoculated plants, respectively. Also, B. subtilis concentration at 31.2 × 103 CFU mL-1 increased net photosynthesis rate by 95%, intercellular CO2 concentration by 30%, and water use efficiency by 67% as compared to the non-inoculated treatments. The concentration of 7.8 × 103 CFU mL-1 improved shoot accumulation of Ca, Mg, and S by 109%, 74%, and 69%, when compared with non-inoculated plants, respectively. Inoculation with B. subtilis at 15.6 × 103 CFU mL-1 provided the highest fresh leaves yield while inoculation at 15.6 × 103 and 31.2 × 103 CFU mL-1 increased shoot fresh mass and number of leaves. Concentrations of 7.8 × 103 and 15.6 × 103 increased shoot K accumulation. The concentrations of 7.8 × 103, 15.6 × 103, and 31.2 × 103 CFU mL-1 increased shoot N accumulation in hydroponic lettuce plants.

Late autumn warming can both delay and advance spring budburst through contrasting effects on bud dormancy depth in Fagus sylvatica L

The current state of knowledge on bud dormancy is limited. However, expanding such knowledge is crucial in order to properly model forest responses and feedback to future climate. Recent studies have shown that warming can decrease chilling accumulation and increase dormancy depth, thereby inducing delayed budburst in European beech (Fagus sylvatica L). Whether fall warming can advance spring phenology is unclear. To investigate the effect of warming on endodormancy of deciduous trees, we tested the impact of mild elevated temperature (+2.5-3.5 °C; temperature, on average, kept at 10 °C) in mid and late autumn on the bud dormancy depth and spring phenology of beech. We studied saplings by inducing periods of warming in greenhouses over a 2-year period. Even though warming reduced chilling accumulation in both years, we observed that the response of dormancy depth and spring budburst were year-specific. We found that warming during endodormancy peak could decrease the bud dormancy depth and therefore advance spring budburst. This effect appears to be modulated by factors such as the date of senescence onset and forcing intensity during endodormancy. Results from this study suggest that not only chilling but also forcing controls bud development during endodormancy and that extra forcing in autumn can offset reduced chilling.

Potassium Nitrate and Ascorbic Acid Priming Improved Tissue Chemical Composition and Antioxidant and Antimicrobial Activities of Linseed (Linum usitatissimum L.) Sprouts

Potassium nitrate (KNO3) and ascorbic acid (AsA) priming can effectively boost biomass accumulation and nutritional value of plants; nevertheless, few studies investigated their effects on seed sprouting. Thus, we aimed to explore the effects of KNO3 and AsA priming on linseed (Linum usitatissimum L.) sprout growth and assess the changes in bioactive compound levels, which provide valuable insights into the potential benefits of these priming treatments on sprout quality and nutritional value. To this end, germination, biomass accumulation, photosynthetic pigments, primary and secondary metabolites, and mineral profiles in the primed sprouts were evaluated. Moreover, to assess the impact on biological value, we determined the antioxidant and antimicrobial activities of the treated sprout extract. A marked enhancement was observed in germination and pigment levels of KNO3- and AsA-primed sprouts. These increases were in line with induced primary metabolites (e.g., carbohydrate and amino acid contents), particularly under KNO3 treatment. There was also an increase in amino acid metabolism (e.g., increased GS, GDH, and GOGAT enzyme activities), nitrogen level, and nitrate reductase (NR) activity. The linseed sprouts primed with AsA exhibited strong antioxidant and antibacterial activities. Consistently, high levels of polyphenols, flavonoids, total AsA, and tocopherols, as well as improved activity of antioxidant enzymes [peroxidase (POX), catalase (CAT), and superoxide dismutase (SOD)], were recorded. This study proposes KNO3 and AsA priming as an innovative approach to improving the nutritional and health-promoting properties of linseed sprouts. This knowledge will contribute to a better understanding of the biochemical processes involved in improving the nutritional quality and functional benefits of linseed sprouts.

Thymus Vulgaris Oil Nanoemulsion: Synthesis, Characterization, Antimicrobial and Anticancer Activities

Essential oil nanoemulsions have received much attention due to their biological activities. Thus, a thyme essential oil nanoemulsion (Th-nanoemulsion) was prepared using a safe and eco-friendly method. DLS and TEM were used to characterize the prepared Th-nanoemulsion. Our findings showed that the nanoemulsion was spherical and ranged in size from 20 to 55.2 nm. The micro-broth dilution experiment was used to evaluate the in vitro antibacterial activity of a Th-emulsion and the Th-nanoemulsion. The MIC50 values of the thymol nanoemulsion were 62.5 mg/mL against Escherichia coli and Klebsiella oxytoca, 250 mg/mL against Bacillus cereus, and 125 mg/mL against Staphylococcus aureus. Meanwhile, it emerged that the MIC50 values of thymol against four strains were not detected. Moreover, the Th-nanoemulsion exhibited promising antifungal activity toward A. brasiliensis and A. fumigatus, where inhibition zones and MIC50 were 20.5 ± 1.32 and 26.4 ± 1.34 mm, and 12.5 and 6.25 mg/mL, respectively. On the other hand, the Th-nanoemulsion displayed weak antifungal activity toward C. albicans where the inhibition zone was 12.0 ± 0.90 and MIC was 50 mg/mL. Also, the Th-emulsion exhibited antifungal activity, but lower than that of the Th-nanoemulsion, toward all the tested fungal strains, where MIC was in the range of 12.5-50 mg/mL. The in vitro anticancer effects of Taxol, Th-emulsion, and Th-nanoemulsion were evaluated using the standard MTT method against breast cancer (MCF-7) and hepatocellular carcinoma (HepG2). Additionally, the concentration of VEGFR-2 was measured, and the activities of caspase-8 (casp-8) and caspase-9 (casp-9) were evaluated. The cytotoxic effect was the most potent against the MCF-7 breast cancer cell line after the Th-nanoemulsion treatment (20.1 ± 0.85 µg/mL), and was 125.1 ± 5.29 µg/mL after the Th-emulsion treatment. The lowest half-maximal inhibitory concentration (IC50) value, 20.1 ± 0.85 µg/mL, was achieved when the MCF-7 cell line was treated with the Th-nanoemulsion. In addition, Th-nanoemulsion treatments on MCF-7 cells led to the highest elevations in casp-8 and casp-9 activities (0.66 ± 0.042 ng/mL and 17.8 ± 0.39 pg/mL, respectively) compared to those with Th-emulsion treatments. In comparison to that with the Th-emulsion (0.982 0.017 ng/mL), the VEGFR-2 concentration was lower with the Th-nanoemulsion treatment (0.672 ± 0.019ng/mL). In conclusion, the Th-nanoemulsion was successfully prepared and appeared in nanoform with a spherical shape according to DLS and TEM, and also exhibited antibacterial, antifungal, as well as anticancer activities.

The effects of microbial fertilizers application on growth, yield and some biochemical changes in the leaves and seeds of guar (Cyamopsis tetragonoloba L.)

Guar (Cyamopsis tetragonoloba L.) is a summer legume that is becoming a crucial industrial crop because of its high gum and protein content. Thus far, the combined effects of arbuscular mycorrhizal fungi (AMF) and Bradyrhizobium on the yield and chemical composition of guar plants are not well studied. Therefore, the current investigation was designed to estimate the individual as well as the combined effects of AMF and Bradyrhizobium on plant growth, yield and nutritional quality of seeds and leaves of guar. AMF and/or Bradyrhizobium inoculation improved chemical composition of guar seeds and its morpho-physiological (plant height, fresh weight, dry weight, and yield production) traits. In addition to increased guar growth and yield production, the inoculation of AMF and/or Bradyrhizobium increased guar leaf and seed minerals, fiber, lipids, crude protein and ash contents. At primary metabolites, there were increases in sugar levels including raffinose stachyose, verbascose and galactomannan. These increases in sugar provided a route for organic acids, amino acids and fatty acids production. Interestingly, there was an increase in essential amino acids and unsaturated fatty acids. At the bioactive secondary metabolite levels, biofertilizers improved phenols and flavonoids levels and anthocyanin and polyamines biosynthesis. In line with these increases, precursors of anthocyanin (phenylalanine, p-coumaric acid, and cinnamic acid) and the levels of polyamines (diaminopropane, putrescine, cadaverine, spermidine, spermine, and agmatine) were increased. Overall, for the first time, our study shed the light on how AMF and Bradyrhizobium improved guar yield and metabolism. Our findings suggested that the combined inoculation of AMF and Bradyrhizobium is an innovative approach to improve guar growth, yield production and yield quality.

Wound Dressing Scaffold with High Anti-biofilm Performance Based on Ciprofloxacin-Loaded Chitosan-Hydrolyzed Starch Nanocomposite: In Vitro and In Vivo Study

Today, the search for solutions to reduce wound infection and restore wound receptivity also reduces its side effects which are a difficult problem in medical science research. The greatest options for this purpose are hydrogel dressings since they are compatible with tissue and have an antibacterial effect on wound healing. Chronic wounds represent a significant burden on people and healthcare systems worldwide. Bacteria often enter such skin wounds, causing irritation and complicating the healing process. In addition, bacteria cause infection, which inhibits rejuvenation and the production of collagen. This study is aimed at developing novel chitosan (CS)-hydrolyzed starch nanocomposite (HS/Ch-NC) loaded with ciprofloxacin to enhance its skin retention and wound healing efficacy and anti-biofilm efficacy. Drug-loading on the (HS/Ch-NC) and encapsulation efficiency was 55.2% and 97.2%, respectively. The activity of HS-NC loaded with ciprofloxacin as anti-biofilm activity by 72% and 63% against Enterobacter aerogenes and Pseudomonas aeruginosa, respectively. The obtained (HS/Ch-NC) loaded with ciprofloxacin is a promising candidate for the development of improved bandage materials, as cell viability and proliferation was assessed using an SRB assay with half-maximal inhibitory concentrations (IC50) at 119.1 µg/ml. In vitro scratch wound healing assay revealed significant (p ≤ 0.05) acceleration in wound closure at 24 h enhanced by 56.04% 24-h and 100% 72-h post-exposure to (HS/Ch-NC) loaded ciprofloxacin, compared to the negative control. In vivo skin retention study revealed that (HS/Ch-NC)-loaded ciprofloxacin showed 3.65-fold higher retention, respectively, than ciprofloxacin. Thus, our study assumes that ciprofloxacin-loaded HS-NC is a potential delivery system for enhancing ciprofloxacin skin retention and wound healing activity.

Arbuscular mycorrhizal fungi as an effective approach to enhance the growth and metabolism of soybean plants under thallium (TI) toxicity

Thallium (TI) is a toxic metal that can trigger harmful impacts on growth and metabolism of plants. Utilizing arbuscular mycorrhizal fungi (AMF) proves to be an effective strategy for alleviating heavy metal toxicity in plants. To this end, AMF were applied to mitigate TI toxic effects on the growth, primary and secondary metabolism of soybean plants. Here, TI stress inhibited the growth and photosynthetic parameters of soybean plants. It also increased the oxidative damage as demonstrated by increased levels of oxidative markers, (MDA and lipoxygenase (LOX) activity). However, AMF could mitigate the reduction in growth and photosynthesis induced by TI, as well as the induction of oxidative damage. To overcome TI toxicity, AMF increased the levels and metabolism of osmolytes such as proline in soybean plants. This was in line with the increased activities of key enzymes that involved in proline biosynthesis (e.g., P5CS (pyrroline-5-carboxylate synthetase), P5CR (pyrroline-5-carboxylate reductase) and OAT (ornithine aminotransferase) under the AMF and/or TI treatments. Furthermore, soybean plants could benefit from the synergism between AMF and TI to enhance the contents of individual (e.g., spermine and spermidine) and total polyamines as well as their metabolic enzymes (e.g., arginine decarboxylase and ornithine decarboxylase). Overall, the combined application of AMF emerges as a viable approach for alleviating TI toxicity in soybean plants.

Environmental and anthropogenic drivers of watercress (Nasturtium officinale) communities in char-lands and water channels across the Swat River Basin: implication for conservation planning

Recent anthropogenic sources and excess usage have immensely threatened the communities and habitat ecology of this region's medicinally and economically significant crops. Therefore, our study aims to evaluate the community structure and related environmental characteristics sustaining Nasturtium officinale communities along the river basin (RB) in Northwest Pakistan, using the clustering procedure (Ward's method) and Redundancy analysis (RDA). From 340 phytosociological plots (34 × 10 = 340), we identified four ecologically distinct assemblages of N. officinale governed by different environmental and anthropogenic factors for the first time. The floristic structure shows the dominance of herbaceous (100%), native (77%), and annual (58.09%) species indicating relatively stable communities; however, the existence of the invasive plants (14%) is perturbing and may cause instability in the future, resulting in the replacement of herbaceous plant species. Likewise, we noticed apparent variations in the environmental factors, i.e., clay percentage (p = 3.1 × 10-5), silt and sand percentage (p< 0.05), organic matter (p< 0.001), phosphorus and potassium (p< 0.05), and heavy metals, i.e., Pb, Zn, and Cd (p< 0.05), indicating their dynamic role in maintaining the structure and composition of these ecologically distinct communities. RDA has also demonstrated the fundamental role of these factors in species-environment correlations and explained the geospatial variability and plants' ecological amplitudes in the Swat River wetland ecosystem. We concluded from this study that N. officinale communities are relatively stable due to their rapid colonization; however, most recent high anthropogenic interventions especially overharvesting and sand mining activities, apart from natural enemies, water deficit, mega-droughts, and recent flood intensification due to climate change scenario, are robust future threats to these communities. Our research highlights the dire need for the sustainable uses and conservation of these critical communities for aesthetics, as food for aquatic macrobiota and humans, enhancing water quality, breeding habitat, fodder crop, and its most promising medicinal properties in the region.

Watermelon Rind Mediated Biosynthesis of Bimetallic Selenium-Silver Nanoparticles: Characterization, Antimicrobial and Anticancer Activities

One of the most hazardous diseases that influences human health globally is microbial infection. Therefore, bimetallic nanoparticles have received much attention for controlling microbial infections in the current decade. In the present study, bimetallic selenium-silver nanoparticles (Se-Ag NPs) were effectively biosynthesized using watermelon rind WR extract through the green technique for the first time. UV-visible spectroscopy, transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy (EDX) methods were used to characterize the produced NPs. The results indicated that the bimetallic Se-Ag NPs had synergistic antimicrobial activity at low concentrations, which helped to reduce the toxicity of Ag NPs after the bimetallic Se-Ag NPs preparation and increase their great potential. Se-Ag NPs with sizes ranging from 18.3 nm to 49.6 nm were detected by TEM. Se-Ag NP surfaces were uniformly visible in the SEM picture. The cytotoxicity of bimetallic Se-Ag NPs was assessed against the Wi38 normal cell line to check their safety, where the IC50 was 168.42 µg/mL. The results showed that bimetallic Se-Ag NPs had antibacterial action against Candida albicans, Escherichia coli, Pseudomonas aeruginosa, Klebsiella oxytoca, Bacillus subtilis, and Staphylococcus aureus with a minimum inhibitory concentration (MIC) of 12.5 to 50 µg/mL. Additionally, bimetallic Se-Ag NPs had promising anticancer activity toward the MCF7 cancerous cell line, where the IC50 was 21.6 µg/mL. In conclusion, bimetallic Se-Ag NPs were biosynthesized for the first time using WR extract, which had strong antibacterial, antifungal and anticancer properties.

Elevated CO2 reduced antimony toxicity in wheat plants by improving photosynthesis, soil microbial content, minerals, and redox status

Introduction

Antimony (Sb), a common rare heavy metal, is naturally present in soils at low concentrations. However, it is increasingly used in industrial applications, which in turn, leads to an increased release into the environment, exerting a detrimental impact on plant growth. Thus, it is important to study Sb effects on plants under the current and future CO2 (eCO2).

Methods

To this end, high Sb concentrations (1500 mg/kg soil) effects under ambient (420 ppm) and eCO2 (710 ppm) on wheat growth, physiology (photosynthesis reactions) and biochemistry (minerals contents, redox state), were studied and soil microbial were evaluated.

Results and discussion

Our results showed that Sb uptake significantly decreased wheat growth by 42%. This reduction could be explained by the inhibition in photosynthesis rate, Rubisco activity, and photosynthetic pigments (Cha and Chb), by 35%, 44%, and 51%, respectively. Sb significantly reduced total bacterial and fungal count and increased phenolic and organic acids levels in the soil to decrease Sb uptake. Moreover, it induced oxidative markers, as indicated by the increased levels of H2O2 and MDA (1.96 and 2.8-fold compared to the control condition, respectively). To reduce this damage, antioxidant capacity (TAC), CAT, POX, and SOD enzymes activity were increased by 1.61, 2.2, 2.87, and 1.86-fold, respectively. In contrast, eCO2 mitigated growth inhibition in Sb-treated wheat. eCO2 and Sb coapplication mitigated the Sb harmful effect on growth by reducing Sb uptake and improving photosynthesis and Rubisco enzyme activity by 0.58, 1.57, and 1.4-fold compared to the corresponding Sb treatments, respectively. To reduce Sb uptake and improve mineral availability for plants, a high accumulation of phenolics level and organic acids in the soil was observed. eCO2 reduces Sb-induced oxidative damage by improving redox status. In conclusion, our study has provided valuable insights into the physiological and biochemical bases underlie the Sb-stress mitigating of eCO2 conditions. Furthermore, this is important step to define strategies to prevent its adverse effects of Sb on plants in the future.

Chromium(VI) Toxicity and Active Tolerance Mechanisms of Wheat Plant Treated with Plant Growth-Promoting Actinobacteria and Olive Solid Waste

The present study aimed to assess the potential of plant growth-promoting Actinobacteria and olive solid waste (OSW) in ameliorating some biochemical and molecular parameters of wheat (Triticum aestivum) plants under the toxicity of high chromium levels in the soil. With this aim, a pot experiment was conducted, where the wheat plants were treated with a consortium of four Actinobacterium sp. (Bf treatment) and/or OSW (4% w/w) under two levels of nonstress and chromium stress [400 mg Cr(VI) per kg of soil] to estimate the photosynthetic traits, antioxidant protection machine, and detoxification activity. Both Bf and OSW treatments improved the levels of chlorophyll a (+47-98%), carotenoid (+324-566%), stomatal conductance (+17-18%), chlorophyll fluorescence (+12-28%), and photorespiratory metabolism (including +44-72% in glycolate oxidase activity, +6-72% in hydroxypyruvate reductase activity, and +5-44% in a glycine to serine ratio) in leaves of stressed plants as compared to those in the stressed control, which resulted in higher photosynthesis capacity (+18-40%) in chromium-stressed plants. These results were associated with an enhancement in the content of antioxidant metabolites (+10-117%), of direct reactive oxygen species-detoxifying enzymes (+49-94%), and of enzymatic (+40-261%) and nonenzymatic (+17-175%) components of the ascorbate-glutathione cycle in Bf- and OSW-treated plants under stress. Moreover, increments in the content of phytochelatins (+38-74%) and metallothioneins (+29-41%), as markers of detoxification activity, were recorded in the plants treated with Bf and OSW under chromium toxicity. In conclusion, this study revealed that the application of beneficial Actinobacteria and OSW as biofertilization/supplementation could represent a worthwhile consequence in improving dry matter production and enhancing plant tolerance and adaptability to chromium toxicity.

Soil Contamination with Europium Induces Reduced Oxidative Damage in Hordeum vulgare Grown in a CO2-Enriched Environment

The extensive and uncontrolled utilization of rare earth elements, like europium (Eu), could lead to their accumulation in soils and biota. Herein, we investigated the impact of Eu on the growth, photosynthesis, and redox homeostasis in barley and how that could be affected by the future CO2 climate (eCO2). The plants were exposed to 1.09 mmol Eu3+/kg soil under either ambient CO2 (420 ppm, aCO2) or eCO2 (620 ppm). The soil application of Eu induced its accumulation in the plant shoots and caused significant reductions in biomass- and photosynthesis-related parameters, i.e., chlorophyll content, photochemical efficiency of PSII, Rubisco activity, and photosynthesis rate. Further, Eu induced oxidative stress as indicated by higher levels of H2O2 and lipid peroxidation products, and lower ASC/DHA and GSH/GSSG ratios. Interestingly, the co-application of eCO2 significantly reduced the accumulation of Eu in plant tissues. Elevated CO2 reduced the Eu-induced oxidative damage by supporting the antioxidant defense mechanisms, i.e., ROS-scavenging molecules (carotenoids, flavonoids, and polyphenols), enzymes (CAT and peroxidases), and ASC-GSH recycling enzymes (MDHAR and GR). Further, eCO2 improved the metal detoxification capacity by upregulating GST activity. Overall, these results provide the first comprehensive report for Eu-induced oxidative phytotoxicity and how this could be mitigated by eCO2.

Alleviation of gadolinium stress on Medicago by elevated atmospheric CO2 is mediated by changes in carbohydrates, Anthocyanin, and proline metabolism

Rare earth elements (REE) like Gadolinium (Gd), are increasingly used in industry and agriculture and this is concomitant with the increasingly leaking of Gd into the environment. Under a certain threshold concentration, REE can promote plant growth, however, beyond this concentration, they exert negative effects on plant growth. Moreover, the effect of Gd on plants growth and metabolism under a futuristic climate with increasingly atmospheric CO2 has not yet been studied. To this end, we investigated the effect of soil contamination with Gd (150 mg/kg soil) on the growth, carbohydrates, proline, and anthocyanin metabolism of Medicago plants grown under ambient (aCO2, 410 ppm) or elevated CO2 (eCO2, 720 ppm) concentration. Gd negatively affected the growth and photosynthesis of plants and imposed oxidative stress i.e., increased H2O2 and lipid peroxidation (MDA) level. As defense lines, the level and metabolism of osmoprotectants (soluble sugars and proline) and antioxidants (phenolics, anthocyanins, and tocopherols) were increased under Gd treatment. High CO2 positively affected the growth and metabolism of Medicago plants. Moreover, eCO2 mitigated the negative impacts of Gd on Medicago growth. It further induced the levels of osmoprotectants and antioxidants. In line with increased proline and anthocyanins, their metabolic enzymes (e.g. OAT, P5CS, PAL, and CS) were also increased. This study advances our understanding of how Gd adversely affects Medicago plant growth and metabolism. It also sheds light on the biochemical mechanisms underlying the Gd stress-reducing impact of eCO2.

Elevated CO2 differentially attenuates beryllium-induced oxidative stress in oat and alfalfa

Elevated CO2 (eCO2 ) is one of the climate changes that may benefit plant growth under emerging soil contaminants such as heavy metals. In this regard, the morpho-physiological mechanisms underlying the mitigating impact of eCO2 on beryllium (Be) phytotoxicity are poorly known. Hence, we investigated eCO2 and Be interactive effects on the growth and metabolism of two species from different groups: cereal (oat) and legume (alfalfa). Be stress significantly reduced the growth and photosynthetic attributes in both species, but alfalfa was more susceptible to Be toxicity. Be stress induced reactive oxygen species (ROS) accumulation by increasing photorespiration, subsequently resulting in increased lipid and protein oxidation. However, the growth inhibition and oxidative stress induced by Be stress were mitigated by eCO2 . This could be explained, at least partially, by the increase in organic acids (e.g., citric acid) released into the soil, which subsequently reduced Be uptake. Additionally, eCO2 reduced cellular oxidative damage by reducing photorespiration, which was more significant in alfalfa plants. Furthermore, eCO2 improved the redox status and detoxification processes, including phytochelatins, total glutathione and metallothioneins levels, and glutathione-S-transferase activity in both species, but to a greater extend in alfalfa. In this context, eCO2 also stimulated anthocyanin biosynthesis by accumulating its precursors (phenylalanine, coumaric acid, cinnamic acid, and naringenin) and key biosynthetic enzymes (phenylalanine ammonia-lyase, cinnamate hydroxylase, and coumarate:CoA ligase) mainly in alfalfa plants. Overall, this study explored the mechanistic approach by which eCO2 alleviates the harmful effects of Be. Alfalfa was more sensitive to Be stress than oats; however, the alleviating impact of eCO2 on Be stress was more pronounced in alfalfa.

How could actinobacteria augment the growth and redox homeostasis in barley plants grown in TiO2NPs-contaminated soils? A growth and biochemical study

The increases in titanium dioxide nanoparticles (TiO2-NPs) released into the environment have raised concerns about their toxicity. However, their phytotoxic impact on plants is not well studied. Therefore, this study aimed at a deeper understanding of the TiO2-NPs phytotoxic impact on barley (Hordeum vulgare) growth and stress defense. We also hypothesized that soil inoculation with bioactive Rhodospirillum sp. JY3 strain can be applied as a biological fertilizer to alleviate TiO2-NPs phytotoxicity. At TiO2-NPs phytotoxicity level, photosynthesis was significantly retarded (∼50% reduction) in TiO2-NPs treated-barley plants which accordingly affect the biomass of barley plants. This retardation was accompanied by a remarkable induction of oxidative damage (H2O2, lipid peroxidation) with a concomitant reduction in the antioxidant defense metabolism. At a glance, Rhodospirillum sp. JY3 ameliorated the reduction in growth by enhancing the photosynthetic efficiency in contaminated barley plants. Moreover, Rhodospirillum sp. JY3 inoculation reduced the oxidative damage induced by TiO2-NPs via quenching H2O2 production and lipid peroxidation. Regarding the antioxidant defense arsenal, Rhodospirillum sp. JY3 enhanced both enzymatic (e.g. peroxidase (POX), catalase (CAT), superoxide dismutase (SOD), …. etc.) and non-enzymatic (glutathione (GSH), ascorbate (ASC), polyphenols, flavonoids, tocopherols) antioxidants in shoots and to a greater extent roots of barley plants. Moreover, the inoculation significantly enhanced the heavy metal-detoxifying metabolites (eg. phytochelatins, glutaredoxin, thioredoxin, peroxiredoxin) as well as metal-detoxifying enzymes in barley shoots and more apparently in roots of TiO2-NPs stressed plants. Furthermore, there was an organ-specific response to TiO2-NPs and Rhodospirillum sp. JY3. To this end, this study shed light, for the first time, on the molecular bases underlie TiO2-NPs stress mitigating impact of Rhodospirillum sp. JY3 and it introduced Rhodospirillum sp. JY3 as a promising eco-friendly tool in managing environmental risks to maintain agricultural sustainability.

B2 O3 nanoparticles alleviate salt stress in maize leaf growth zones by enhancing photosynthesis and maintaining mineral and redox status

Salt stress induces significant loss in crop yield worldwide. Although the growth-stimulating effects of micronutrient nanoparticles (NPs) application under salinity have been studied, the molecular and biochemical mechanisms underlying these effects are poorly understood. The large size of maize leaf growth zones provides an ideal model system to sample and investigate the molecular and physiological bases of growth at subzonal resolution. Using kinematic analysis, our study indicated that salinity at 150 mM inhibited maize leaf growth by decreasing cell division and expansion in the meristem and elongation zones. Consistently, salinity downregulated cell cycle gene expression (wee1, mcm4, and cyclin-B2-4). B2 O3 NP (BNP) mitigated the stress-induced growth inhibition by reducing the decrease in cell division and expansion. BNP also enhanced the photosynthesis-related parameters. Simultaneously, chlorophyll, phosphoenolpyruvate carboxylase and ribulose-1,5-bisphosphate carboxylase/oxygenase were stimulated in the mature zone. Concomitant with growth stimulation by BNP, mineral homeostasis, particularly for B and Ca, was monitored. BNP reduced oxidative stress (e.g., lessened H2 O2 generation along the leaf zones and reduced lipid peroxidation in the mature zone) induced by salinity. This resulted from better maintenance of the redox status, that is, increased the glutathione-ascorbate cycle in the meristem and elongation zones, and flavonoids and tocopherol levels in the mature zone. Our study has important implications for assessing the salinity stress impact mitigated by BNP on maize growth, providing a basis to improve the resilience of crop species under salinity stress conditions.

Spatial distribution of the four invasive plants and their impact on natural communities' dynamics across the arid and semi-arid environments in northwest Pakistan

Introduction

Non-native species are globally successful invaders with negative impacts on vegetation communities' social, economic, and ecological values. Hence, the current research was carried out to assess the spatial distribution patterns and vegetative diversity of the four non-native species in severely invaded areas of the semi-arid parts of northern Pakistan.

Methods

The research was conducted using data from 1065 plots spread across 165 sites. These sites represented habitats throughout Northern Province, such as farm countryside, highlands, and abandoned places in rural and urban areas.

Results and discussion

The communities were floristically diverse, represented by 107 plant species, and dominated mainly by annual and perennial life forms with herbaceous habits. Similarly, the floristic structure shows significant variation tested by the χ2 test (P< 0.05) for plant status, life forms, life cycle, and habitat base distribution. In addition, the diversity indices show significant variation having the highest diversity in C-III (P. hysterophorus-dominated sites) and lowest in C-IV (S. marianum-dominated sites, i.e., primarily pure communities), indicating non-native species may increase or decrease site diversity. The diversity communities were further supported by higher quantities of soil nutrients, i.e., organic percentage (2.22 ± 0.04). Altitude, soil nutrients, and texture were shown to be the environmental factors most associated with communities that non-native species had invaded.

Recommendation

It is recommended that relevant, additional soil and climatic parameters be integrated into species distribution models to improve our understanding of the ecological niches of different species and to make a collective approach for preserving and conserving native plant communities.

Antimicrobial, Antibiofilm, and Anticancer Activities of Syzygium aromaticum Essential Oil Nanoemulsion

In the current study, clove oil nanoemulsion (CL-nanoemulsion) and emulsion (CL-emulsion) were prepared through an ecofriendly method. The prepared CL-nanoemulsion and CL-emulsion were characterized using dynamic light scattering (DLS) and a transmission electron microscope (TEM), where results illustrated that CL-nanoemulsion droplets were approximately 32.67 nm in size and spherical in shape, while CL-nanoemulsion droplets were approximately 225.8 nm with a spherical shape. The antibacterial activity of CL-nanoemulsion and CL-emulsion was carried out using a microbroth dilution method. Results revealed that the preferred CL-nanoemulsion had minimal MIC values between 0.31 and 5 mg/mL. The antibiofilm efficacy of CL-nanoemulsion against S. aureus significantly decreased the development of biofilm compared with CL-emulsion. Furthermore, results illustrated that CL-nanoemulsion showed antifungal activity significantly higher than CL-emulsion. Moreover, the prepared CL-nanoemulsion exhibited outstanding antifungal efficiency toward Candida albicans, Cryptococcus neoformans, Aspergillus brasiliensis, A. flavus, and A. fumigatus where MICs were 12.5, 3.12, 0.78, 1.56, and 1.56 mg/mL, respectively. Additionally, the prepared CL-nanoemulsion was analyzed for its antineoplastic effects through a modified MTT assay for evaluating apoptotic and cytotoxic effects using HepG2 and MCF-7 cell lines. MCF-7 breast cancer cells showed the lowest IC50 values (3.4-fold) in CL-nanoemulsion relative to that of CL-emulsion. Thus, CL-nanoemulsion induces apoptosis in breast cancer cells by inducing caspase-8 and -9 activity and suppressing VEGFR-2. In conclusion, the prepared CL-nanoemulsion had antibacterial, antifungal, and antibiofilm as well as anticancer properties, which can be used in different biomedical applications after extensive studies in vivo.

Correction: Unveiling anticancer, antimicrobial, and antioxidant activities of novel synthesized bimetallic boron oxide-zinc oxide nanoparticles

[This corrects the article DOI: 10.1039/D3RA03413E.].

Synergistic Impacts of Plant-Growth-Promoting Bacteria and Selenium Nanoparticles on Improving the Nutritional Value and Biological Activities of Three Cultivars of Brassica Sprouts

Due to the growing world population and increasing environmental stress, improving the production, nutritional quality, and pharmaceutical applications of plants have become an urgent need. Therefore, current research was designed to investigate the impact of seed priming using plant-growth-promoting bacteria (PGPB) along with selenium nanoparticles (SeNPs) treatment on chemical and biological properties of three Brassica oleracea cultivars [Southern star (VA1), Prominence (VA2), Monotop (VA3)]. With this aim, one out of five morphologically different strains of bacteria, namely, JM18, which was further identified via 16S rRNA gene sequencing as a Nocardiopsis species with strong plant-growth-promoting traits, isolated from soil, was used. To explore the growth-promoting potential of Nocardiopsis species, seeds of three varieties of B. oleracea were primed with JM18 individually or in combination with SeNP treatment. Seed treatments increased sprout growth (fresh and dry weights) and glucosinolate accumulation. The activity of myrosinase was significantly increased through brassica sprouts and consequently enhanced the amino-acid-derived glucosinolate induction. Notably, a reduction in effective sulforaphane nitrile was detected, being positively correlated with a decrease in epithiospecifier protein (EP). Consequently, the antioxidant activities of VA2 and VA3, determined by the ferric reducing antioxidant power (FRAP) assay, were increased by 74 and 79%, respectively. Additionally, the antibacterial activities of JM18-treated cultivars were improved. However, a decrease was observed in SeNP- and JM18 + SeNP-treated VA2 and VA3 against Serratia marcescens and Candida glabrata and VA1 against S. marcescens. In conclusion, seed priming with the JM18 extract is a promising method to enhance the health-promoting activities of B. oleracea sprouts.

Technological Quality of Sugarcane Inoculated with Plant-Growth-Promoting Bacteria and Residual Effect of Phosphorus Rates

Phosphate fertilization in highly weathered soils has been a major challenge for sugarcane production. The objective of this work was to evaluate the foliar levels of phosphorus (P) and nitrogen (N) and the technological quality and productivity of second ratoon cane as a function of inoculation with plant-growth-promoting bacteria (PGPBs) together with the residual effect of phosphate fertilization. The experiment was carried out at the research and extension farm of Ilha Solteira, state of São Paulo, Brazil. The experiment was designed in a randomized block with three replications in a 5 × 8 factorial scheme. The treatments consisted of five residual doses of phosphorus (0, 45, 90, 135 and 180 kg ha^-1 of P₂O₅, 46% P) applied at planting from the source of triple superphosphate and eight inoculations from three species of PGPB (Azospirillum brasilense, Bacillus subtilis and Pseudomonas fluorescens), applied in single or co-inoculation at the base of stems of sugarcane variety RB92579. Inoculation with PGPBs influenced leaf N concentration, while inoculations with Pseudomonas fluorescens and combinations of bacteria together with the highest doses exerted a positive effect on leaf P concentration. Co-inoculation with A. brasilense + Pseudomonas fluorescens associated with a residual dose of 135 kg ha^-1 of P₂O₅ increased stem productivity by 42%. Thus, it was concluded that inoculations with Pseudomonas fluorescens and their combinations are beneficial for the sugarcane crop, reducing phosphate fertilization and increasing productivity.

Exploring Exogenous Indole-3-acetic Acid's Effect on the Growth and Biochemical Profiles of Synechocystis sp. PAK13 and Chlorella variabilis

Microalgae have garnered scientific interest for their potential to produce bioactive compounds. However, the large-scale industrial utilization of microalgae faces challenges related to production costs and achieving optimal growth conditions. Thus, this study aimed to investigate the potential role of exogenous indole-3-acetic acid (IAA) application in improving the growth and production of bioactive metabolites in microalgae. To this end, the study employed different concentrations of exogenously administered IAA ranging from 0.36 µM to 5.69 µM to assess its influence on the growth and biochemical composition of Synechocystis and Chlorella. IAA exposure significantly increased IAA levels in both strains. Consequentially, improved biomass accumulation in parallel with increased total pigment content by approximately eleven-fold in both strains was observed. Furthermore, the application of IAA stimulated the accumulation of primary metabolites. Sugar levels were augmented, providing a carbon source that facilitated amino acid and fatty acid biosynthesis. As a result, amino acid levels were enhanced as well, leading to a 1.55-fold increase in total amino acid content in Synechocystis and a 1.42-fold increase in Chlorella. Total fatty acids content increased by 1.92-fold in Synechocystis and by 2.16-fold in Chlorella. Overall, the study demonstrated the effectiveness of exogenously adding IAA as a strategy for enhancing the accumulation of microalgae biomass and biomolecules. These findings contribute to the advancement of microalgae-based technologies, opening new avenues to produce economically important compounds derived from microalgae.

Physiological and biochemical responses of wheat to synergistic effects of selenium nanoparticles and elevated CO2 conditions

Elevating CO₂ (eCO₂) levels will change behavior and the effect of soil fertilizers and nutrients. Selenium NPs (SeNPs) have arisen as an alternative to conventional Se fertilizers to enrich crops. However, it remains unclear whether eCO₂ will change the biological effects of soil SeNPs on plant growth and metabolism. The current study aimed to shed new light on the interactive impacts of eCO₂ and SeNPs on wheat plants. Accordingly, the attempts were to reveal whether the application of SeNPs can modulate the eCO₂ effects on wheat (Triticum aestivum L.) physiological and biochemical traits. With this goal, a pot experiment was carried out where the seeds were primed with SeNPs and plants were grown under two levels of CO₂ concentrations (ambient CO₂ (aCO₂, 410 μmol CO₂ mol^-1; and eCO₂ (710 μmol CO₂ mol^-1)) during six weeks after sowing. Although SeNPs+eCO₂ treatment resulted in the highest accumulation of photosynthetic pigment content in leaves (+49-118% higher than control), strong evidence of the positive impacts on Rubisco activity (~+23%), and stomatal conductance (~+37%) was observed only under eCO₂, which resulted in an improvement in photosynthesis capacity (+42%). When photosynthesis parameters were stimulated with eCO₂, a significant improvement in dry matter production was detected, in particular under SeNPs+eCO₂ which was 1.8 times higher than control under aCO₂. The highest content of antioxidant enzymes, molecules, and metabolites was also recorded in SeNPs+eCO₂, which might be associated with the nearly 50% increase in sodium content in shoots at the same treatment. Taken together, this is the first research documenting the effective synergistic impacts of eCO₂ and SeNPs on the mentioned metabolites, antioxidants, and some photosynthetic parameters, an advantageous consequence that was not recorded in the individual application of these treatments, at least not as broadly as with the combined treatment.

Unveiling anticancer, antimicrobial, and antioxidant activities of novel synthesized bimetallic boron oxide-zinc oxide nanoparticles

Bimetallic nanoparticles have received much attention recently due to their multifunctional applications, and synergistic potential at low concentrations. In the current study, bimetallic boron oxide-zinc oxide nanoparticles (B₂O₃-ZnO NPs) were synthesized by an eco-friendly, and cost-effective method through the utilization of gum arabic in the presence of gamma irradiation. Characterization of the synthesized bimetallic B₂O₃-ZnO NPs revealed the successful synthesis of bimetallic NPs on the nano-scale, and good distribution, in addition to formation of a stable colloidal nano-solution. Furthermore, the bimetallic B₂O₃-ZnO NPs were assessed for anticancer, antimicrobial and antioxidant activities. The evaluation of the cytotoxicity of bimetallic B₂O₃-ZnO NPs on Vero and Wi38 normal cell lines illustrated that bimetallic B₂O₃-ZnO NPs are safe in use where IC₅₀ was 384.5 and 569.2 μg ml^-1, respectively. The bimetallic B₂O₃-ZnO NPs had anticancer activity against Caco 2 where IC₅₀ was 80.1 μg ml^-1. Furthermore, B₂O₃-ZnO NPs exhibited promising antibacterial activity against E. coli, P. aeruginosa, B. subtilis and S. aureus, where MICs were 125, 62.5, 125 and 62.5 μg ml^-1 respectively. Likewise, B₂O₃-ZnO NPs had potential antifungal activity against C. albicans as unicellular fungi (MIC was 62.5 μg ml^-1). Moreover, B₂O₃-ZnO NPs displayed antioxidant activity (IC₅₀ was 102.6 μg ml^-1). In conclusion, novel bimetallic B₂O₃-ZnO NPs were successfully synthesized using gum arabic under gamma radiation, where they displayed anticancer, antimicrobial and antioxidant activities.

Biostimulants in Corn Cultivation as a Means to Alleviate the Impacts of Irregular Water Regimes Induced by Climate Change

Climate change alters regular weather seasonality. Corn is one of the main crops affected by irregular water regimes. Due to complications in decision-making processes related to climate change, it is estimated that planting corn outside the optimal window results in around USD 340 million in losses per year in the United States' Corn Belt. In turn, exogenous plant growth regulators have been gaining prominence due to their potential to positively influence the morphology and physiology of plants under stress. This study was based on the hypothesis that the use of plant growth regulators can assist in mitigating the adverse effects of climate change on corn plants sown both inside and outside the recommended planting period. In this context, the effects of biostimulant application on gas exchange in corn plants sown within and outside the recommended period were evaluated. The experiment was carried out in randomized blocks in a 4 × 5 × 2 factorial scheme with four repetitions. These were four sowing times, the application of the biostimulants via seeds in five doses, and foliar applications (presence and absence). The biostimulant doses were 0.00, 6.25, 12.50, 18.75, and 25 mL kg^-1. The foliar application used a dose of 500 mL ha^-1. Only in the period (2017/2) higher doses of biostimulants indicated a decrease in the water use efficiency of plants, suggesting the need to evaluate this variable carefully. In this regard, future studies may investigate the ideal doses and application timings of biostimulants for different edaphoclimatic conditions. In general, the combined use of biostimulants on seeds and as a foliar treatment boosted physiological activity and stimulated photosynthetic processes in corn plants. Based on these data, plant regulators can be a useful tool to mitigate the adverse effects of climate change on corn plants sown inside and outside the planting period.

Efficient Role of Endophytic Aspergillus terreus in Biocontrol of Rhizoctonia solani Causing Damping-off Disease of Phaseolus vulgaris and Vicia faba

The wide spread of plant pathogens affects the whole world, threatening national food security. Various fungi including Rhizoctonia solani induce the fungal disease damping-off that negatively affects plant seedlings' growth. Recently, endophytic fungi are used as safe alternatives to chemical pesticides that harm plant and human health. Here, an endophytic Aspergillus terreus was isolated from Phaseolus vulgaris seeds to control damping-off diseases by improving the defense system in Phaseolus vulgaris and Vicia faba seedlings. Endophytic fungus was morphologically and genetically identified Aspergillus terreus, and it is deposited in GeneBank under accession OQ338187. A. terreus demonstrated antifungal efficacy against R. solani with an inhibition zone at 22.0 mm. Moreover, the minimum inhibitory concentrations (MIC) of ethyl acetate extract (EAE) of A. terreus were between 0.3125 and 0.625 mg/mL to inhibit R. solani growth. Precisely 58.34% of the Vicia faba plants survived when A. terreus was added compared with the untreated infected (16.67%). Similarly, Phaseolus vulgaris achieved 41.67% compared to the infected (8.33%). Both groups of treated infected plants showed reduced oxidative damage (reduced Malondialdehyde and hydrogen peroxide levels) as compared to untreated infected plants. Reduced oxidative damage was correlated with the increase in photosynthetic pigments and the antioxidant defense system including polyphenol oxidase, peroxidase, catalase, and superoxide dismutase enzyme activities. Overall, the endophytic A. terreus can be considered an effective tool to control the suppression of Rhizoctonia solani in legumes, especially Phaseolus vulgaris and Vicia faba, as an alternative to synthetic chemical pesticides that harm the environment and human health.

Glycine differentially improved the growth and biochemical composition of Synechocystis sp. PAK13 and Chlorella variabilis DT025

The potential of microalgae to produce valuable compounds has garnered considerable attention. However, there are various challenges that hinder their large-scale industrial utilization, such as high production costs and the complexities associated with achieving optimal growth conditions. Therefore, we investigated the effects of glycine at different concentrations on the growth and bioactive compounds production of Synechocystis sp. PAK13 and Chlorella variabilis cultivated under nitrogen availability. Glycine supplementation resulted in increased biomass and bioactive primary metabolites accumulation in both species. Sugar production, particularly glucose content, significantly improved in Synechocystis at 3.33 mM glycine (1.4 mg/g). This led to enhanced organic acid, particularly malic acid, and amino acids production. Glycine stress also influenced the concentration of indole-3-acetic acid, which was significantly higher in both species compared to the control. Furthermore, fatty acids content increased by 2.5-fold in Synechocystis and by 1.36-fold in Chlorella. Overall, the exogenous application of glycine is a cheap, safe, and effective approach to enhancing sustainable microalgal biomass and bioproducts production.