Alleviating chromium-induced oxidative stress in Vigna radiata through exogenous trehalose application: insights into growth, photosynthetic efficiency, mineral nutrient uptake, and reactive oxygen species scavenging enzyme activity enhancement.

Trehalose serves as a crucial osmolyte and plays a significant role in stress tolerance. The influence of exogenously added trehalose (1 and 5 mM) in alleviating the chromium (Cr; 0.5 mM) stress-induced decline in growth, photosynthesis, mineral uptake, antioxidant system and nitrate reductase activity in Vigna radiata was studied. Chromium (Cr) significantly declined shoot height (39.33%), shoot fresh weight (35.54%), shoot dry weight (36.79%), total chlorophylls (50.70%), carotenoids (29.96%), photosynthesis (33.97%), net intercellular CO2 (26.86%), transpiration rate (36.77%), the content of N (35.04%), P (35.77%), K (31.33%), S (23.91%), Mg (32.74%), and Ca (29.67%). However, the application of trehalose considerably alleviated the decline. Application of trehalose at both concentrations significantly reduced hydrogen peroxide accumulation, lipid peroxidation and electrolyte leakage, which were increased due to Cr stress. Application of trehalose significantly mitigated the Cr-induced oxidative damage by up-regulating the activity of reactive oxygen species (ROS) scavenging enzymes, including superoxide dismutase (182.03%), catalase (125.40%), ascorbate peroxidase (72.86%), and glutathione reductase (68.39%). Besides this, applied trehalose proved effective in enhancing ascorbate (24.29%) and reducing glutathione content (34.40%). In addition, also alleviated the decline in ascorbate by Cr stress to significant levels. The activity of nitrate reductase enhanced significantly (28.52%) due to trehalose activity and declined due to Cr stress (34.15%). Exogenous application of trehalose significantly improved the content of osmolytes, including proline, glycine betaine, sugars and total phenols under normal and Cr stress conditions. Furthermore, Trehalose significantly increased the content of key mineral elements and alleviated the decline induced by Cr to considerable levels.

Enhancing salt stress tolerance in wheat (Triticum aestivum) seedlings: insights from trehalose and mannitol.

Salinity stress, an ever-present challenge in agriculture and environmental sciences, poses a formidable hurdle for plant growth and productivity in saline-prone regions worldwide. Therefore, this study aimed to explore the effectiveness of trehalose and mannitol induce salt resistance in wheat seedlings. Wheat grains of the commercial variety Sakha 94 were divided into three groups : a group that was pre-soaked in 10 mM trehalose, another group was soaked in 10 mM mannitol, and the last was soaked in distilled water for 1 hour, then the pre soaked grains cultivated in sandy soil, each treatment was divided into two groups, one of which was irrigated with 150 mM NaCl and the other was irrigated with tap water. The results showed that phenols content in wheat seedlings increased and flavonoids reduced due to salt stress. Trehalose and mannitol cause slight increase in total phenols content while total flavonoids were elevated highy in salt-stressed seedlings. Furthermore, Trehalose or mannitol reduced salt-induced lipid peroxidation. Salt stress increases antioxidant enzyme activities of guaiacol peroxidase (G-POX), ascorbate peroxidase (APX), and catalase (CAT) in wheat seedlings, while polyphenol oxidase (PPO) unchanged. Trehalose and mannitol treatments caused an increase in APX, and CAT activities, whereas G-POX not altered but PPO activity were decreased under salt stress conditions. Molecular docking confirmed the interaction of Trehalose or mannitol with peroxidase and ascorbic peroxidase enzymes. Phenyl alanine ammonia layase (PAL) activity was increased in salt-stressed seedlings. We can conclude that pre-soaking of wheat grains in 10 mM trehalose or mannitol improves salinity stress tolerance by enhancing antioxidant defense enzyme and/or phenol biosynthesis, with docking identifying interactions with G-POX, CAT, APX, and PPO.

Effects of silicon nanoparticles and conventional Si amendments on growth and nutrient accumulation by maize (Zea mays L.) grown in saline-sodic soil.

Salinity is one of the major abiotic stresses in arid and semiarid climates which threatens the food security of the world. Present study had been designed to assess the efficacy of different abiogenic sources of silicon (Si) to mitigate the salinity stress on maize crop grown on salt-affected soil. Abiogenic sources of Si including silicic acid (SA), sodium silicate (Na-Si), potassium silicate (K-Si), and nanoparticles of silicon (NPs-Si) were applied in saline-sodic soil. Two consecutive maize crops with different seasons were harvested to evaluate the growth response of maize under salinity stress. Post-harvest soil analysis showed a significant decrease in soil electrical conductivity of soil paste extract (ECe) (-23.0%), sodium adsorption ratio (SAR) (-47.7%) and pH of soil saturated paste (pHs) (-9.5%) by comparing with salt-affected control. Results revealed that the maximum root dry weight was recorded in maize1 by the application of NPs-Si (149.3%) and maize2 (88.6%) over control. The maximum shoot dry weight was observed by the application of NPs-Si in maize1 (42.0%) and maize2 (7.4%) by comparing with control treatment. The physiological parameters like chlorophyll contents (52.5%), photosynthetic rate (84.6%), transpiration (100.2%), stomatal conductance (50.5%), and internal CO2 concentration (61.6%) were increased by NPs-Si in the maize1 crop when compared with the control treatment. The application of an abiogenic source (NPs-Si) of Si significantly increased the concentration of phosphorus (P) in roots (223.4%), shoots (22.3%), and cobs (130.3%) of the first maize crop. The current study concluded that the application of NPs-Si and K-Si improved the plant growth by increasing the availability of nutrients like P and potassium (K), physiological attributes, and by reducing the salts stress and cationic ratios in maize after maize crop rotation..

Effect of soil texture and zinc oxide nanoparticles on growth and accumulation of cadmium by wheat: a life cycle study.

Cadmium (Cd) is getting worldwide attention due to its continuous accumulation in agricultural soils which is due to anthropogenic activities and finally Cd enters in food chain mainly through edible plants. Cadmium free food production on contaminated soils is great challenge which requires some innovative measures for crop production on such soils. The current study evaluated the efficiency of zinc oxide nanoparticles (ZnONPs) (0, 150 and 300 mg/kg) on the growth of wheat in texturally different soils including clay loam (CL), sandy clay loam (SCL), and sandy loam (SL) which were contaminated with were contaminated with 25 mg/kg of Cd before crop growth. Results depicted that doses of ZnONPs and soil textures significantly affected the biological yields, Zn and Cd uptake in wheat plants. The application of 300 mg/kg ZnONPs caused maximum increase in dry weights of shoot (66.6%), roots (58.5%), husk (137.8%) and grains (137.8%) in CL soil. The AB-DTPA extractable Zn was increased while Cd was decreased with doses of NPs depending upon soil textures. The maximum decrease in AB-DTPA extractable Cd was recorded in 300 mg/kg of ZnONPs treatment which was 58.7% in CL, 33.2% in SCL and 12.1% in SL soil as compared to respective controls. Minimum Cd concentrations in roots, shoots, husk and grain were found in 300 mg/kg ZnONPs amended CL soil which was 58%, 76.7%, 58%, and 82.6%, respectively. The minimum bioaccumulation factor (0.14), translocation index (2.46) and health risk index (0.05) was found in CL soil with the highest dose of NPs. The results concluded that use of ZnONPs significantly decreased Cd concentration while increased Zn concentrations in plants depending upon doses of NPs and soil textures.

Polyphenols-Rich Extract of Calotropis procera Alone and in Combination with Trichoderma Culture Filtrate for Biocontrol of Cantaloupe Wilt and Root Rot Fungi.

Fungal diseases have always been a major problem for cantaloupe crops; however, synthetic fungicides are hazardous to humans and the environment. Consequently, a feasible alternative to fungicides without side effects could be by using bio agents and naturally occurring plants with antibacterial potential. This study has achieved a novel procedure for managing wilt and root rot diseases by potentially using Trichoderma sp. culture filtrates in consortium with plant extract of Calotropis procera, Rhizoctonia solani, Fusarium oxysporum, and Pythium ultimum, which were isolated from infected cantaloupe roots with identified root rot symptoms. The antagonistic activity of four Trichoderma isolates and analysis of antibiotics and filtrate enzymes of the most active Trichoderma isolate were determined as well as phytochemical analysis of C. procera plant extract using HPLC-UV. The obtained results showed that all Trichoderma isolates considerably lowered the radial growth of P. ultimum, R. solani, and F. oxysporum in varying degrees. The scanning electron micrographs illustrate the mycoparasitic nature of Trichoderma sp. on F. oxysporum. The phytochemical analysis of C. procera indicated that phenolic contents were the major compounds found in extracts, such as vanillin (46.79%), chlorogenic acid (30.24%), gallic acid (8.06%), and daidzein (3.45%) but including only a low amount of the flavonoid compounds rutin, naringenin, and hesperetin. The Pot experiment's findings showed that cantaloupe was best protected against wilting and root rot diseases when it was treated with both Trichoderma sp. culture filtrates (10%) and C. procera extract of (15 mg/mL), both alone and in combination. This study demonstrates that the application of bio agent Trichoderma spp. filtrate with C. procera phenol extract appears useful for controlling wilting and root rot disease in cantaloupe. This innovative approach could be used as an alternative to chemical fungicide for the control of wilting and rot root diseases.

Alleviating lead-induced phytotoxicity and enhancing the phytoremediation of castor bean (Ricinus communis L.) by glutathione application: new insights into the mechanisms regulating antioxidants, gas exchange and lead uptake.

Heavy metals pollution represents a serious issue for cultivable lands and ultimately threatens the worldwide food security. Lead (Pb) is a menacing metal which induces toxicity in plants and humans. Lead toxicity reduces the photosynthesis in plants, resulting in the reduction of plant growth and biomass. The excessive concentration of Pb in soil accumulates in plants body and enters into food chain, resulting in health hazards in humans. The phytoremediation is eco-friendly and cost-efficient technique to clean up the polluted soils. However, to the best of our Knowledge, there are very few reports addressing the enhancement of the phytoremediation potential of castor bean plants. Therefore, the present study aimed to investigate the potential role of glutathione (GSH), as a promising plant growth regulator, in enhancing the lead stress tolerance and phytoremediation potential of castor bean plants grown under lead stress conditions. The results indicated that Pb stress reduced the growth, biomass, chlorophyll pigments and gas exchange attributes of castor bean plants, causing oxidative damage in plants. Pb stress induced the oxidative stress markers and activities of antioxidant enzymes. On the other hand, the application of GSH reduced oxidative stress markers, but enhanced the growth, biomass, photosynthetic pigments, gas exchange attributes, Pb accumulation and antioxidant enzymes activities of lead-stressed castor bean plants. Both Pb uptake and Pb accumulation were increased by increasing concentrations of Pb in a dose-additive manner. However, at high dose of exogenous GSH (25 mg L-1) further enhancements were recorded in the Pb uptake in shoot by 48% and in root by 46%; Pb accumulation was further enhanced in shoot by 98% and in root by 101% in comparison with the respective control where no GSH was applied. Taken together, the findings revealed the promising role of GSH in enhancing the lead stress tolerance and phytoremediation potential of castor bean (Ricinus communis) plants cultivated in Pb-polluted soils through regulating leaf gas exchange, antioxidants machinery, and metal uptake.

The excessive concentration of Lead (Pb) in soil accumulates in plants body and enters into food chain, resulting in health hazards in humans. Phytoremediation is eco-friendly and cost-efficient technique to clean up the polluted soils. However, to the best of our knowledge, there are very few reports addressing the enhancement of the phytoremediation potential of castor bean plants. Therefore, the novelty of this research is that this research studied the potential role of glutathione (GSH), as a promising plant growth regulator, in enhancing the lead stress tolerance and phytoremediation potential of castor bean plants grown under lead stress conditions. The results indicated that Pb stress reduced the growth, biomass, chlorophyll pigments and gas exchange attributes of castor bean plants, causing oxidative damage in plants. Pb stress induced the oxidative stress markers and activities of antioxidant enzymes. On the other hand, the application of GSH reduced oxidative stress markers, but enhanced the growth, biomass, photosynthetic pigments, gas exchange attributes, Pb accumulation and antioxidant enzymes activities of lead-stressed castor bean plants. Taken together, the findings revealed the promising role of GSH in enhancing the lead stress tolerance and phytoremediation potential of castor bean plants cultivated in lead-polluted soils.

γ-Aminobutyric acid (GABA) mitigates drought and heat stress in sunflower (Helianthus annuus L.) by regulating its physiological, biochemical and molecular pathways.

Drought and heat stress are two dominant abiotic stress factors that often occur simultaneously in nature causing oxidative damage in plants and thus decline in yield. The present study was conducted to examine the γ-aminobutyric acid (GABA)-induced heat and drought tolerance in sunflower through physiological, biochemical and molecular analysis. The results showed that drought and heat stress triggered oxidative stress as revealed by enhanced level in hydrogen peroxide, malondialdehyde and electrolyte leakage. Moreover, the photosynthetic attributes such as photosynthetic rate, stomatal conductance and quantum efficiency declined when subjected to drought and heat stress. In this study, GABA treatment effectively alleviated the drought and heat-induced stress as reflected by significantly higher levels of proline, soluble sugar and total protein content. Besides, the data also revealed the direct relationship between antioxidant enzyme activities (superoxide dismutase, peroxidase, glutathione reductase, monodehydroascorbate peroxidase, ascorbate peroxidase) and the relative expression of genes (Heat Shock Proteins, Dehydrin, Osmotin, Aquaporin, Leaf Embryogenesis Protein), under drought and heat stress. Moreover, a significant increase in gene expression was observed upon GABA treatment with respect to control. This data suggest that GABA-induced drought and heat tolerance in sunflower could involve the improvement in osmolyte metabolism, gene expression and antioxidant enzyme activities and thus a rise in the GABA shunt which in turn provides intermediates during long-term drought and heat stress, thus maintaining homeostasis.

Effect of gibberellic acid and titanium dioxide nanoparticles on growth, antioxidant defense system and mineral nutrient uptake in wheat.

Nanoparticles (NPs), as a novel source of industrial materials, have been extensively used in recent years which ultimately ends up in soils and may cause toxic effects on plants. Gibberellic acid (GA), phytohormone, has ability to minimize abiotic stresses in plants. The role of GA in minimizing titanium dioxide (TiO2) NPs stress in plants is still unknown. In current study, soil was spiked with TiO2 NPs (0, 100, 200, 400, 600 mg/kg) while GA was foliar-sprayed at different concentrations during wheat growth. The findings revealed that TiO2 NPs increased the growth, chlorophyll contents, and nutrient (P, K, Fe, Mn) concentrations in tissues till 400 mg/kg and then decrease was observed at 600 mg/kg level of NPs whereas the values of these parameters were higher compared to control irrespective of NPs levels. The NPs enhanced the antioxidant activities (SOD, POD, CAT, APX) and reduced the oxidative stress (EL, H2O2, MDA) in leaves over the control. Foliar GA further improved the growth, yield, nutrients and antioxidant activities while minimized the oxidative stress compared to respective sole NPs- treatments. The interactive effects of NPs and GA were dose dependent. The results proved that studied doses of TiO2 NPs were not toxic to wheat plants except the highest level (600 mg/kg) used and GA positively affected the yield of wheat under TiO2 NPs application. The GA can be used to improve crop growth in the presence of NPs which, however, needs further investigation at higher doses of TiO2 NPs in various crops.

GABA: A Key Player in Drought Stress Resistance in Plants.

γ-aminobutyric acid (GABA) is a non-protein amino acid involved in various physiological processes; it aids in the protection of plants against abiotic stresses, such as drought, heavy metals, and salinity. GABA tends to have a protective effect against drought stress in plants by increasing osmolytes and leaf turgor and reducing oxidative damage via antioxidant regulation. Guard cell GABA production is essential, as it may provide the benefits of reducing stomatal opening and transpiration and controlling the release of tonoplast-localized anion transporter, thus resulting in increased water-use efficiency and drought tolerance. We summarized a number of scientific reports on the role and mechanism of GABA-induced drought tolerance in plants. We also discussed existing insights regarding GABA's metabolic and signaling functions used to increase plant tolerance to drought stress.

Co-application of titanium nanoparticles and melatonin effectively lowered chromium toxicity in lemon balm (Melissa officinalis L.) through modifying biochemical characteristics.

Chromium (Cr) toxicity can negatively affect plant growth and development, impacting agricultural productivity and posing risks to human health. Metallic nanoparticles (MNPs) such as titanium dioxide (TiO2) and natural growth regulators such as melatonin (MT) become a promising technology to manage heavy metal-contaminated soils and promote safe food production. The present work was conducted to find the effect of foliar application of TiO2 NPs (15 mg L-1) and MT (100 µM) on growth, biochemical attributes, and Cr accumulation in plant tissues of Melissa officinalis L. under Cr toxicity (50 and 100 mg Cr kg-1 soil). The results showed that Cr toxicity led to decreased plant performance, where 100 mg Cr kg-1 soil led to notable decreases in shoot weight (28%), root weight (27%), essential oil (EO) yield (34%), chlorophyll (Chl) a + b (33%), while increased malondialdehyde (MDA, 30%), superoxide dismutase (SOD) activity (51%), and catalase (CAT) activity (122%). The use of TiO2 NPs and MT, particularly their co-application, remarkably reduced Cr toxicity by enhancing plant weight, Chl content, and lowered MDA and antioxidant activity. Total phenolic content (TPC), total flavonoid content (TFC), EO percentage, and rosmarinic acid in plants treated with Cr at 50 mg Cr kg-1 soil and co-application of TiO2 NPs and MT were relatively higher than in other treatments. Under 100 mg Cr kg-1 soil, the synergic effect of TiO2 NPs and MT-enhanced rosmarinic acid content (22%) but lowered Cr accumulation in roots (51%) and shoots (72%). Heat map analysis showed that CAT, SOD, MDA, and EO yield had the maximum variability under Cr, TiO2 NPs, and MT. Exogenous TiO2 NPs and MT can be recommended to modulate Cr toxicity in lemon balm under soil Cr toxicity.

Endophytic Bacillus vallismortis and Bacillus tequilensis bacteria isolated from medicinal plants enhance phosphorus acquisition and fortify Brassica napus L. vegetative growth and metabolic content.

Phosphorus fertilization imposes critical limitations on crop productivity and soil health. The aim of the present work is to explore the potential of two phosphate solubilizing bacteria (PSB) species in phosphorus supplementation of canola (Brassica napus L.). Out of 38 bacterial isolates obtained from nine medicinal plants, two bacterial strains (20P and 28P) were proved as the most potent for the in-vitro tricalcium phosphate solubilization test. These isolates verified their activity toward different enzymes as nitrogenase and alkaline phosphatase. Also, 20P and 28P gave a high amount of indole-3-acetic acid, 34.16 µg/ml and 35.20 µg/ml, respectively, and were positive for siderophores production as they detected moderate affinity for iron chelation. Molecular identification confirmed that strain 20P was Bacillus vallismortis and strain 28P was Bacillus tequilensis. A pot experiment was conducted to study the effect of four different phosphorus concentrations (0%, 50%, 75%, and 100% P) each alone and/or in combination with B. vallismortis, B. tequilensis, or both bacterial isolates on the vegetative growth and some physiological parameters of canola. The combined treatment of 50% phosphorus + (B. vallismortis + B. tequilensis) was generally the most effective with respect to shoot height, shoot dry mass, leaf area, photosynthetic pigment fractions, total sugar content, and accumulated NPK content. In contrast, the rhizosphere pH reached the minimum value under the same treatment. These findings highlighted the potential use of PSB (B. vallismortis and B. tequilensis) along with phosphorus fertilization as a safe sustainable tactic.

Effects of agro based organic amendments on growth and cadmium uptake in wheat and rice crops irrigated with raw city effluents: Three years field study.

Cadmium (Cd) accumulates in the vegetative tissues of rice and wheat crops, posing a serious threat in the food chain. A long-term field experiment was conducted to investigate the effects of rice husk biochar (RHB), farm manure (FM), press mud (PrM), and poultry manure (PM) on the growth, yield, and economics of wheat and rice crops grown with sewage water. The results showed that RHB increased wheat plant height (27%, 66%, 70%), spike-length (33%, 99%, 56%), straw yield (21%, 51%, 49%), and grain yield (42%, 63%, 65%) in year-1, year-2, and year-3, than respective controls. For rice crop, RHB showed the maximum increase in plant height (64%, 92%, 96%), spike length (55%, 95%, 90%), straw yield (34%, 53%, 55%), and grain yield (46%, 66%, 69%) each year (2019-2021), compared to their respective controls. The Cd immobilization was increased by the application of RHB while other treatments followed FM > PrM > PM > control in each year of wheat and rice crops. For year-1, benefit-cost ratio remained maximum with the application of FM while for the 2nd and 3rd years in sequence, RHB proved more economical than other treatments and consistently produced wheat and rice with lower Cd concentration than FM, PrM, and PM in grains. This long-term experiment suggested that the application of organic amendments consistently increased biomass of rice and wheat and decreased the Cd concentration in tissues. The RHB remained more effective compared with FM, PrM, and PM in terms of yield, low Cd accumulation and economics of rice and wheat crops.

Residual efficiency of iron-nanoparticles and different iron sources on growth, and antioxidants in maize plants under salts stress: life cycle study.

Exogenous application of iron (Fe) may alleviate salinity stress in plants growing in saline soils. This comparative study evaluated the comparative residual effects of iron nanoparticles (FNp) with two other Fe sources including iron-sulphate (FS) and iron-chelate (FC) on maize (Zea mays L.) crop grown under salt stress. All three Fe sources were applied at the rate of 15 and 25 mg/kg of soil before the sowing of wheat (an earlier crop; following the sequence of crop rotation) and no further Fe amendments were added later for the maize crop. Results revealed that FNp application at 25 mg/kg (FNp-2) substantially increased maize height, root length, root dry weight, shoot dry weight, and grain weightby 80.7%, 111.1%, 45.7%, 59.5%, and 77.2% respectively, as compared to the normal controls; and 62.6%, 81.3%, 65.1%, 78%, and 61.2% as compared to salt-stressed controls, respectively. The FNp-2 treatment gave higher activities of antioxidant enzymes, such as superoxide dismutase, peroxidase, catalase, and ascorbate peroxidase compared to salt stressed control (50.6%, 51%, 48.5%, and 49.2%, respectively). The FNp-2 treatment also produced more photosynthetic pigments and better physiological markers: higher chlorophyll a contents by 49.9%, chlorophyll b contents by 67.2%, carotenoids by 62.5%, total chlorophyll contents by 50.3%, membrane stability index by 59.1%, leaf water relative contents by 60.3% as compared to salt stressed control. The highest Fe and Zn concentrations in maize roots, shoots, and grains were observed in FNp treatment as compared to salts stressed control. Higher application rates of Fe from all the sources also delivered better outcomes in alleviating salinity stress in maize compared to their respective low application rates. The study demonstrated that FNp application alleviated salinity stress, increased nutrient uptake and enhanced the yield of maize grown on saline soils.

Eco-Physiological Responses of Avicennia marina (Forssk.) Vierh. to Trace Metals Pollution via Intensifying Antioxidant and Secondary Metabolite Contents.

Mangrove is one of the most precious ecosystems with the greatest losses due to climate change, human activities, and pollution. The objective of this study is to assess the accumulation and distribution of some trace metals (Cu, Cd, Ni, Pb, and Zn) in sediments and Avicennia marina roots and leaves and to discuss the antioxidant potential of A. marina under metallic pollution stress. Sediments, leaf, and root samples of A. marina were collected from five sites along the Red Sea Coast of Egypt. Several ecological pollution indices, including the geo accumulation index (Igeo), contamination factor (CF), pollution load index (PLI), bioconcentration factor (BCF), and translocation factor (TF), were used to assess the pollution load. Cu, Cd, Ni, Pb, and Zn average concentrations in sediments were 167.4, 0.75, 110.65, 39.79, and 220 µg g-1, respectively, and the average values of these metals in A. marina roots were 44.9, 0.5, 87.96, 39.02, and 54.68 µg g-1, respectively, while in leaves their concentration were 50.46, 0.5572, 88.24, 40.08, and 56.08 µg g-1, respectively. The values of the Igeo, CF, and PLI index indicated that location 1 and 5 are moderate-to-heavily contaminated sites. On the other hand, leaves and roots of A. marina grown in polluted locations 1 and 5 showed high accumulation of malondialdehyde (MDA), low chlorophyll a and chlorophyll b contents concomitant with a decrease in total soluble sugars. High total antioxidant capacity was associated with a significant increase in activity levels of antioxidant enzymes (Catalase, Polyphenol oxidase, Polyphenol peroxidase, and Ascorbic acid oxidase), accumulation of secondary metabolites (total phenols, flavonoids, and tannins), and proline and carotenoids content increase. Overall, the present study suggests that the mangrove habitat of the Egyptian Red Sea coast is under the stress of anthropogenic activities, which necessitates a conservation plan to avoid further contamination and protect the unique biota of this distinctive habitat.

Rice straw based silicon nanoparticles improve morphological and nutrient profile of rice plants under salinity stress by triggering physiological and genetic repair mechanisms.

The agricultural sector is facing numerous challenges worldwide, owing to global climate change and limited resources. Crop production is limited by numerous abiotic constraints. Among them, salinity stress as a combination of osmotic and ionic stress adversely influences the physiological and biochemical processes of the plant. Nanotechnology facilitates the production of crops either directly by eradicating the losses due to challenging environmental conditions or indirectly by improving tolerance against salinity stress. In this study, the protective role of silicon nanoparticles (SiNPs) was determined in two rice genotypes, N-22 and Super-Bas, differing in salinity tolerance. The SiNPs were confirmed through standard material characterization techniques, which showed the production of spherical-shaped crystalline SiNPs with a size in the range of 14.98-23.74 nm, respectively. Salinity stress adversely affected the morphological and physiological parameters of both varieties, with Super-Bas being more affected. Salt stress disturbed the ionic balance by minimizing the uptake of K+ and Ca2+ contents and increased the uptake of Na+ in plants. Exogenous SiNPs alleviated the toxic effects of salt stress and promoted the growth of both N-22 and Super-Bas, chlorophyll contents (16% and 13%), carotenoids (15% and 11%), total soluble protein contents (21% and 18%), and the activities of antioxidant enzymes. Expression analysis from quantitative real-time PCR showed that SiNPs relieved plants from oxidative bursts by triggering the expression of HKT genes. Overall, these findings demonstrate that SiNPs significantly alleviated salinity stress by triggering physiological and genetic repair mechanisms, offering a potential solution for food security.

In vitro efficacy of Boswellia carterii resin extracts formulated as an emulsifiable concentrate against Tetranychus urticae and phytopathogenic fungi.

Contemporary agriculture heavily relies on pesticides for pest eradication and disease management. Consequently, current study was carried out to assess the acaricidal/antifungal efficacy of emulsifiable concentrate (10 % EC) derived from Boswellia carterii (B. carterii) against adult females of Tetranychus urticae (T. urticae), and five fungal pathogens. The meticulous examination of the chemical constitution of the crude extracts derived from the resin of B. carterii was conducted through the employment of the venerable technique known as Gas-Liquid Chromatography (GLC). The formulated petroleum-ether extract (FPEE) and formulated ethyl-acetate extract (FEAE) of B. carterii at a concentration of 10 mg ml-1 exhibited notable antioxidant activity with rates of 62.0 % and 90.8 %, respectively. In vitro, the FEAE exhibited potent inhibition against all the tested phytopathogenic fungi at different concentrations, whereas FPEE showed comparatively less efficacy. Interestingly, at 4000 ppm concentration, FEAE completely ceased the mycelial growth compared with the control. Moreover, following a span of 72 h of intervention, FPEE exhibited a greater degree of toxicity towards mature females of the T. urticae. This was evidenced by the LC50 value of 422.52 parts per million (ppm) for FPEE, which surpassed the LC50 value of 539.50 ppm observed for FEAE. In summary, the present study indicates that B. carterii resin formulated as an emulsifiable concentrate (10 % EC) can offer a natural and effective alternative for integrated pest management, thereby reducing reliance on synthetic pesticides and offering a more environmentally sustainable strategy for pest control.

Response of Moringa oleifera trees to salinity stress conditions in Tabuk region, Kingdom of Saudi Arabia.

Moringa oleifera is an amazing tree with various applications. Salinity is a world major barrier to crop productivity. This study was conducted to investigate salinity and seaweed extract's effect on Moringa oleifera's growth and yields. Measurements were made of growth characteristics, fresh and dried leaf, inflorescence, mature pod and seed weight, and yield per tree, as well as chemical parameters. Seasons had no substantial effect on any of these traits. In terms of seaweed concentrations, the treatment containing 20% seaweed outperformed the treatment containing 0% seaweed in all measurements. Concerning the salinity levels, the maximum level of all studied attributes was at 18.75 mmol/L NaCl, while the level of 70.31 mmol/L NaCl has the lowest values. The interaction between salinity levels and seaweed revealed that T4 (18.75 mmol/L NaCl plus 20 % seaweed) was the highest for all traits and T9 (70.31 mmol/L NaCl plus 0 % seaweed) was the lowest for all traits except for the potassium content. Concerning potassium content, T7 (54.69 mmol/L NaCl plus 0 % seaweed) was the lowest. These findings could help to develop efficient breeding methods for Moringa oleifera in the future.

Combined effects of zinc oxide nanoparticles and melatonin on wheat growth, chlorophyll contents, cadmium (Cd) and zinc uptake under Cd stress.

Zinc oxide nanoparticles (ZnONPs) and melatonin (MT) have been known to regulate heavy metal toxicities in plants in some studies, the effect of their combined use on cadmium (Cd) uptake by wheat (Triticum aestivum L.) and underlying mechanisms is largely unknown. Thus, plant growth, uptake and translocation of Cd mediated by soil applied ZnONPs and foliar applied MT were investigated in wheat grown in Cd polluted soil under ambient conditions. The results depicted that ZnONPs stimulated the growth, chlorophyll contents, and yield of wheat in a dose additive way and this effect was further increased with foliar application of MT. 100 mg/kg of ZnONPs alone enhanced the grain yield by 60.5 % and this increase was about 177.5 % under combined ZnONPs and 100 µM MT treatment. ZnONPs treatments decreased Cd concentration whereas increased zinc (Zn) concentrations in shoots, roots, husks and grains and the effect was further increased with exogenous MT combined with NPs in a dose-additive way. 50 and 100 mg/kg ZnONPs treatments alone decreased grain Cd by 6.5 %, and 20 % and increased the Zn concentration by 20.1 % and 24 % than control. 100 mg/kg ZnONPs +100 µM MT treatment decreased the grain Cd by 63.5 % and increased grain Zn by 51 % than control treatment. Total Cd uptake (tissues biomass × Cd concentration in respective tissues) in shoots, roots, husks and grains increased with ZnONPs alone or combined with MT than control whereas soil post-harvest bioavailable Cd concentration decreased with treatments than control. The Cd reduction in grains was due to increase in biomass and Zn concentration thereby decreasing bioavailable Cd in soil and its accumulation in plants. This study suggested that combined use of ZnONPs and MT may provide new approaches for minimizing Cd and biofortification of Zn in edible parts of plants.

Multivariate characterization of biochemical and physiological attributes of quinoa (Chenopodium quinoa Willd.) genotypes exposed to nickel stress: implications for phytoremediation.

Nickel (Ni) is an essential element for plants; however, excessive uptake of Ni causes phytotoxicity in plants. The phytotoxic effects of Ni on the growth of quinoa and the underlaying mechanisms for Ni tolerance and phytoremediation are unknown. Hence, the present study investigated Ni tolerance and accumulation potential of two quinoa genotypes (Puno and Vikinga). Both genotypes were exposed to Ni (0, 100, 200, 300, and 400 µM) in half-strength Hoagland nutrient solution for three weeks. Results revealed that shoot and root lengths, biomass, stomatal conductance, and chlorophyll contents were decreased with the increase of Ni concentration. Excessive uptake of Ni resulted in the limited uptake of K by root and its translocation to shoot. Ni caused oxidative stress in plants by overproduction of H2O2 leading to lipid peroxidation of cell membranes. Genotype Puno showed greater tolerance to Ni than Vikinga based on tolerance index, lower bioconcentration factor, and translocation factor. Greater tolerance of Puno was mainly attributed to improved physiological responses and amelioration of oxidative stress by induction of antioxidant enzymes such as peroxidase (POD), catalase (CAT), superoxide dismutase (SOD), and ascorbate peroxidase (APX). It was revealed through multivariate analysis that Ni had strong negative correlations with growth and physiological attributes and positive associations with oxidative stress attributes. The study demonstrated genotypic variation in response to varying Ni concentrations and Puno performed better than Vikinga for phytostabilization of Ni-contaminated soils.

The Bio-herbicidal potential of some wild plants with allelopathic effects from Tabuk Region on selected local weed species.

Weeds are considered one of the most serious problems limiting global agricultural production. As a result, chemical herbicides have been extensively used for weed control. However, overuse of synthetic herbicides, has resulted in public concerns over the effect of herbicides on the health of the ecosystems and humans. In the food system, innovative approaches are needed to foster sustainable practices that preserve biodiversity, conserve habitats, and mitigate climate change factors. Thus, alternatives are required to control the weeds. This study aimed to determine the impact of some wild plants' (Citrullus colocynthis, Euphorbia retusa, Retama raetam, Artemisia monosperma, Tamarix gallica, and Artemisia judaica) allelopathic potentials (at rates of 0, 15, 25, 35, and 50 g/L) on seed germination of selected local weeds (Portulaca oleracea, Amaranthus retroflexus, and Chloris barbata) collected from different locations in Tabuk region, Saudi Arabia. GC-MS analysis was used to evaluated the main compounds in the wild plants under study. The experimental design was completely randomized block design (CRBD) with three replicates. According to the results, phytochemical screening of the wild plants using GC-MS analysis showed a wide range of phytochemicals. Amaranthus retroflexus exhibited the highest germination rate in the control group. In addition, applying 5 g/L and 20 g/L of Citrullus colocynthis extracts had no discernible effect on the rate of germination of A. retroflexus seed; however, they were able to reduce the germination rate as compared to the control. As the extract concentration of Artemisia monosperma rose to 20 g/L, the germination rate of A. retroflexus dropped. Neither 35 g L-1 nor 50 g L-1 of A. monosperma extract inhibited the germinate of A. retroflexus. The germination rate of Portulaca oleracea decreased with increasing extract concentration of C. colocynthis. The extract of C. colocynthis at 50 g/L had the lowest rate. The germination rate of Chloris barbata decreased with increasing extract concentration of C. colocynthis. The highest germination rate of C. barbata was observed in control, followed by 5g/L, while no germination was observed at 20, 35, and 50 g/L of C. colocynthis extracts. A. retroflexus's root length shrank when the extract concentration of C. colocynthis rose. A. retroflexus's control sample had the most extended root length, followed by 5 and 20 g/L, respectively. C. colocynthis at 35 and 50 g/L showed no root elongation as this treatment inhibited radicle protrusion. High concentration of d-Glycero-d-galacto-heptose and pentane in C. colocynthis aqueous extract may be the cause of C. colocynthis' ability to inhibit Chloris barbata germination. The entire C. barbata plant length decreased when treated with 5 g/L of C. colocynthis extract. No growth was seen at any of the higher C. colocynthis concentrations (20, 35, and 50 g/L). The present work revealed that cultivating allelopathic crops like the selected studied wild plants from the Tabuk region has a promising future as an antagonistic species in a biological weed control program or combined with integrated weed management in agricultural food production.