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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]

Treatment with the recommended field dose of isoproturon to 7-d-old wheat seedlings significantly decreased shoot height, fresh and dry weights during the subsequent 15 days. Meanwhile contents of carotenoids, chlorophylls and anthocyanin as well as activities of δ-aminolevulinate dehydratase (ALA-D), phenylalanine ammonia lyase (PAL) and tyrosine ammonia lyase (TAL) were significantly inhibited. On the other hand, the herbicide significantly increased malondialdehyde (MDA), a naturally occurring product of lipid peroxidation and H2O2, while it significantly decreased the contents of glutathione (GSH) and ascorbic acid (AsA) and reduced the activities of superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX). These findings indicate an induction of a stress status in wheat seedlings following isoproturon treatment. However, exogenous GSH appeared to limit the toxic effects of isoproturon and seemed to overcome this stress status. Most likely, contents of pigment and activities of enzymes were raised to approximate control levels. Moreover, antioxidants were elevated and the oxidative stress indices seemed to be alleviated by GSH application. These results indicate that exogenous GSH enhances enzymatic and nonenzymatic antioxidants to alleviate the effects of isoproturon. [ABSTRACT FROM AUTHOR]