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.

Leishmaniasis, one of the most neglected tropical diseases (NTDs), is the third most important vector-borne disease worldwide. This disease has a global impact and severity of the infection and is greatest in the Middle East. The agent of infection is a protozoan parasite of the genus, Leishmania, and is generally transmitted by blood-sucking female sandflies. In humans, there are three clinical forms of infection: (1) cutaneous (CL), (2) mucocutaneous (ML), and (3) visceral leishmaniasis (VL). This review aims to discuss the current epidemiological status of leishmaniasis in Saudi Arabia, Iraq, Syria, and Yemen with a consideration of treatment options. The elevated risk of leishmaniasis is influenced by the transmission of the disease across endemic countries into neighboring non-infected regions.

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Agriculture, the main water-consuming factor, faces a global water scarcity crisis. Saline water is an alternative water source, while excess NaCl decreases plant growth and productivity of crops. L-cysteine (Cys) is a promising thiol amino acid in plant growth and development. Flax; Linum usitatissimum L. is an economical plant with low salt tolerance. NaCl salt stress at 50 and 100 mM inhibited the growth parameters, the photosynthetic pigments, total soluble sugars, total phenols, and amino nitrogen in flax plants. Salt stress led to a marked rise in proline and lipid peroxidation and altered the protein profile. Foliar application of cysteine at 0.8 and 1.6 mM mitigates the unfriendly effects of NaCl stress on flax plants. Cysteine enhanced the growth traits, photosynthetic pigments, amino nitrogen, total phenols, and new polypeptides in NaCl-stressed plants. However, cysteine declined the total sugars, proline, the activity of peroxidase, and ascorbate peroxidase. The results confirmed that cysteine had reductant properties. Furthermore, it decreased the NaCl oxidative stress and maintained the stability of membranes by lowering lipid peroxidation. Overall, the redox capacity of L-cysteine is the cause behind its potential counteracting of the adverse effects of NaCl toxicity on the growth of flax 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.