Small-Sized Nanophosphorus Has a Positive Impact on the Performance of Fenugreek Plants under Soil-Water Deficit Stress: A Case Study under Field Conditions.

Phosphorus (P) is an essential macronutrient necessary for plant growth, development, and reproduction. Two field experiments were carried out in 2018/2019 and 2019/2020 on P-deficient soil to evaluate the impact of foliar fertilization with nanophosphorus (nP) on growth, yield, and physio-biochemical indices, as well as trigonelline content of fenugreek plants under deficient irrigation (dI) stress (a deficit of 20 and 40% of crop evapotranspiration; dI-20 and dI-40). The growth and yield traits, leaf integrity (relative water content and membrane stability index), photosynthetic pigment contents, leaf and seed P contents, and stem and leaf anatomical features significantly decreased under dI-20, with greater reductions recorded under dI-40. In contrast, water-use efficiency, osmoprotective compounds, including free amino acids, soluble sugars, proline, and trigonelline, along with antioxidant contents (ascorbate, glutathione, phenolics, and flavonoids) and their activity increased significantly under both dI-20 and dI-40. However, foliar feeding with nano-P considerably increased plant growth and yield traits, leaf integrity, photosynthetic pigments contents, leaf and seed P contents, and anatomical features. Besides, water-use efficiency, osmoprotectant contents, and antioxidant content and activity were further increased under both dI-20 and dI-40. The positive effects were more pronounced with the smaller nP (25 nm) than the larger nP (50 nm). The results of this study backed up the idea of using foliar nourishment with nP, which can be effective in modulating fenugreek plant growth and seed production.

Natural Biostimulant Attenuates Salinity Stress Effects in Chili Pepper by Remodeling Antioxidant, Ion, and Phytohormone Balances, and Augments Gene Expression.

A biostimulant is any microorganism or substance used to enhance the efficiency of nutrition, tolerance to abiotic stress and/or quality traits of crops, depending on its contents from nutrients. Plant biostimulants like honey bee (HB) and silymarin (Sm) are a strategic trend for managing stressed crops by promoting nutritional and hormonal balance, regulating osmotic protectors, antioxidants, and genetic potential, reflecting plant growth and productivity. We applied diluted honey bee (HB) and silymarin-enriched honey bee (HB- Sm) as foliar nourishment to investigate their improving influences on growth, yield, nutritional and hormonal balance, various osmoprotectant levels, different components of antioxidant system, and genetic potential of chili pepper plants grown under NaCl-salinity stress (10 dS m‒1). HB significantly promoted the examined attributes and HB-Sm conferred optimal values, including growth, productivity, K+/Na+ ratio, capsaicin, and Sm contents. The antioxidative defense components were significantly better than those obtained with HB alone. Conversely, levels of oxidative stress markers (superoxide ions and hydrogen peroxide) and parameters related to membrane damage (malondialdehyde level, stability index, ionic leakage, Na+, and Cl- contents) were significantly reduced. HB-Sm significantly affects inactive gene expression, as a natural biostimulator silencing active gene expression. SCoT primers were used as proof in salt-treated or untreated chili pepper plants. There were 41 cDNA amplicons selected by SCoT-primers. Twenty of them were EcDNA amplicons (cDNA-amplicons that enhanced their genes by one or more treatments) representing 49% of all cDNA amplicons, whereas 7 amplicons for ScDNA (whose genes were silenced in one or more treatments) represented 17%, and 14 McDNA (monomorphic cDNA-amplicons with control) amplicons were represented by 34% from all cDNA amplicons. This indicates the high effect of BH-Sm treatments in expression enhancement of some inactive genes and their silenced effect for expression of some active genes, also confirming that cDNA-SCoT markers succeeded in detection of variable gene expression patterns between the untreated and treated plants. In conclusion, HB-Sm as a natural multi-biostimulator can attenuate salt stress effects in chili pepper plants by remodeling the antioxidant defense system and ameliorating plant productivity.

Salinity Effects on Gene Expression, Morphological, and Physio-Biochemical Responses of Stevia rebaudiana Bertoni In Vitro.

Stevia rebaudiana Bertoni is a little bush, which is cultivated on a large scale in many countries for medicinal purposes and used as a natural sweetener in food products. The present work aims to conduct a protocol for stevia propagation in vitro to produce and introduce Stevia rebaudiana plants as a new sweetener crop to Egyptian agriculture. To efficiently maximize its propagation, it is important to study the influence of stress factors on the growth and development of Stevia rebaudiana grown in vitro. Two stevia varieties were investigated (Sugar High A3 and Spanti) against salt stress. Leaves were used as the source of explants for callus initiation, regeneration, multiplication and rooting. Some stress-related traits, i.e., photosynthetic pigments, proline contents, and enzyme activity for peroxidase (POD), polyphenol oxidase (PPO), and malate dehydrogenase (MDH) were studied. Murashig and Skoog (MS) medium was supplemented with four NaCl concentrations: 500, 1000, 2000, and 3000 mgL-1, while a salt-free medium was used as the control. The data revealed that salinity negatively affected all studied characters: the number of surviving calli, regeneration%, shoot length, the number of multiple shoots, number of leaf plantlets-1, number of root plantlets-1, and root length. The data also revealed that Sugar High A3 is more tolerant than Spanti. The total chlorophyll content decreased gradually with increasing NaCl concentration. However, the opposite was true for proline content. Isozyme's fractionation exhibited high levels of variability among the two varieties. Various biochemical parameters associated with salt tolerance were detected in POD. Namely, POD4, POD6, POD 9 at an Rf of 0.34, 0.57, and 0.91 in the Sugar High A3 variety under high salt concentration conditions, as well as POD 10 at an Rf of 0.98 in both varieties under high salt concentrations. In addition, the overexpression of POD 5 and POD 10 at Rf 0.52 and 0.83 was found in both varieties at high NaCl concentrations. Biochemical parameters associated with salt tolerance were detected in PPO (PPO1, PPO2 and PPO4 at an Rf of 0.38, 0.42 and 0.62 in the Sugar High A3 variety under high salt concentrations) and MDH (MDH 3 at an Rf of 0.40 in both varieties at high salt concentrations). Therefore, these could be considered as important biochemical markers associated with salt tolerance and could be applied in stevia breeding programs (marker-assisted selection). This investigation recommends stevia variety Sugar High A3 to be cultivated under salt conditions.

Chemical analysis of aqueous extracts of Origanum majorana and Foeniculum vulgare and their efficacy on Blastocystis spp. cysts.

BACKGROUND: Origanum majorana (O. majorana) and Foeniculum vulgare (F. vulgare) are traditionally used herbs in Egypt for treatment of several diseases including parasitic diseases. The Purpose was to determine the efficacy of O. majorana and F. vulgare aqueous extracts (AEs) on Blastocystis spp. in vitro, and to reveal their phenolic, flavonoids components and antioxidant activities through chemical analysis. METHODS: The Efficacy of both plant AEs on human Peripheral Blood Mononuclear Cells (PBMCs) viability was assessed using MTT assay. Isolated Blastocystis spp. cysts from patients' diarrhea samples were incubated with different concentrations of O. majorana and F. vulgare AEs for different incubation periods (24, 48 and 72 h) in comparison with nitazoxanide (NTZ) as a drug control. The total contents of phenolic and flavonoid compounds in the AEs and their ability to reduce DPPH were assessed. High performance liquid chromatography (HPLC) analysis for quantitative and qualitative determination of the phenolic and flavonoid contents was performed. RESULTS: O. majorana AE at a dose of 400 µg /ml showed efficacy rates of 96% and 100% against Blastocystis parasite after 48 and 72 h, respectively, which nearly equivalent to NTZ at a dose of 500 µg/ml. F. vulgare at a dose of 250 µg/ml showed less efficacy rate of 56.4% after 48 h and increased to 70.7% after 72 h. Both extracts contain high phenolic and flavonoid compounds that possess antioxidant and free radical scavenging activities. CONCLUSION: O. majorana and F. vulgare AEs showed dose and time dependent anti-Blastocystis activity.

Chemical analysis and giardicidal effectiveness of the aqueous extract of Cymbopogon citratus Stapf.

Searching for new effective and safe treatment of Giardia lamblia (G. lamblia) parasite is mandatory. The aim was to evaluate the in vitro and in vivo effectiveness of an aqueous extract prepared from the leaves of Cymbagogon citratus (CcAE) against G. lamblia and to reveal the phenolic and antioxidant properties of CcAE. METHODS: CcAE (25, 50, 100, 200, 400, and 500 µg/ml) was in vitro incubated with G. lamblia trophozoites in comparison with metronidazole (MTZ 10 and 25 µg/ml). Growth inhibition was evaluated after 3, 24, and 48 h of drug exposure. Infected groups of mice were orally treated for 7 days with CcAE at 125, 250, and 500 mg/kg/day/mouse, in comparison with a group treated with 15 mg/kg/day/mouse MTZ for the same period. The total phenolic components (TPC), the total flavonoid components (TFC), the 2,2,diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity, and the high-performance liquid chromatography (HPLC) for quantitative and qualitative phenolic content were chemically estimated. After 24 and 48 h of in vitro incubation, the estimated minimal inhibitory concentrations (MIC) were 500 and 400 µg/ml, respectively, and the concentrations that induced 50% growth inhibition (IC50) were 93.8 and 60.4 µg/ml, respectively (P < 0.001). Mice given 500 mg/kg CcAE showed 100% stool clearance of G. lamblia stages, similar to MTZ-treated control group (P < 0.001). The TPC was 10.7 ± 0.2 mg GAE/g and the TFC was 23.9 ± 0.3 mg quercetin/g, and the estimated IC50 for DPPH free radical scavenging was 16.4 ± 0.1 mg/ml. HPLC revealed the major phenolic components of CcAE to be carnosic acid, p-coumaric acid, cinnamiac acid, quercetin, rutin, and chlorogenic acid. In conclusion, CcAE is significantly effective against G. lamblia in vitro and in vivo, and has considerable phenolic and antioxidant properties.