Modeling reveals posttranscriptional regulation of GA metabolism enzymes in response to drought and cold.

The hormone gibberellin (GA) controls plant growth and regulates growth responses to environmental stress. In monocotyledonous leaves, GA controls growth by regulating division-zone size. We used a systems approach to investigate the establishment of the GA distribution in the maize leaf growth zone to understand how drought and cold alter leaf growth. By developing and parameterizing a multiscale computational model that includes cell movement, growth-induced dilution, and metabolic activities, we revealed that the GA distribution is predominantly determined by variations in GA metabolism. Considering wild-type and UBI::GA20-OX-1 leaves, the model predicted the peak in GA concentration, which has been shown to determine division-zone size. Drought and cold modified enzyme transcript levels, although the model revealed that this did not explain the observed GA distributions. Instead, the model predicted that GA distributions are also mediated by posttranscriptional modifications increasing the activity of GA 20-oxidase in drought and of GA 2-oxidase in cold, which we confirmed by enzyme activity measurements. This work provides a mechanistic understanding of the role of GA metabolism in plant growth regulation.

TALE gene family: identification, evolutionary and expression analysis under various exogenous hormones and waterlogging stress in Cucumis sativus L.

BACKGROUND: Three Amino acid Loop Extension (TALE) belongs to the homeobox group of genes that are important constituents of plant systems. The TALE gene family is instrumental not only in growth and development but also plays an essential role in regulating plant response to environmental adversaries. RESULTS: In the present study, we isolated 21 CsTALE genes from the cucumber (Cucumis sativus L.) genome database. Bioinformatics tools were put in place to understand the structural and functional components of the CsTALE gene family. The evolutionary analysis dissected them into seven subclades (KNOX-I, KNOX-II, and BELL-I to BELL-V). The cis-acting elements in the promoter region of CsTALE genes disclosed that they are key regulators of hormonal and stress-related processes. Additionally, the STRING database advocated the concerting role of CsTALE proteins with other key transcription factors potent in plant developmental biology. The CsmiR319 and CsmiR167a-3p targeting the CsTALE15 and CsTALE16, respectively, further assert the importance of the CsTALE gene family posttranscriptional-related processes. Tissue-specific gene expression unfolded the fundamental involvement of CsTALE genes as they were expressed throughout the developmental stages. Under waterlogging stress, the CsTALE17 expressed significantly higher values in WL, WL-NAA, and WL-ETH but not in WL-MeJA-treated samples. CONCLUSIONS: The present study reveals the evolution and functions of the CsTALE gene family in cucumber. Our work will provide a platform that will help future researchers address the issue of waterlogging stress in the Yangtze River Delta.

Enhancing saline stress tolerance in soybean seedlings through optimal NH4+/NO3- ratios: a coordinated regulation of ions, hormones, and antioxidant potential.

BACKGROUND: Nitrogen (N) availability is crucial in regulating plants' abiotic stress resistance, particularly at the seedling stage. Nevertheless, plant responses to N under salinity conditions may vary depending on the soil's NH4+ to NO3- ratio. METHODS: In this study, we investigated the effects of different NH4+:NO3- ratios (100/0, 0/100, 25/75, 50/50, and 75/25) on the growth and physio-biochemical responses of soybean seedlings grown under controlled and saline stress conditions (0-, 50-, and 100-mM L- 1 NaCl and Na2SO4, at a 1:1 molar ratio). RESULTS: We observed that shoot length, root length, and leaf-stem-root dry weight decreased significantly with increased saline stress levels compared to control. Moreover, there was a significant accumulation of Na+, Cl-, hydrogen peroxide (H2O2), and malondialdehyde (MDA) but impaired ascorbate-glutathione pools (AsA-GSH). They also displayed lower photosynthetic pigments (chlorophyll-a and chlorophyll-b), K+ ion, K+/Na+ ratio, and weakened O2•--H2O2-scavenging enzymes such as superoxide dismutase, catalase, peroxidase, monodehydroascorbate reductase, glutathione reductase under both saline stress levels, while reduced ascorbate peroxidase, and dehydroascorbate reductase under 100-mM stress, demonstrating their sensitivity to a saline environment. Moreover, the concentrations of proline, glycine betaine, total phenolic, flavonoids, and abscisic acid increased under both stresses compared to the control. They also exhibited lower indole acetic acid, gibberellic acid, cytokinins, and zeatine riboside, which may account for their reduced biomass. However, NH4+:NO3- ratios caused a differential response to alleviate saline stress toxicity. Soybean seedlings supplemented with optimal ratios of NH4+:NO3- (T3 = 25:75 and T = 4 50:50) displayed lower Na+ and Cl- and ABA but improved K+ and K+/Na+, pigments, growth hormones, and biomass compared to higher NH4+:NO3- ratios. They also exhibited higher O2•--H2O2-scavenging enzymes and optimized H2O2, MDA, and AsA-GSH pools status in favor of the higher biomass of seedlings. CONCLUSIONS: In summary, the NH4+ and NO3- ratios followed the order of 50:50 > 25:75 > 0:100 > 75:25 > 100:0 for regulating the morpho-physio-biochemical responses in seedlings under SS conditions. Accordingly, we suggest that applying optimal ratios of NH4+ and NO3- (25/75 and 50:50) can improve the resistance of soybean seedlings grown in saline conditions.

Germination responses of Lens Culiunaris L. seeds to osmotic potentials at cardinal temperatures using hydrothermal time model.

BACKGROUND: Lentil is a significant legume that are consumed as a staple food and have a significant economic impact around the world. The purpose of the present research on lentil was to assess the hydrothermal time model's capacity to explain the dynamics of Lens culinaris L. var. Markaz-09 seed germination, as well as to ascertain the germination responses at various sub-optimal temperatures (T) and water potentials (Ψ). In order to study lentil seed germination (SG) behavior at variable water potentials (Ψs) and temperatures (Ts). A lab experiment employing the hydrothermal time model was created. Seeds were germinated at six distinct temperatures: 15 0С, 20 0С, 25 0С, 30 0С, 35 0С, and 40 0С, with five Ψs of 0, -0.3, -0.6, -0.9, and - 1.2 MPa in a PEG-6000 (Polyethylene glycol 6000) solution. RESULTS: The results indicated that the agronomic parameters like Germination index (GI), Germination energy (GE), Timson germination index (TGI), were maximum in 25 0C at (-0.9 MPa) and lowest at 40 0C in 0 MPa. On other hand, mean germination time (MGT) value was highest at 15 0C in -1.2 MPa and minimum at 40 0C in (-0.6 MPa) while Mean germination rate (MGR) was maximum at 40 0C in (0 MPa) and minimum at 15 0C in (-0.6 MPa). CONCLUSIONS: The HTT model eventually defined the germination response of Lens culinaris L. var. Markaz-09 (Lentil) for all Ts and Ψs, allowing it to be employed as a predictive tool in Lens culinaris L. var. Markaz-09 (Lentil) seed germination simulation models.

Salicylic acid and Tocopherol improve wheat (Triticum aestivum L.) Physio-biochemical and agronomic features grown in deep sowing stress: a way forward towards sustainable production.

BACKGROUND: The rate of germination and other physiological characteristics of seeds that are germinating are impacted by deep sowing. Based on the results of earlier studies, conclusions were drawn that deep sowing altered the physio-biochemical and agronomic characteristics of wheat (Triticum aestivum L.). RESULTS: In this study, seeds of wheat were sown at 2 (control) and 6 cm depth and the impact of exogenously applied salicylic acid and tocopherol (Vitamin-E) on its physio-biochemical and agronomic features was assessed. As a result, seeds grown at 2 cm depth witnessed an increase in mean germination time, germination percentage, germination rate index, germination energy, and seed vigor index. In contrast, 6 cm deep sowing resulted in negatively affecting all the aforementioned agronomic characteristics. In addition, deep planting led to a rise in MDA, glutathione reductase, and antioxidants enzymes including APX, POD, and SOD concentration. Moreover, the concentration of chlorophyll a, b, carotenoids, proline, protein, sugar, hydrogen peroxide, and agronomic attributes was boosted significantly with exogenously applied salicylic acid and tocopherol under deep sowing stress. CONCLUSIONS: The results of the study showed that the depth of seed sowing has an impact on agronomic and physio-biochemical characteristics and that the negative effects of deep sowing stress can be reduced by applying salicylic acid and tocopherol to the leaves.

Improving plant adaptation to soil antimony contamination: the synergistic contribution of arbuscular mycorrhizal fungus and olive mill waste.

BACKGROUND: This study aimed to investigate the alterations in biochemical and physiological responses of oat plants exposed to antimony (Sb) contamination in soil. Specifically, we evaluated the effectiveness of an arbuscular mycorrhizal fungus (AMF) and olive mill waste (OMW) in mitigating the effects of Sb contamination. The soil was treated with a commercial strain of AMF (Rhizophagus irregularis) and OMW (4% w/w) under two different levels of Sb (0 and 1500 mg kg-1 soil). RESULTS: The combined treatment (OMW + AMF) enhanced the photosynthetic rate (+ 40%) and chlorophyll a (+ 91%) and chlorophyll b (+ 50%) content under Sb condition, which in turn induced more biomass production (+ 67-78%) compared to the contaminated control plants. More photosynthesis in OMW + AMF-treated plants gives a route for phenylalanine amino acid synthesis (+ 69%), which is used as a precursor for the biosynthesis of secondary metabolites, including flavonoids (+ 110%), polyphenols (+ 26%), and anthocyanins (+ 63%) compared to control plants. More activation of phenylalanine ammonia-lyase (+ 38%) and chalcone synthase (+ 26%) enzymes in OMW + AMF-treated plants under Sb stress indicated the activation of phenylpropanoid pathways in antioxidant metabolites biosynthesis. There was also improved shifting of antioxidant enzyme activities in the ASC/GSH and catalytic pathways in plants in response to OMW + AMF and Sb contamination, remarkably reducing oxidative damage markers. CONCLUSIONS: While individual applications of OMW and AMF also demonstrated some degree of plant tolerance induction, the combined presence of AMF with OMW supplementation significantly enhanced plant biomass production and adaptability to oxidative stress induced by soil Sb contamination.

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.

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.

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.

Biochar improves the physical and nutritional quality of soil and plant function.Salinity stress declined the physiological activities and biomass of the crop.Biochar mitigates the salinity stress in soil and enhances the plant functioning.Exposure to both treatments enhances the antioxidant enzyme activity and biomass.

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.

Nanocomposite of Maize offal biomass demonstrated higher dyes removal.FTIR, SEM, BET, XRD and pH_PZC provided vital evidence for dyes adsorption.MOB/MNPs displayed excellent stability and reusability for dyes adsorption.Groundwater samples exposed a higher dyes removal.Results were validated with equilibrium and kinetic adsorption models.

Models for predicting coffee yield from chemical characteristics of soil and leaves using machine learning.

BACKGROUND: Coffee farming constitutes a substantial economic resource, representing a source of income for several countries due to the high consumption of coffee worldwide. Precise management of coffee crops involves collecting crop attributes (characteristics of the soil and the plant), mapping, and applying inputs according to the plants' needs. This differentiated management is precision coffee growing and it stands out for its increased yield and sustainability. RESULTS: This research aimed to predict yield in coffee plantations by applying machine learning methodologies to soil and plant attributes. The data were obtained in a field of 54.6 ha during two consecutive seasons, applying varied fertilization rates in accordance with the recommendations of soil attribute maps. Leaf analysis maps also were monitored with the aim of establishing a correlation between input parameters and yield prediction. The machine-learning models obtained from these data predicted coffee yield efficiently. The best model demonstrated predictive fit results with a Pearson correlation of 0.86. Soil chemical attributes did not interfere with the prediction models, indicating that this analysis can be dispensed with when applying these models. CONCLUSION: These findings have important implications for optimizing coffee management and cultivation, providing valuable insights for producers and researchers interested in maximizing yield using precision agriculture. © 2024 Society of Chemical Industry.

Can biochemical traits bridge the gap between genomics and plant performance? A study in rice under drought.

The possibility of introducing metabolic/biochemical phenotyping to complement genomics-based predictions in breeding pipelines has been considered for years. Here we examine to what extent and under what environmental conditions metabolic/biochemical traits can effectively contribute to understanding and predicting plant performance. In this study, multivariable statistical models based on flag leaf central metabolism and oxidative stress status were used to predict grain yield (GY) performance for 271 indica rice (Oryza sativa) accessions grown in the field under well-watered and reproductive stage drought conditions. The resulting models displayed significantly higher predictability than multivariable models based on genomic data for the prediction of GY under drought (Q2 = 0.54-0.56 versus 0.35) and for stress-induced GY loss (Q2 = 0.59-0.64 versus 0.03-0.06). Models based on the combined datasets showed predictabilities similar to metabolic/biochemical-based models alone. In contrast to genetic markers, models with enzyme activities and metabolite values also quantitatively integrated the effect of physiological differences such as plant height on GY. The models highlighted antioxidant enzymes of the ascorbate-glutathione cycle and a lipid oxidation stress marker as important predictors of rice GY stability under drought at the reproductive stage, and these stress-related variables were more predictive than leaf central metabolites. These findings provide evidence that metabolic/biochemical traits can integrate dynamic cellular and physiological responses to the environment and can help bridge the gap between the genome and the phenome of crops as predictors of GY performance under drought.

A meta-analysis reveals differential sensitivity of cold stress responses in the maize leaf.

Maize (Zea mays), a cold-sensitive crop, requires cold tolerance for extending the length of the growing season in temperate climates. However, response curves to different cold temperatures and exposure durations are lacking. We used a meta-analysis approach using data from literature to investigate the effect of cold stress in the maize leaf. We constructed response curves to temperature and exposure durations for 18 key parameters related to leaf growth, photosynthesis, oxidative stress, antioxidants, and the phytohormone ABA. To determine their relevance for cold tolerance, we compared cold tolerant Flint and cold sensitive Dent lines. Treatment temperatures ranged from -20°C to 20°C for cold and from 12°C to 30°C for control and exposure duration from 3 min to 60 days. We found interacting effects of temperature and exposure durations on different response parameters. The strongest difference between Flint and Dent was observed for electrolyte leakage (EL). Our results show that the commonly used 4°C for cold and 25°C for control with medium cold exposure (1-7 days) induces a 50% decrease in shoot dry weight and leaf area and that EL is an easy and reliable indicator for cold tolerance studies.

Elevated CO2 mitigates the impact of drought stress by upregulating glucosinolate metabolism in Arabidopsis thaliana.

Elevated CO2 (eCO2 ) reduces the impact of drought, but the mechanisms underlying this effect remain unclear. Therefore, we used a multidisciplinary approach to investigate the interaction of drought and eCO2 in Arabidopsis thaliana leaves. Transcriptome and subsequent metabolite analyses identified a strong induction of the aliphatic glucosinolate (GL) biosynthesis as a main effect of eCO2 in drought-stressed leaves. Transcriptome results highlighted the upregulation of ABI5 and downregulation of WRKY63 transcription factors (TF), known to enhance and inhibit the expression of genes regulating aliphatic GL biosynthesis (e.g., MYB28 and 29 TFs), respectively. In addition, eCO2 positively regulated aliphatic GL biosynthesis by MYB28/29 and increasing the accumulation of GL precursors. To test the role of GLs in the stress-mitigating effect of eCO2 , we investigated the effect of genetic perturbations of the GL biosynthesis. Overexpression of MYB28, 29 and 76 improved drought tolerance by inducing stomatal closure and maintaining plant turgor, whereas loss of cyp79f genes reduced the stress-mitigating effect of eCO2 and decreased drought tolerance. Overall, the crucial role of GL metabolism in drought stress mitigation by eCO2 could be a beneficial trait to overcome future climate challenges.

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.

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.

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.

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.

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.

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.