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THIS WORK aims at enhancing soybean growth and fatty acid composition of oil yield when grown under salinity by seed priming in AsA. Treatment of 10-day-old soybean seedlings with NaCl at 100 or 200 mM for 11 days significantly lowered K+, K+/Na+ ratio and ascorbate (AsA) and inhibited the activities of catalase (CAT) and ascorbate peroxidase (APX), contrarily elevated Na+, soluble sugars, MDA and H2O2. Meanwhile, total fatty acids were lowered in the yielded oil of mature seeds (115 days after sowing) concurrent with decreases in unsaturated fatty acids but increased saturated fatty acids (particularly palmitic and stearic). Nonetheless, seed priming in AsA improved growth coincided with raised K+, K+/Na+ ratio and AsA as well as CAT and APX activities concomitantly with retractions in the accumulated Na+, osmolytes and oxidative stress indices. Besides, saturated fatty acids were decreased but unsaturated fatty acids were increased synchronized with rises in total pool. This finding suggests the alleviation of salinity by priming in AsA through enhancing osmoprotection and antioxidants in addition to improving oil quality particularly omega fatty acids. [ABSTRACT FROM AUTHOR]

DROUGHT is an abiotic stress that affects agriculture and annually causes major setbacks to agricultural productivity. Silicon (Si), a plentiful component of soil which is found to play a role in the alleviation of plant drought stress in plants. Wheat cultivars Suds 14 and Sakha 95 were subjected to drought stress by withholding water at 11 days after emergence (DAE) and amended with 2 mM Na2SiO3 either as soil or foliar applications. So, the treatments were: control, control + Si (as soil application), control + Si (as foliar spray), drought, drought + Si (as soil application), and drought + Si (as foliar spray). The results revealed that drought negatively affected the growth, morphological characteristics, and some metabolic activities of the two wheat genotypes by decreasing most of the measured parameters compared to their control values. Sakha 95 was found to be more sensitive to drought than Suds 14. Both Si treatments improved the drought tolerance in both cultivars however, soil application was more effective than foliar spray in alleviating drought stress in both wheat genotypes. Suds 14 was the most responsive genotype in terms of the morphological traits such as root length, shoot length, and root: shoot ratio. Furthermore, the Si treatment preserved high levels of fresh and dry weights, maintained membrane stability, prevented pigment degradation, increased the accumulation of total soluble and insoluble sugars, enhanced protein, proline, total amino acids, and glycine betaine contents, and promoted the activity of antioxidant enzymes compared to the stressed non-amended plants. [ABSTRACT FROM AUTHOR]

The present work aims to alleviate the impact of drought on flax by priming seeds in folic acid. Drought was applied in pots after 24 days from sowing, and one set of samples were collected up to the 56th day for the determination of growth parameters, malondialdehyde (MDA), H2O2, ascorbate (AsA) and glutathione (GSH), photosynthetic pigments, proteins, proline, sugars, and the activities of catalase (CAT), ascorbate peroxidase (APX), glutathione reductase (GR), glutathione peroxidase (GPX) and ribulose-1,5-P carboxylase/oxygenase (Rubisco). The other set was collected at seed maturity for measurements of oil yield and fatty acid composition. Drought significantly decreased growth parameters, photosynthetic pigments, proteins, AsA, GSH and the activities of CAT, APX, GR, GPX and Rubisco, but raised MDA and H2O2, soluble sugars and proline concentrations. Seed priming with folic acid alleviated the impact of drought on the tested parameters. Priming raised antioxidant level and lowered oxidative stress indices pointing to an efficient antioxidant system for scavenging of free radicles. As concerns the yield analysis, there was a reduction of the number of capsules and seeds, oil quantity and quality (fatty acid concentrations and composition). Folic acid also mitigated the decreases in the number of both capsules and seeds within capsules as well as the oil and fatty acid contents and composition. Priming resulted in a recovery in the unsaturated fatty acid level causing an improvement of the oil yield quality. The results suggest that folic acid overcame the impact of drought ameliorating the oil yield and its quality features. [ABSTRACT FROM AUTHOR]

Physiological parameters and expression levels of drought related genes were analyzed in early vegetative stage of two bread wheat cultivars (Sids and Gmiza) differ in drought tolerance capacity. Both cultivars were imposed to gradual water depletion started on day 17 till day 32 after sowing. Sids, the more tolerant cultivar to drought showed higher fresh and dry weights than the drought sensitive genotype, Gmiza. Under water stress, Sids had higher membrane stability index (MSI), lower accumulated H 2 O 2 and higher activity of the antioxidant enzymes; catalase (CAT), guaiacol peroxidase (GPX), ascorbate peroxidase (APX) and superoxide dismutase (SOD) than Gmiza. On the other hand, the differential expression patterns of the genes dhn , wcor and dreb were observed due to water deficit intensity according to cultivar’s tolerance to drought. The DNA sequence alignment of dun showed high similarity of about 80–92% identities with other related plants. The most striking overall observed trend was the highly induction in the expression of dun , wcor and dreb in leaves of the tolerant genotype, Sids under severe water stress. [ABSTRACT FROM AUTHOR]