Naila Ali

Abiotic stresses are major constraints to sustainable agriculture. Among this salinity is a critical abiotic stress that severely affects crop productivity in arid and semi-arid regions. It impaired physiological and biochemical functions of plants. It also affects nutrient uptake and causes ionic disbalance. The main aim of this study was to evaluate the effectiveness of four selected exogenously applied amino acids (methionine, tryptophan, glycine betaine, and lysine) in mitigating salt stress and improving physiological performance of maize. Although amino acids are widely used as bio-stimulants but comparative evidence on their parameter specific effects under salinity is limited. The current study has been designed to investigate the effect of different concentrations (0, 25, 75, 100 ppm) of each amino acid in alleviating the effect of salt stress (120 mM NaCl) in Zea mays L. plants. Two factorial (amino acid treatments & salt stress) completely randomized design pot experiment with three replicates was conducted in control conditions. Salt stress reduced the morpho-physiological parameters along with antioxidant activities in Z. mays plants. Conversely, the applications of amino acids increased the growth parameters. Maximum shoot length and biomass were noted under the application of lysine. While maximum increase in root length, number of leaves and biomass of roots was observed under the application of glycine betaine, methionine, and tryptophan, respectively. Photosynthetic pigments were maximized under the influence of glycine betaine. Amino acids also triggered antioxidant activity and increased the production of metabolites. Like, total phenolics, total soluble proteins (TSP) and superoxide dismutase (SOD) were maximized by the application of glycine betaine. Similarly, catalase (CAT), peroxidase (POD) and flavonoids were maximized by the application of tryptophan, and total free amino acids (TFA) were maximized under the effect of methionine application. With increase in concentration of amino acids the studied parameters were also increased gradually. It is concluded that specific amino acids target distinct biochemical pathways to exhibit potential to induce tolerance against saline stress. These findings highlight the potential of amino acids, as bio-stimulants to enhance salt stress tolerance in maize. This indicates a role in boosting the plant’s antioxidant defense system under salt stress. However, validation under field conditions will be crucial to clarify molecular mechanisms to optimize the role of amino acids in sustainable crop production.

Alkaline stress exacerbates ionic toxicity, leading to a decline in plant growth and yield. Lagenaria siceraria (Molina) Stndl., commonly known as squash, an annual plant belonging to the Cucurbitaceae family, is sensitive to alkalinity because of its impact on physiological growth and yield of plant. However, studies on the utilization of plant growth regulators to alleviate alkali stress in Lagenaria siceraria is scarce. In the present study, a pot experiment was conducted to evaluate the impact of foliar application of NAA (0, 50, 75, or 100 ppm) on the growth, yield, and biochemical parameters of L. siceraria under both normal and alkaline stress conditions (0 and 40 mM). The findings revealed that alkaline stress significantly diminished plant growth, biomass, and leaf and fruit counts, whereas NAA application amplified all growth and yield characteristics under both stressful and normal conditions. Additionally, compared with salt stress alone, alkaline stress markedly decreased the levels of photosynthetic pigments; however, 75% NAA application resulted in 43% increase in Chl a, 53% increase in Chl b, and 66% increase in carotenoids. Moreover, there was a notable increase in the primary and secondary metabolites of plants treated with NAA, including a 27% increase in total soluble proteins (TSP), a 38% increase in total free amino acids (TFA), and a 28% and 27% increase in total phenolic and flavonoid contents, respectively, in comparison with the plants subjected only to stress. To further explore the impact of NAA on biochemical parameters of L. siceraria, antioxidant enzymes like catalase (CAT) and peroxidase (POD) activities were assessed. The results indicated that alkali stress increased enzyme activities, which were further increased under the influence of foliar-applied NAA as compared to the plants exposed solely to stress. These findings underscore the beneficial role of exogenous NAA application in mitigating the adverse effects of alkali stress on L. siceraria.

Environmental and anthropogenic activities are pushing the earth towards warmer years, which is reducing agricultural land and causing water scarcity. It is well documented that sunflower (being drought tolerant) crops can be grown under water deficit conditions with some additional supportive priming applications to compensate for drought-induced challenges. However, finding the most efficient and eco-friendly priming tools is always a top priority among researchers to improve plant growth, adaptive traits, and productivity. In this study, an experiment was performed on oil-producing crops (sunflower) using seed magnetic treatment. The seeds were subjected to 0.1, 0.2, and 0.3 Tesla for 20 min, respectively. Plants were exposed to water limitation (100 and 50%) after 30 days of germination. Sunflower showed its tolerance to water limitation by maintaining the majority of growth parameters, nutritive value, metabolizable energy, and higher proline content. Nevertheless, a reduction in the achene number per capitulum, capitulum weight, chlorophyll, catalase activity, unsaturated to saturated fatty acids, anthocyanin, and hydroxyl derivatives of cinnamic acid supported our hypothesis about the need for some supportive techniques. Better metabolic adjustment and percentage of oil yield were manifested by 0.3 T magnetic seed treatment, which was used for phenolic and fatty acid profiling. To conclude, magnetic treatment of seeds may improve their primary metabolic capacity and antioxidation potential, which in turn may activate their secondary metabolism as evidenced by an excess of gallic acid, quercetin, benzoic acid, curcumin acid, sinapic acid, and chlorogenic acid.

Many European and indigenous cultivars of grapes are grown in Pakistan, however, their interrelationship is indistinct. For the identification of these cultivars ampelographic and genetic characterization were used to analyze the similarities and relatedness of grapevine cultivars. Morphological characterization of grapevine cultivars namely Red Globe, Autumn Royal, Crimson, Thompson, Perlette, Kings Ruby, Sundarkhani included berry morphology, fruit skin color, flesh color, sweetness, compactness, and weight of bunch of each cultivar and all the grapevine cultivars were different from each other morphologically based on the studied characters. Molecular diversity of these cultivars was evaluated using Inter-Simple Sequence Repeat (ISSR) marker. Six primers were evaluated which produced a total number of 84 scored bands ranging from 150bp to 1200bp. The polymorphism information content (PIC) values ranged from 0.233-0.457 and percentage of polymorphism varied with each primer ranging from 83 % to 100 %. All grape cultivars were vegetatively propagated which minimized genetic variation as the source of differences among them during the experimental work and data analysis. Our results indicate that ISSR fingerprints are an efficient method for identification and resolution of genetic diversity between different grape cultivars.

Both protein and starch hydrolysis contribute to the effective mobilization of seed reserves to trigger seed germination. We studied the activities of hydrolytic enzymes in germinating seeds of mung bean (Vigna radiata) exposed to cadmium stress at 0, 25, 50, 75, 100 mg.L-1. Exposure to Cd stress decreased the seed germination rate and early seedling growth traits, including root and shoot length and plant fresh and dry biomass compared to control. The adverse effects of Cd were more prominent in terms of shoot length than root length. Seedling α-amylase and protease activities exhibited significant reductions with increasing Cd dose. We also recorded Cd-induced reduction in total soluble proteins and sugars while the concentration of free amino acids exhibited an increase. Above all, a decrease in the hydrolysis process of reserve carbohydrates, proteins and impaired reserve translocation contributed to the inhibition of seedlings’ germination and early growth traits.