Humans are facing very serious health threats from food contamination with cadmium (Cd), and Cd uptake by wheat is amongst the main causes of Cd entrance into the food chain. The current study examined the effect of foliar application (0, 1.50, 3.00 and 4.00 mM) of various silicate chemicals (calcium silicate and potassium silicate) on wheat growth and Cd addition by wheat under Cd stress 20 mg kg⁻¹ of soil using CdCl₂. The results revealed that under control conditions, the application of Si improved all the growth, physiological, biochemical and quality attributes by reducing malondialdehyde contents and electrolyte leakage. Under Cd stress, the supplementation of Si conferred a better growth rate, gaseous exchange for metabolic activity and maintained the tissues’ turgor and membranes’ stabilities compared to those obtained under control (without Si). The enzymatic activities (superoxide dismutase, peroxidase and catalase) also show rapid action by the application of Si supplement, which were associated with elevated osmoprotectant contents and antioxidants, having role in antioxidant defense against Cd stress. These results suggested that a 4.50 mM concentration of Si supplement (potassium silicate) works effectively against Cd stress. The given results showed that Si supplement is beneficial for the enhancement of many metabolic activities that takes places in plants during the growth period that proved a feasible approach in controlling the Cd concentration within wheat plants and, ultimately, in humans.

Toxicity of heavy-metals in soil is a major constraint for the production of carrots (Daucus carota L.). Different plant growth regulators are being used to overcome this problem. It has been found that plant growth regulators induce stress tolerance in plants. In this study, the role of exogenously applied plant growth regulator, gibberellic acid (GA₃) was examined in soil grown two carrot cultivars under four different levels of lead (0, 50, 100, and 150 mg/kg) with one level of gibberellic acid (50 ppm). Results showed that Pb stress retarded the plant growth and reduced chlorophyll contents in the leaves of both carrot cultivars. A significant decrease was observed in photosynthetic attributes by Pb addition alone. However, exogenously applied GA₃ ameliorated the plant growth and chlorophyll contents in the leaves of both carrot cultivars under Pb stressed conditions. Moreover, GA₃ also decreased the uptake of Pb concentration in carrot leaves and roots. In addition, GA₃ significantly regulated the phenolic compounds concentration in both carrot cultivars under Pb stress. In this study, cultivar T-29 was found to be more tolerant to Pb stress, however, cultivar Mevarick experienced higher damage regarding plant growth under Pb stress.

Ammonia is a critical hazardous nitrogen metabolic product in aquaculture. Despite trials for its control, ammonia intoxication remains one of the most critical issues to overcome. In this study, we explored the modulatory effect and potential mechanism by which Yucca schidigera extract (YSE) can ameliorate ammonia intoxication-induced adverse effects on tilapia health and metabolism. A total number of 120 Nile tilapia were evenly assigned into four groups with three replicates each. The first group served as normal control group; the second group was exposed to ammonia alone from the beginning of the experiment and for four weeks. The third group was supplied with YSE in water at a dose of 8 mg/L and exposed to ammonia. The fourth group was supplied with YSE only in water at a dose of 8 mg/L. YSE supplementation succeeded in improving water quality by reducing pH and ammonia levels. Moreover, YSE supplementation markedly alleviated chronic ammonia-induced adverse impacts on fish growth by increasing the final body weight (FBW), specific growth rate (SGR), feed intake and protein efficiency ratio (PER) while reducing the feed conversion ratio (FCR) via improvements in food intake, elevation of hepatic insulin-like growth factor (ILGF-1) and suppression of myostatin (MSTN) expression levels with the restoration of lipid reserves and the activation of lipogenic potential in adipose tissue as demonstrated by changes in the circulating metabolite levels. In addition, the levels of hepato-renal injury biomarkers were restored, hepatic lipid peroxidation was inhibited and the levels of hepatic antioxidant biomarkers were enhanced. Therefore, the current study suggests that YSE supplementation exerted an ameliorative role against chronic ammonia-induced oxidative stress and toxic effects due to its free radical-scavenging potential, potent antioxidant activities and anti-inflammatory effects.

Wheat (Triticum aestivum) is an important cereal crop, grown throughout the temperate and in some tropical and sub-tropical zones, at higher elevations. Several biotic and abiotic factors influence the production of wheat. In the present study, two wheat varieties have been subjected to disease severity and resistance analysis against Fusarium equiseti. Disease severity analysis revealed Shafaq-2006 to be more resistant than Sahar-2006. Both varieties were further subjected to the expression analysis of six important defense-related genes by RT-PCR and quantitative real-time PCR. This analysis revealed that PR-1, TLP, Chitinase, and β-1,3-glucanase genes were highly expressed in Shafaq-2006 and possibly play a significant role in its defense mechanism. In addition, biochemical and physiochemical parameters were also studied to further explore the difference between resistant and susceptible varieties. With total proline and protein contents, sugar and chlorophyll contents also increased significantly in resistant variety. Likewise, higher relative water content, total plant length, and the high root–shoot ratio was observed in resistant plants, compared to susceptible wheat plants. These increases in chemical and physiological parameters might be related to the activation of the defense mechanism due to the higher expression of PR genes in the resistant wheat variety. These genes can further be employed for cloning into wheat and other transgenic crops to develop resistance against F. equiseti.

Chlorpyrifos (CP) is a pesticide used extensively in agricultural crops. Residual CP has been found in a variety of soils, vegetables and fruits indicating a serious danger to humans. Therefore, it is necessary to restrict its entry into agricultural products for food safety. A wire-house pot experiment was conducted with maize plants in biochar- and compost-amended soil (at 0.25% and 0.50%, respectively, in weight-by-weight composition) contaminated with 100 and 200 mg kg⁻¹ of CP, respectively. Results indicated toxicity at both CP levels (with 84% growth reduction) at CP 200 mg kg⁻¹. However, application of compost and biochar at the 0.50% level improved the fresh weight (2.8- and 4-fold, respectively). Stimulated superoxide dismutase (SOD) and peroxidase (POX) activities and depressed catalase (CAT) activity were recorded in response to CP contamination and were significantly recovered by the amendments. Both amendments significantly decreased the CP phytoavailability. With biochar, 91% and 76% reduction in the CP concentration in maize shoots and with compost 72% and 68% reduction was recorded, at a 0.50% level in 100 and 200 mg kg⁻¹ contaminated treatments respectively. Compost accelerated the CP degradation in postharvest soil. Therefore, biochar and compost amendments can effectively be used to decrease CP entry in agricultural produce by reducing its phytoavailability.

The increasing market demand for decapods has led to a considerable interest in cultivating decapod species at a larger scale. Following the development of hatchery technologies, most research has focused on the development of formulated feeds for commercially farmed decapods once they enter the juvenile stages. The use of formulated feed for decapods at a commercial scale is still in the early stages. This is probably because of the unique feeding behavior that decapods possess: being robust, slow feeders and bottom dwellers, their feeding preferences change during the transition from pelagic larvae to benthic juveniles as their digestive systems develop and become more complex. The current practice of decapod aquaculture involves the provision of juveniles with food such as natural diet, live feed, and formulated feed. Knowledge of nutrient requirements enables diets to be better formulated. By manipulating the levels of proteins and lipids, a formulated feed can be expected to lead to optimal growth in decapods. At the same time, the pellet’s physical characteristics are important factors to be considered upon formulating commercially farmed decapod feeds, considering the unique feeding behavior of the decapod. However, most published studies on decapod nutrition lack data on the physical characteristics of the feed types. Thus, it is difficult to establish a standard feed formulation that focuses on the physical pellet properties. Moreover, careful consideration must be given to the feeding behavior of species, as decapods are known as bottom feeders and are robust in terms of handling feed. Information on the pellet forms, diet composition, and unique feeding behaviors in commercially farmed decapods is gathered to suggest potential better formulated diets that can optimize growth and reproduction. Thus, the purpose of this review is to summarize the information that has been published to date and to come up with suggestions on ways to improve the feed formulation in decapods that comply with their feeding behavior and nutrient requirements. Further research is needed to explore the potential of the pelleted feed at the adult stage so the decapod can take full advantage of the nutrients present in the pellets.