Drought is the main limiting abiotic environmental stress worldwide. Water scarcity restricts the growth, development, and productivity of crops. Wheat (Triticum aestivum L.) is a fundamentally cultivated cereal crop. This study aimed to evaluate the effect of grain-priming with arginine (0.25, 0.5, and 1 mM) on growth performance and some physiological aspects of wheat plants under normal or drought-stressed conditions. Morphological growth parameters, photosynthetic pigments, soluble sugars, free amino acids, proline, total phenols, flavonoids, and proteins profiles were determined. Drought stress lowered plant growth parameters and chlorophyll a and b contents while increasing carotenoids, soluble sugars, free amino acids, proline, total phenols, and flavonoids. Soaking wheat grains with arginine (0.25, 0.5, and 1 mM) improves plant growth and mitigates the harmful effects of drought stress. The most effective treatment to alleviate the effects of drought stress on wheat plants was (1 mM) arginine, that increased root length (48.3%), leaves number (136%), shoot fresh weight (110.5%), root fresh weight (110.8%), root dry weight (107.7%), chlorophyll a (11.4%), chlorophyll b (38.7%), and carotenoids content (41.9%) compared to the corresponding control values. Arginine enhanced the synthesis of soluble sugars, proline, free amino acids, phenols, and flavonoids in wheat plants under normal or stressed conditions. Furthermore, the protein profile varies in response to drought stress and arginine pretreatments. Ultimately, pretreatment with arginine had a powerful potential to face the impacts of drought stress on wheat plants by promoting physiological and metabolic aspects.

Knowledge about the risks of the nanoparticles application on the plant development and human health is still limited. Different concentrations of nano-selenium (0, 20 and 40 ppm) were applied to three different Egyptian groundnut (Arachis hypogaea l.) cultivars; (NC, Gregory and Giza 6) under sandy soil conditions at vegetative growth stage to investigate their effects on yield components, protein profile, fatty acids composition, total antioxidant content and cytotoxicity of yielded seeds. The results indicate that the tested Nano-Selenium (Nano-Se) concentrations improved yield components and seeds oil. However, Nano-Se altered protein signatures as well as fatty acids composition by increasing unsaturated fatty acids and/or decreasing saturated fatty acids as compared with control, the cytotoxicity assessments proved safety of the yield for human health.

The objective of this research was to determine the foliar application of L-ornithine (0.0, 0.30 and 0.60 mM) as a precursor of polyamines, at vegetative stage was on antioxidant defense and growth of drought stressed sugar beet plants grown under clay and sandy soil conditions. Two water irrigation treatments (80% and 40% Field capacity) were carried out on sugar beet plants grown in pots under greenhouse conditions. Water stress resulted in significantly decrement in growth parameters including root diameter, root and shoot weights per plant compared with corresponding control plants. The results showed that drought stress significantly affected most biochemical characteristics of plants. Photosynthetic pigments contents, free amino acids and peroxidase enzyme activity were decreased, while catalase enzyme activity and lipid peroxidation was increased with drought stress. On the other hand, foliar application of L-ornithine effectively alleviated harmful effects caused by drought stress on root length, root and shoot weights of sugar beet plants, especially under sandy soil conditions. The results cleared that ameliorating the negative effects of drought stress through exogenously applied L-ornithine associated with improved photosynthetic pigments, protein profile, lipid peroxidation, antioxidant enzymes; catalase and peroxidase, total soluble sugars and total amino led to increasing drought tolerance of sugar beet plants.

Drought stress is a significant environmental variable affecting wheat growth and development. Plant stress tolerance is intimately related to growth regulators of plants as polyamines. The study assessed the impact of drought (50% water irrigation and 100% water irrigation), priming of grains in putrescine (0.25, 0.5, and 1 mM), and their interactions on the growth, yield, and physiological attributes of wheat plants. Drought conditions declined plant height, fresh and dry weights, leaves and tillers numbers, and flag leaf area. However, applying putrescine, especially at (1 mM), enhanced wheat growth performance in normal or water-deficit conditions. Drought stress decreased spike length (28.6%), number of spikelets (15.6%), number of grains (30.3%), the weight of the spike (23.5%), and the weight of the grains/spike (37.5%). In addition, drought decreased the contents of chlorophyll a, chlorophyll b, free amino acids, and total phenols, while applying putrescine enhanced wheat plant growth performance in normal or drought conditions. Putrescine at (1 mM) achieved the highest increase in plant height (38.8%), root length (50%), leaves number (166%), tillers number (80%), flag leaf area (70.3%), shoot fresh weight (99.4%), shoot dry weight (98.4%), root fresh weight (97.8%), root dry weight (210%) compared to the untreated plants. Moreover, pretreatment with putrescine improved chlorophyll a (13.3%), chlorophyll b (70.3%), carotenoids (61.8%), soluble sugars (49.1%), amino acids (42.7%), phenols (52.4%), number of spikelets (59.3%), number of grains (81.1%), and weight of spike (45.4%). Moreover, variations in the protein profile of wheat plants were due to drought conditions and putrescine application. In conclusion, priming wheat grains with putrescine effectively induces protective mechanisms against water stress and improves wheat plants’ physiological attributes and yield components.

Plants are often exposed to non-ideal conditions during their growth. The toxicity of heavy metals as abiotic stressors is a significant concern due to their harmful effects on plants. Glycine betaine (GB) is a potent compatible solute that helps plants resist abiotic stresses and plays a crucial role in alleviating them. This study aimed to determine the effective role of glycine betaine (0.5 and 1 mM) as a foliar treatment in sugar beet plants to cope with the toxicity of cadmium (50 mg/kg soil) and lead (100 mg/kg soil). The application of lead (Pb) and cadmium (Cd) in cultivation soil noticeably suppressed morphological growth attributes, such as chlorophylls, carotenoids, sugars, and proteins. At the same time, the aforementioned levels of heavy metals significantly increased the levels of non-enzymatic antioxidants (phenolics and proline) and enzymatic antioxidants (peroxidase, superoxide dismutase, polyphenol oxidase, and catalase) in the root and shoot tissues of sugar beet plants. In contrast, the use of glycine betaine as foliar treatment at 0.5 and 1 mM alleviated the adverse impacts of cadmium and lead by promoting the aforementioned attributes. Furthermore, the application of 1 mM GB was more effective in increasing the contents of phenolics in root by approximately 16% and 29%, phenolics in shoot by about 25% and 10%, peroxidase activity by about 82% and 116%, superoxide dismutase activity by about 56% and 47%, polyphenol oxidase activity by about 9% and 36%, catalase activity by about 19% and 25%, in cadmium- and lead-stressed plants, respectively. Additionally, it reduced the levels of proline in sugar beet tissues. Overall, the application of glycine betaine has the efficacy to counteract the adverse impacts of cadmium and lead toxicity on sugar beet plants by enhancing the metabolic indices as well as the non-enzymatic and enzymatic antioxidant activities.