Enhancing systematic tolerance in Bermuda grass (Cynodon dactylon L.) through amplified alkB gene expression and bacterial-driven hydrocarbon degradation.

This study aimed to access the impact of soil polluted with petroleum (5, 10 g petroleum kg-1 soil) on Bermuda grass (Cynodon dactylon L.) with and without applied bacterial inoculants (Arthrobacter oxydans ITRH49 and Pseudomonas sp. MixRI75). Both soil and seed were given bacterial inoculation. The evaluated morphological parameters of Bermuda grass were fresh and dry weight. The results demonstrated that applied bacterial inoculants enhanced 5.4%, 20%, 28% and 6.4%, 21%, and 29% shoot and root fresh/dry weights in Bermuda grass under controlled environment. The biochemical analysis of shoot and root was affected deleteriously by the 10 g petroleum kg-1 soil pollution. Microbial inoculants enhanced the activities of enzymatic (catalase, peroxidase, glutathione reductase, ascorbate peroxidase, superoxide dismutase) and non-enzymatic (ɑ-tocopherols, proline, reduced glutathione, ascorbic acid) antioxidant to mitigate the toxic effects of ROS (H2O2) under hydrocarbon stressed condition. The maximum hydrocarbon degradation (75%) was recorded by Bermuda grass at 5 g petroleum kg-1 soil contamination. Moreover, bacterial persistence and alkane hydroxylase gene (alkB) abundance and expression were observed more in the root interior than in the rhizosphere and shoot interior of Bermuda grass. Subsequently, the microbe used a biological tool to propose that the application of plant growth-promoting bacteria would be the most favorable choice in petroleum hydrocarbon polluted soil to conquer the abiotic stress in plants and the effective removal of polyaromatic hydrocarbons in polluted soil.

Natural sapogenins as potential inhibitors of aquaporins for targeted cancer therapy: computational insights into binding and inhibition mechanism.

Aquaporins (AQPs) are membrane proteins that facilitate the transport of water and other small molecules across biological membranes. AQPs are involved in various physiological processes and pathological conditions, including cancer, making them as potential targets for anticancer therapy. However, the development of selective and effective inhibitors of AQPs remains a challenge. In this study, we explored the possibility of using natural sapogenins, a class of plant-derived aglycones of saponins with diverse biological activities, as potential inhibitors of AQPs. We performed molecular docking, dynamics simulation and binding energy calculation to investigate the binding and inhibition mechanism of 19 sapogenins against 13 AQPs (AQP0-AQP13) that are overexpressed in various cancers. Our results showed that out of 19 sapogenins, 8 (Diosgenin, Gitogenin, Tigogenin, Ruscogenin, Yamogenin, Hecogenin, Sarsasapogenin and Smilagenin) exhibited acceptable drug-like characteristics. These sapogenin also exhibited favourable binding affinities in the range of -7.6 to -13.4 kcal/mol, and interactions within the AQP binding sites. Furthermore, MD simulations provided insights into stability and dynamics of the sapogenin-AQP complexes. Most of the fluctuations in binding pocket were observed for AQP0-Gitogenin and AQP4-Diosgenin. However, remaining protein-ligand complex showed stable root mean square deviation (RMSD) plots, strong hydrogen bonding interactions, stable solvent-accessible surface area (SASA) values and minimum distance to the receptor. These observations suggest that natural sapogenin hold promise as novel inhibitors of AQPs, offering a basis for the development of innovative therapeutic agents for cancer treatment. However, further validation of the identified compounds through experiments is essential for translating these findings into therapeutic applications.Communicated by Ramaswamy H. Sarma.

Network Pharmacology Combined with Molecular Docking, Molecular Dynamics, and In Vitro Experimental Validation Reveals the Therapeutic Potential of Thymus vulgaris L. Essential Oil (Thyme Oil) against Human Breast Cancer.

Breast cancer is a major global health issue for women. Thyme oil, extracted from Thymus vulgaris L., has shown promising anticancer effects. In the present study, we investigated how Thyme oil can influence breast cancer treatment using a multimethod approach. We used network pharmacology to identify the active compounds of Thyme oil, their molecular targets, and the pathways involved in breast cancer. We found that Thyme oil can modulate several key proteins (EGFR, AKT1, ESR1, HSP90AA1, STAT-3, SRC, IL-6, HIF1A, JUN, and BCL2) and pathways (EGFR tyrosine kinase inhibitor resistance, prolactin signaling pathway, HIF-1 signaling pathway, estrogen signaling pathway, ERBB signaling pathway, AGE-RAGE signaling pathway, JAK-STAT signaling pathway, FoxO signaling pathway, and PI3K-AKT signaling pathway) related to breast cancer progression. We then used molecular docking and dynamics to study the interactions and stability of the Thyme oil-compound complexes. We discovered three potent compounds (aromadendrene, α-humulene, and viridiflorene) that can bind strongly to important breast cancer proteins. We also performed in vitro experiments on MCF-7 cells to confirm the cytotoxicity and antiproliferative effects of Thyme oil. We observed that Thyme oil can inhibit cancer cell growth and proliferation at a concentration of 365.37 µg/mL. Overall, our results provide a comprehensive understanding of the pharmacological mechanism of Thyme oil in breast cancer treatment and suggest its potential as a new or adjuvant therapy. Further studies are needed to validate and optimize the therapeutic efficacy of Thyme oil and its active compounds.

Mycorrhized wheat and bean plants tolerate bismuth contaminated soil via improved metal detoxification and antioxidant defense systems.

Contamination of agricultural fields with bismuth (Bi) reduces crop yield and quality. Arbuscular mycorrhizal fungi (AMF) are known to enhance plant growth and crop production, even under stressful conditions such as soil contamination with heavy metals. The objective of this study was to investigate the effect of AMF on the mitigation of Bi-phytotoxicity in wheat (Triticum aestivum) and beans (Phaseolus vulgaris) and to provide a comprehensive evaluation of the physiological and biochemical basis for the growth and development of AMF-induced plants under Bi stress conditions. Wheat and bean were treated by Bi and AMF individually and in combination. Then the physiological and biochemical responses in the shoot and roots of the two crop species were studied. Evident retardations in plant growth and key photosynthesis-related parameters and accumulation of MDA, H2O2, as markers of oxidative stress, were observed in plants subjected to Bi. AMF colonization reduced the uptake and translocation of Bi in the plant organs by enhancing the exudation of polyphenols and organic acids into the rhizospheric soil. Mycorrhized wheat and bean plants were able to attenuate the effects of Bi by improving metal detoxification (phytochelatins, metallothionein, total glutathione, and glutathione-S-transferase activity) and antioxidant defense systems (both enzymatic and non-enzymatic) and maintaining C assimilation and nutrient status. The current results suggest the manipulation of AMF as a powerful approach to alleviate the phytotoxicity of Bi in legumes and grasses.

Relative biochemical and physiological docking of cucumber varieties for supporting innate immunity against Podosphaera xanthii.

Powdery mildew in cucumber is caused by the Podosphaera xanthii. No strategy for improving disease resistance can be successful in the absence of thorough insights into the physiological and biochemical responses of cucumber plants to powdery mildew. Therefore, a field experiment was executed to evaluate five commercial cucumber varieties (V1: Dynasty, V2: Long green, V3:Desi Kheera, V4:Thamin II, V5:Cucumber 363) for their inherent immunity to powdery mildew. Upon inoculating cucumber plants with Podosphaera xanthii, we noted differential responses among the varieties. Compared to other varieties, V1 and V2 showed higher values (P ≤ 0.05) for chlorophyll-a under control and pathogen-attacked plants respectively. The minimum value of anthocyanin content (-53.73%) was recorded in V3 as compared to other varieties post pathogen infection. All pathogen-infected cucumber varieties showed a considerable (P ≤ 0.05) loss in flavonoid content except V2. The maximum destruction for Phenolics under powdery mildew (179%) were recorded in V4, whereas V1 exhibited maximum phenolic content under control conditions. In pathogen-infected plants, the minimum AsA was recorded in V5 as compared to all other varieties. Pathogen invasion impacted significantly (P ≤ 0.05) the activity of superoxide dismutase (SOD). Besides, cucumber plants after pathogen inoculation resulted in a considerable (P ≤ 0.05) increase of peroxidase (POD) activity in V1 (5.02%), V2 (7.5%), and V3 (11%) in contrast to V4. Our results confirmed that cucumber varieties perform differently, which was brought on by distinct metabolic and physiological modifications that have an impact on growth and development. The changes in different attributes were correlated with cucumber resistance against powdery mildew. The results would help us fully harness the potential of these varieties to trigger disease management initiatives and defense responses.

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.

Effect of green synthesized cerium oxide nanoparticles on fungal disease of wheat plants: A field study.

Recently, there has been considerable attention towards the production of environmentally friendly nanoparticles (NPs). In this investigation, the successful synthesis of cerium oxide nanoparticles (CeO2 NPs) was achieved by employing an eco-friendly technique that utilized an extract from the leaves of local plant quinoa (Chenopodium quinoa L.). The synthesized CeO2 NPs were subjected to characterization using state-of-the-art methods. The prepared CeO2 NPs contained a round shape with clusters and have a size of 7-10 nm. To assess how effective CeO2 NPs derived from C. quinoa were against Ustilago tritici, a fungal disease that negatively affects wheat crop globally, a study was performed on two varieties of wheat crop comprised of Arooj (V1) and Akber (V2), cultivated under field conditions. CeO2 NPs were applied foliarly twice to the wheat crop at four different concentrations: T0 (0 mg/L), T1 (50 mg/L), T2 (75 mg/L), and T3 (100 mg/L). The results revealed that the control group (T0) exhibited the highest disease severity index (DSI) with a value of 75% compared to the other concentrations of CeO2 NPs on both varieties. At a concentration of 100 mg/L of CeO2 NPs, the DSI dropped to a minimum of 35% and 37% on both V1 and V2 respectively. These findings indicated that an increase in the concentration of CeO2 NPs has a beneficial impact on disease severity. Similar patterns have also been observed with disease incidence (DI), with the greatest efficacy observed at a concentration of 100 mg/L of CeO2 NPs. Our investigation has shown that CeO2 NPs exhibitd significant antifungal potential against U. tritici which may be a promising strategy to mitigate fungal disease and crop losses globally.

In silico Prediction of Malvaviscus arboreus Metabolites and Green Synthesis of Silver Nanoparticles - Opportunities for Safer Anti-Bacterial and Anti-Cancer Precision Medicine.

Introduction: Biogenic silver nanoparticles (AgNPs) may be a feasible therapeutic option in the research and development towards selectively targeting specific cancers and microbial infections, lending a role in precision medicine. In-silico methods are a viable strategy to aid in drug discovery by identifying lead plant bioactive molecules for further wet lab and animal experiments. Methods: Green synthesis of M-AgNPs was performed using the aqueous extract from the Malvaviscus arboreus leaves, characterized using UV spectroscopy, FTIR, TEM, DLS, and EDS. In addition, Ampicillin conjugated M-AgNPs were also synthesized. The cytotoxic potential of the M-AgNPs was evaluated using the MTT assay on MDA-MB 231, MCF10A, and HCT116 cancer cell lines. The antimicrobial effects were determined using the agar well diffusion assay on methicillin-resistant S. aureus (MRSA) and S. mutans, E. coli, and Klebsiella pneumoniae. Additionally, LC-MS was used to identify the phytometabolites, and in silico techniques were applied to determine the pharmacodynamic and pharmacokinetic profiles of the identified metabolites. Results: Spherical M-AgNPs were successfully biosynthesized with a mean diameter of 21.8 nm and were active on all tested bacteria. Conjugation with ampicillin increased the susceptibility of the bacteria. These antibacterial effects were most predominant in Staphylococcus aureus (p < 0.0001). M-AgNPs had potent cytotoxic activity against the colon cancer cell line (IC50=29.5 µg/mL). In addition, four secondary metabolites were identified, Astragalin, 4-hydroxyphenyl acetic acid, Caffeic acid, and Vernolic acid. In silico studies identified Astragalin as the most active antibacterial and anti-cancer metabolite, binding strongly to the carbonic anhydrase IX enzyme with a comparatively higher number of residual interactions. Discussion: Synthesis of green AgNPs presents a new opportunity in the field of precision medicine, the concept centered on the biochemical properties and biological effects of the functional groups present in the plant metabolites used for reduction and capping. M-AgNPs may be useful in treating colon carcinoma and MRSA infections. Astragalin appears to be the optimal and safe lead for further anti-cancer and anti-microbial drug development.

Proteomic Profiling Reveals Cytotoxic Mechanisms of Action and Adaptive Mechanisms of Resistance in Porphyromonas gingivalis: Treatment with Juglans regia and Melaleuca alternifolia.

The increasing trend in the rise of antibiotic-resistant bacteria pushes research to discover new efficacious antibacterial agents from natural and synthetic sources. Porphyromonas gingivalis is a well-known bacterium commonly known for causing periodontal disease, and it is associated with the pathogenesis of life-changing systemic conditions such as Alzheimer's. Proteomic research can be utilized to test new antibacterial drugs and understand the adaptive resistive mechanisms of bacteria; hence, it is important in the drug discovery process. The current study focuses on identifying the antibacterial effects of Juglans regia (JR) and Melaleuca alternifolia (MA) on P. gingivalis and uses proteomics to identify modes of action while exploring its adaptive mechanisms. JR and MA extracts were tested for antibacterial efficacy using the agar well diffusion assay. A proteomic study was conducted identifying upregulated and downregulated proteins compared to control by 2D-DIGE analysis, and proteins were identified using MADLI-TOF/MS. The bacterial inhibition for JR was 20.14 ± 0.2, and that for MA was 19.72 ± 0.5 mm. Out of 88 differentially expressed proteins, there were 17 common differentially expressed proteins: 10 were upregulated and 7 were downregulated in both treatments. Among the upregulated proteins were Arginine-tRNA ligase, ATP-dependent Clp protease proteolytic, and flavodoxins. In contrast, down-regulated proteins were ATP synthase subunit alpha and quinone, among others, which are known antibacterial targets. STRING analysis indicated a strong network of interactions between differentially expressed proteins, mainly involved in protein translation, post-translational modification, energy production, metabolic pathways, and protein repair and degradation. Both extracts were equi-efficacious at inhibiting P. gingivalis and displayed some overlapping proteomic profiles. However, the MR extract had a greater fold change in its profile than the JA extract. Downregulated proteins indicated similarity in the mode of action, and upregulated proteins appear to be related to adaptive mechanisms important in promoting repair, growth, survival, virulence, and resistance. Hence, both extracts may be useful in preventing P. gingivalis-associated conditions. Furthermore, our results may be helpful to researchers in identifying new antibiotics which may offset these mechanisms of resistance.

Cd uptake and translocation by camelthorn (Alhagi maurorum Medik): a promising approach for phytoremediation of Cd-contaminated soils.

Camelthorn (Alhagi maurorum Medik) is a desert plant that can withstand a variety of abiotic challenges, including water stress and harsh weather, making it potentially useful for cleaning cadmium (Cd) from contaminated soils. The current study aims to determine the degree of plant tolerance to Cd toxicity and the possibility of using it in the phytoremediation of Cd-contaminated soils. Camelthorn plants were cultivated in soil polluted with Cd at doses of 0, 25, 50, 100, and 200 mg kg-1. The growth, nutrient uptake, Cd concentrations, and some biochemical compounds were determined to study the response of camelthorn plants to Cd stress. Exposure of camelthorn plants to 200 mg kg-1 of Cd inhabited the synthesis of leaf-chlorophyll by 49% compared to the control and reduced the concentrations of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), iron (Fe), and zinc (Zn) by 43, 36, 43, 50, 67, and 36%, respectively. Camelthorn plants can tolerate up to 11 mg kg-1 of available soil Cd, 65 mg kg-1 in the root, and 22 mg kg-1 in the shoot before experiencing Cd toxicity. Camelthorn plants increased the levels of carbohydrates, total phenols, and proline compounds that were used in the scavenging of reactive oxygen species (ROS). Moreover, the plants increased the activity of antioxidant enzymes, i.e., superoxide dismutase (SOD) and peroxidase (POD), to mitigate the oxidative stress caused by Cd toxicity. The root-shoot transfer (TF) of Cd varied between 0.27 to 0.48, while the bioaccumulation factor (BAF) varied between 1.2 and 2.32. Camelthorn plants have a BAF value higher than 1 and a TF value lower than 1. Camelthorn plants accumulate Cd in the roots with low root-shoot transfer and are suitable for phytostabilization technology. Camelthorn plants have a potent antioxidant defense against the toxicity of Cd, and this finding is a good tool in the remediation of Cd-contaminated soil.

The impact of chromium toxicity on the yield and quality of rice grains produced under ambient and elevated levels of CO2.

Rice is a highly valuable crop consumed all over the world. Soil pollution, more specifically chromium (Cr), decreases rice yield and quality. Future climate CO2 (eCO2) is known to affect the growth and yield of crops as well as the quality parameters associated with human health. However, the detailed physiological and biochemical responses induced by Cr in rice grains produced under eCO2 have not been deeply studied. Cr (200 and 400 mg Cr6+/Kg soil) inhibited rice yield and photosynthesis in Sakha 106, but to less extend in Giza 181 rice cultivar. Elevated CO2 reduced Cr accumulation and, consequently, recovered the negative impact of the higher Cr dose, mainly in Sakha 106. This could be explained by improved photosynthesis which was consistent with increased carbohydrate level and metabolism (starch synthases and amylase). Moreover, these increases provided a route for the biosynthesis of organic, amino and fatty acids. At grain quality level, eCO2 differentially mitigated Cr stress-induced reductions in minerals (e.g., P, Mg and Ca), proteins (prolamin, globulin, albumin, glutelin), unsaturated fatty acids (e.g., C20:2 and C24:1) and antioxidants (phenolics and total antioxidant capacity) in both cultivars. This study provided insights into the physiological and biochemical bases of eCO2-induced grain yield and quality of Cr-stressed rice.

Soil structure influences proteins, phenols, and flavonoids of varied medicinal plants in Al Jubail, KSA.

In Al Jubail, Saudi Arabia, 29 medicinal plants have been collected from 15 diverse sites. The goal of this study was to determine how soil texture affected the protein, phenol, and flavonoid contents, and their relationship with the degree of genetic similarity. Most soil samples were loamy sand, except for sites 6 and 10, which were sandy loams. A total of 13 protein bands were shown where four were polymorphic and nine were monomorphic, with hereditary similarities ranging from 1 to 0.86. The results indicated that the protein content ranged from (9.32 µg/gm) in Anabasis setifera to (0.92 µg/gm) in Juncus rigidus. The highest phenol content was found in Halopeplis perfoliata (21.45 mg/gm), whereas the lowest was found in Zygophyllum qatarense 7 (2.133 mg/gm). Salsola imbricate 2 showed the highest flavonoid content (74.97 mg/gm), whereas Juncus rigidus had the lowest (1.43 mg/gm). The concentration varied based on the accession and species. In comparison to the other soils tested, the soil at site 7 had the highest concentrations of calcium (132.5 mEq/L), magnesium (47.5 mEq/L), sodium (52.83 mEq/L), potassium (26.96 mEq/L), chloride (63.00 mEq/L), and electric conductivity (25.9 ds/m). The surveyed accessions were classified into two groups using cluster analysis, principal component analysis, and multivariate heatmap. These findings imply that variations in active compounds that are important for plant tolerance to wild habitats are associated with different soil structures, allowing plants to be used in the pharmaceutical and biomedical industries, as well as selective breeding of accessions with high antioxidant properties.

Nocardiopsis lucentensis and thiourea co-application mitigates arsenic stress through enhanced antioxidant metabolism and lignin accumulation in rice.

Arsenic (As) is a group-1 carcinogenic metalloid that threatens global food safety and security, primarily via its phytotoxicity in the staple crop rice. In the present study, ThioAC, the co-application of thiourea (TU, a non-physiological redox regulator) and N. lucentensis (Act, an As-detoxifying actinobacteria), was evaluated as a low-cost approach for alleviating As(III) toxicity in rice. To this end, we phenotyped rice seedlings subjected to 400 mg kg-1 As(III) with/without TU, Act or ThioAC and analyzed their redox status. Under As-stress conditions, ThioAC treatment stabilized photosynthetic performance, as indicated by 78 % higher total chlorophyll accumulation and 81 % higher leaf biomass, compared with those of As-stressed plants. Further, ThioAC improved root lignin levels (2.08-fold) by activating the key enzymes of lignin biosynthesis under As-stress. The extent of reduction in total As under ThioAC (36 %) was significantly higher than TU (26 %) and Act (12 %), compared to those of As-alone treatment, indicating their synergistic interaction. The supplementation of TU and Act activated enzymatic and non-enzymatic antioxidant systems, respectively, with a preference for young (TU) and old (Act) leaves. Additionally, ThioAC activated enzymatic antioxidants, specifically GR (∼3-fold), in a leaf-age specific manner and suppressed ROS-producing enzymes to near-control levels. This coincided with 2-fold higher induction of polyphenols and metallothionins in ThioAC-supplemented plants, resulting in improved antioxidant defence against As-stress. Thus, our findings highlighted ThioAC application as a robust, cost-effective ameliorative strategy, for achieving As-stress mitigation in a sustainable manner.

Chitosan nanoparticles support the impact of arbuscular mycorrhizae fungi on growth and sugar metabolism of wheat crop.

Arbuscular mycorrhizae fungi (AMF) symbiosis is an indispensable approach in sustainable agriculture. AMF-plant association is likely to be enhanced by the nanoparticle's application. Herein, the impact of chitosan nanoparticles (CSNPs) on the mycorrhizal colonization in wheat has been investigated. The provoked changes in wheat growth, physiology and metabolism were assessed. CSNPs treatment improved AMF colonization (52 %) by inducing the levels of auxins and strigolactones in roots by 32 and 21 %, respectively besides flavonoids exudation into the rhizosphere (9 %). Such supporting action of CSNPs was associated with improved plant biomass production (21 %) compared to AMF treatment. Both treatments synergistically enhanced the photochemical efficiency of photosystem II and stomatal conductance, therefore the photosynthetic rate was increased. The combined application of CSNPs and AMF enhanced accumulation of glucose, fructose, sucrose, and starch (12, 22, 31 and 13 %, respectively), as well as the activities of sucrose-p-synthase, invertases and starch synthase compared to AMF treatment. The synchronous application of CSNPs and AMF promoted the levels of polyphenols, carotenoids, and tocopherols therefore, improved antioxidant capacity (33 %), in the roots. CSNPs can be applied as an efficient biofertilization strategies to enhance plant growth and fitness, beside improvement of health promoting compounds in wheat.

Correction: Javed et al. The Potential Impact of Smog Spell on Humans' Health Amid COVID-19 Rages. Int. J. Environ. Res. Public Health 2021, 18, 11408.

There was an error in the original publication [...].

Elevated CO2 differentially mitigates chromium (VI) toxicity in two rice cultivars by modulating mineral homeostasis and improving redox status.

Chromium (Cr) contamination reduces crop productivity worldwide. On the other hand, the expected increase in the future CO2 levels (eCO2) would improve plant growth under diverse growth conditions. However, the synergetic effect of eCO2 has not been investigated at both physiological and biochemical levels in Cr-contaminated soil. This study aims to analyze the mitigating effect of eCO2 on Cr VI phytotoxicity in two rice cultivars (Giza 181 and Sakha 106). Plants are exposed to different Cr concentrations (0, 200 and 400 mg Cr/kg Soil) at ambient (aCO2) and eCO2 (410 and 620 ppm, respectively). Unlike the stress parameters (MDA, H2O2 and protein oxidation), growth and photosynthetic reactions significantly dropped with increasing Cr concentration. However, in eCO2 conditions, plants were able to mitigate the Cr stress by inducing antioxidants as well as higher concentrations of phytochelatins to detoxify Cr. Notably, the expression levels of the genes involved in mineral nutrition i.e., OsNRAMP1, OsRT1, OsHMA3, OsLCT1 and iron chelate reductase were upregulated in Cr-stressed Giza 181 plants grown under eCO2. Mainly in Sakha 106, eCO2 induced ascorbate-glutathione (ASC/GSH)-mediated antioxidative defense system. The present study brings the first ever comprehensive assessment of how future eCO2 differentially mitigated Cr toxicity in rice.

ISSR and SCoT for evaluation of hereditary differences of 29 wild plants in Al Jubail Saudi Arabian.

This survey is concerned with the hereditary differences of 29 wild plants collected from fifteen different regions in Al Jubail, Saudi Arabia using two molecular marker systems, viz. inter simple sequence repeat (ISSR) and start codon targeted (SCoT) molecular markers. Ten ISSR and ten SCoT primers amplified a total of 142 and 163 bands with a 87% and 84% polymorphism, respectively. The average number of polymorphic bands for each pair of ISSR and SCoT primers combinations was 12.4 and 13.7, respectively. The highest genetic similarity for ISSR (0.97) and SCoT (0.90) were recognized between Zygophyllum qatarense-22 and Juncus rigidus-23, and between Zygophyllum qatarense-28 and Zygophyllum qatarense-29, whereas the lowest was (0.59) differentiated between Zygophyllum qatarense-6 and Salsola imbricate-18 for ISSR and between Cyperus conglomeratus-7 and Halopeplis perfoliata-14 for SCoT. This considers confirmed the value of molecular techniques such as ISSR and SCoT to assess the hereditary differences among the selected 29 weeds for hereditary preservation and plant enhancement.

Metagenomic analysis of bacterial communities of Wadi Namar Lake, Riyadh, Saudi Arabia.

Wadi Namar lake is a new touristic attraction area in the south of Riyadh. Human activities around the lake may lead to changes in water quality with subsequent changes in microenvironment components including microbial diversity. The current study was designed to assess possible changes in bacterial communities of the water at Wadi Namar Lake. Therefore, water samples were collected from three different locations along the lake: L1 (no human activities, no plants), L2 (no human activity, some plants) and L3 (human activities, municipal wastes and some plants). The total DNA of the samples was extracted and subjected to 16S rDNA sequencing and metagenomic analysis; water pH, electrical conductivity (EC), total dissolved solids (TDS) as well as the concentration of Na+1, K+1, Cl-1 and total N were analysed. Metagenomic analysis showed variations in relative abundance of 17 phyla, 31 families, 43 genera and 19 species of bacteria between the locations. Proteobacteria was the most abundant phylum in all locations; however, its highest abundance was in L1. Planctomycete phylum was highly abundant in L1 and L3, while its abundance in L2 was low. The phyla Acidobacteria, Candidatus Saccharibacteria, Nitrospirae and Chloroflexi were associated with high TDS, EC, K+1 and Cl-1 concentrations in L3; various human activities around this location had possibly affected microbial diversity. Current study results help in recognising the structure of bacterial communities at Wadi Namar Lake in relation to their surroundings for planning to environment protection and future restoration of affected ecosystems.

Interactive influence of elevated CO2 and arbuscular mycorrhizal fungi on sucrose and coumarin metabolism in Ammi majus.

The elevated level of CO2 (eCO2) and arbuscular mycorrhizal fungi (AMF) have been known as successful eco-friendly agents for plant growth and development as well as quality enhancers. The current investigation was designed to study the influence of eCO2 (620 µmol CO2 mol-1 air) and AMF on sucrose and phenylpropanoid metabolism, including coumarins, the most important bioactive metabolite in Ammi majus. eCO2 and AMF were applied, and different parameters have been assessed in A. majus such as changes in mycorrhizal colonization, plant biomass production, photosynthesis, and levels of N, P, and Ca besides the key metabolites and enzymes in sucrose and coumarins metabolic pathways. The present outcomes revealed that eCO2 and AMF individually or combined enhanced the plant biomass and photosynthesis as well as nutrient concentrations. Furthermore, the levels of sucrose, soluble sugars, glucose, fructose, and the activities of some key enzymes in their metabolism besides phenylpropanoids metabolites in shoot and root of A. majus have been enhanced by eCO2 and AMF especially when combined. Moreover, upregulation of sucrose is linked to phenylpropanoids metabolic pathway via upregulation of phenylalanine ammonia-lyase activity suggesting high coumarin biosynthesis. Generally, the synergistic effect of both treatments was noted for most of the investigated parameters compared to the individual effect. It could be concluded that the combined application of eCO2 and AMF affects A. majus global metabolism and induces accumulation of phyto-molecules, coumarin, which might improve its medicinal and pharmacological applications.

Increasing atmospheric CO2 differentially supports arsenite stress mitigating impact of arbuscular mycorrhizal fungi in wheat and soybean plants.

Arbuscular mycorrhizal fungi (AMF) are beneficial for the plant growth under heavy metal stress. Such beneficial effect is improved by elevated CO2 (eCO2). However, the mechanisms by which eCO2 improves AMF symbiotic associations under arsenite (AsIII) toxicity are hardly studied. Herein, we compared these regulatory mechanisms in species from two agronomical important plant families - grasses (wheat) and legumes (soybean). AsIII decreased plant growth (i.e., 53.75 and 60.29% of wheat and soybean, respectively) and photosynthesis. It also increased photorespiration and oxidative injury in both species, but soybean was more sensitive to oxidative stress as indicated by higher H2O2 accumulation and oxidation of protein and lipid. eCO2 significantly improved AMF colonization by increasing auxin levels, which induced high carotenoid cleavage dioxygenase (CCDs) activity, particularly in soybean roots. The improved sugar metabolism in plant shoots by co-application of eCO2 and AsIII allocated more sugars to roots sequentially. Sugar accumulation in plant roots is further induced by AMF, resulting in more C skeletons to produce organic acids, which are effectively exudated into the soil to reduce AsIII uptake. Exposure to eCO2 reduced oxidative damage and this mitigation was stronger in soybean. This could be attributed to a greater reduction in photorespiration as well as a stronger antioxidant and detoxification defence systems. The grass/legume-specificity was supported by principal component analysis, which revealed that soybean was more affected by AsIII stress and more responsive to AMF and eCO2. This study provided a mechanistic understanding of the impact of AMF, eCO2 and their interaction on As-stressed grass and legume plants, allowing better practical strategies to mitigate AsIII phytotoxicity.