Assessing the Usefulness of Moringa oleifera Leaf Extract as a Biostimulant to Supplement Synthetic Fertilizers: A Review

Enhancing Wheat Tolerance to Cadmium Stress through Moringa Leaf Extract Foliar Application

Cadmium, a hazardous heavy metal prevalent in plants and soil, poses a significant threat to human health, particularly as approximately 60% of the global population consumes wheat, which can accumulate high levels of Cd through its roots. This uptake leads to the translocation of Cd to the shoots and grains, exacerbating the potential health risks. However, promising results have been observed with the use of moringa leaf extract (MLE) foliar spray in mitigating the adverse effects of Cd stress. The current experiment was conducted to find out the Cd stress tolerance of wheat varieties V1 = Akbar-19 and V2 = Dilkash-2020 under exogenous spray of MLE. The treatments of this study were T0 = 0% MLE + 0 µM Cd, T1 = 3% MLE + 0 µM Cd, T2 = 0% MLE + 400 µM Cd, and T3 = 3% MLE + 400 µM Cd. Cd stress demonstrated a significant reduction in morphological attributes as shoot and root fresh weight (22%), shoot and root dry weight (24.5%), shoot and root length (22.5%), area of leaf and number of leaves 30.5%, and photosynthetic attributes (69.8%) in comparison with control. Exposure of wheat plants to Cd toxicity cause oxidative stress, increased H2O2, and MDA up to 75% while foliar application of MLE reduced the activities of reactive oxygen species (ROS). The activity of catalase (CAT), superoxide dismutase (SOD), peroxidase (POD), and ascorbic acid (AsA) increased up to 81.5% as well as organic osmolytes such as phenolics, total soluble proteins, and total soluble sugars were improved up to 77% by MLE applications under Cd stress. Higher accumulation of ionic contents root Na+ (22%) and Cd (44%) was documented in plants under Cd stress as compared to control, while uptake of root mineral ions Ca2+ and K+ was 35% more in MLE-treated plants. In crux, Cd toxicity significantly declined the growth, photosynthetic, and biochemical parameters while 3% MLE application was found effective in alleviating the Cd toxicity by improving growth and physiological parameters while declining reactive oxygen species and root Na+ as well as Cd uptake in wheat.

Assessing a potential conflict associated with the production of Moringa oleifera in the Limpopo Province of South Africa: A systems thinking approach

The increased movement of humans throughout the world allowed the transportation of several species, such as Moringa oleifera Lam. (moringa), into biomes far away from their native habitation. Native to India, moringa is a versatile, drought-tolerant, and fast-growing tree that is easily adaptable to wide-ranging tropical and sub-tropical conditions around the world. It is used in cosmetics, as food and medicine for humans, livestock feed, crop biostimulant, and green manure. Even though moringa is an alien species to South Africa, its production is increasing, and its numerous uses are recognised by communities. Moringa forms part of a highly complex (social, ecological, and economic) system. This is because it is on the Species Under Surveillance for Possible Eradication or Containment Targets (SUSPECT) list under the National Environmental Management Biodiversity Act (NEM:BA) of South Africa. Listing species that are regarded as beneficial to communities on national regulations can cause conflicts and uncertainties among various stakeholders (i.e., environmental policymakers, farmers, rural communities, and government bodies). In this paper, a systems thinking approach was applied to address complex and conflicting issues linked to the production and overall status (economic, ecological, legal, and social) of moringa in South Africa. The Causal Loop Diagram (CLD) was developed to present a broad insight into the complexity of moringa in South Africa and assist in underscoring the feedback mechanisms within the system. Moreover, the CLD indicated that the position of moringa within the country comprised a variety of interdependent variables of government policies, environment, and society, which are interconnected into a multifaceted system. The potential conflict dimensions and types associated with allocating moringa an impact category within the South African context were identified, and this may serve as a useful tool for facilitating engagements and decision-making processes among stakeholders in resolving the status of moringa in South Africa.

Amino Acids Biostimulants and Protein Hydrolysates in Agricultural Sciences

The effects of different types of biostimulants on crops include improving the visual quality of the final products, stimulating the immune systems of plants, inducing the biosynthesis of plant defensive biomolecules, removing heavy metals from contaminated soil, improving crop performance, reducing leaching, improving root development and seed germination, inducing tolerance to abiotic and biotic stressors, promoting crop establishment and increasing nutrient-use efficiency. Protein hydrolysates are mixtures of polypeptides and free amino acids resulting from enzymatic and chemical hydrolysis of agro-industrial protein by-products obtained from animal or plant origins, and they are able to alleviate environmental stress effects, improve growth, and promote crop productivity. Amino acids involve various advantages such as increased yield and yield components, increased nutrient assimilation and stress tolerance, and improved yield components and quality characteristics. They are generally achieved through chemical or enzymatic protein hydrolysis, with significant capabilities to influence the synthesis and activity of some enzymes, gene expression, and redox-homeostasis. Increased yield, yield components, and crop quality; improved and regulated oxidation-reduction process, photosynthesis, and physiological activities; decreased negative effects of toxic components; and improved anti-fungal activities of plants are just some of the more important benefits of the application of phenols and phenolic biostimulants. The aim of this manuscript is to survey the impacts of amino acids, different types of protein hydrolysates, phenols, and phenolic biostimulants on different plants by presenting case studies and successful paradigms in several horticultural and agricultural crops.

Polysaccharides from South Tunisian Moringa alterniflora Leaves: Characterization, Cytotoxicity, Antioxidant Activity, and Laser Burn Wound Healing in Rats

Phytochemical properties have recently increased the popularity of plant polysaccharides as wound dressing materials. This work aims at studying the structural characteristics of polysaccharides extracted from Moringa leaves (Moringa Leaves Water Soluble Polysaccharide: MLWSP), and its antioxidant activities, cytotoxic effects, and laser burn wound healing effects in rats. This MLWSP was structurally characterized. Results showed 175.21 KDa and 18.6%, respectively, for the molecular weight and the yield of the novel extracted polysaccharide. It is a hetero-polysaccharide containing arabinose, rhamnose, and galactose. XRD suggested a semi-crystalline structure of the studied polymer and FT-IR results revealed a typical polysaccharide structure. It is composed of 50 to 500 µm rocky-shaped units with rough surfaces and it was found to inhibit the proliferation of the human colon (HCT-116) (IC50 = 36 ± 2.5 µg/mL), breast (MCF-7) (IC50 = 48 ± 3.2), and ovary cancers (IC50 = 24 ± 8.1). The MLWSP showed significant antioxidant effects compared to Trolox (CI50 = 0.001 mg/g). Moreover, promising wound healing results were displayed. The effect of MLWSP hydrogel application on laser burn injuries stimulated wound contraction, re-epithelization, and remodeling phases 8 days after treatment. The wound healing potential of MLWSP may be due to its significant antioxidant activity and/or the huge amount of monosaccharide molecules.

Interplay of silymarin and clove fruit extract effectively enhances cadmium stress tolerance in wheat (Triticum aestivum)

Introduction

Osmoprotectant supplementation can be used as a useful approach to enhance plant stress tolerance. However, the effect of silymarin and clove fruit extract (CFE) on wheat plants grown under cadmium (Cd) stress has not been studied.

Methods

Wheat seeds were planted in plastic pots filled with ions-free sand. A ½-strength Hoagland's nutrient solution was used for irrigation. Pots were treated with eight treatments thirteen days after sowing: 1) Control, 2) 0.5 mM silymarin foliar application [silymarin], 3) 2% CFE foliar application [CFE], 4) CFE enriched with silymarin (0.24 g silymarin L-1 of CFE) [CFE-silymarin], 5) Watering wheat seedlings with a nutritious solution of 2 mM Cd [Cd]. 6) Cadmium + silymarin, 7) Cadmium + CFE, and 8) Cadmium + CFE-silymarin. The experimental design was a completely randomized design with nine replicates.

Results and discussion

The Cd stress decreased grain yield, shoot dry weight, leaf area, carotenoids, chlorophylls, stomatal conductance, net photosynthetic rate, transpiration rate, membrane stability index, nitrogen, phosphorus, and potassium content by 66.9, 60.6, 56.7, 23.8, 33.5, 48.1, 41.2, 48.7, 42.5, 24.1, 39.9, and 24.1%, respectively. On the other hand, Cd has an Application of CFE, silymarin, or CEF-silymarin for wheat plants grown under Cd stress, significantly improved all investigated biochemical, morphological, and physiological variables and enhanced the antioxidant enzyme activities. Applying CFE and/or silymarin enhanced plant tolerance to Cd stress more efficiently. Our findings suggest using CFE-silymarin as a meaningful biostimulator for wheat plants to increase wheat plants' tolerance to Cd stress via enhancing various metabolic and physiological processes.

Nontoxic and Naturally Occurring Active Compounds as Potential Inhibitors of Biological Targets in Liriomyza trifolii

In recent years, novel strategies to control insects have been based on protease inhibitors (PIs). In this regard, molecular docking and molecular dynamics simulations have been extensively used to investigate insect gut proteases and the interactions of PIs for the development of resistance against insects. We, herein, report an in silico study of (disodium 5'-inosinate and petunidin 3-glucoside), (calcium 5'-guanylate and chlorogenic acid), chlorogenic acid alone, (kaempferol-3,7-di-O-glucoside with hyperoside and delphinidin 3-glucoside), and (myricetin 3'-glucoside and hyperoside) as potential inhibitors of acetylcholinesterase receptors, actin, α-tubulin, arginine kinase, and histone receptor III subtypes, respectively. The study demonstrated that the inhibitors are capable of forming stable complexes with the corresponding proteins while also showing great potential for inhibitory activity in the proposed protein-inhibitor combinations.