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Primary photochemical reactions and the activities of the antioxidant enzymes chloroplastic superoxide dismutase (SOD), glutathione reductase (GR) and glutathione-S-transferase (GST) were determined in water-stressed pearl millet ( Pennisetum glaucum L. cv. HHB-67) plants sprayed with the thiol compounds dithiothreitol (DTT), thioglycolic acid (TGA) and thiourea (TU) and the thiol modifiers 5,5′-dithio-bis-2-nitrobenzoic acid (DTNB) and N-ethylmaleimide (NEM) at the earhead emergence stage (47 days after sowing, DAS), together with a control. Sampling was done at 54 and 67 days after sowing. Photosystem I and II (PS I and II) activities (ferricyanide site) were found to increase in plants sprayed with TU, TGA and DTT at both stages (54 and 67 DAS), but a reduction in PS II activity (DCQ Site) compared with the control was caused by NEM (66.66%) and DTNB (27.77%) at 54 DAS. A similar decrease in the activity of PS II (ferricyanide site) was found at 67 DAS for DTNB (55.55%). The chloroplastic SOD activity increased in chloroplasts isolated from leaves sprayed with thiol compounds at both sampling stages, except for NEM at 54 and 67 DAS. The activities of GR and GST in the leaves were higher in thiol-treated plants than in the control at 54 and 67 DAS, while the lowest GR activity was seen for the sulphydryl modifiers (DTNB and NEM) in leaves at 54 DAS. The experimental data suggest an enhancement in the primary photochemistry and antioxidant enzyme activities of water-stressed pearl millet in response to foliar spraying with thiol compounds.

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White wheat is, categorically, more susceptible to pre-harvest sprouting (PHS) than red wheat. Physiological maturity (PM), defined as when the seeds reach their maximum dry weight, is a critical time before harvesting. The objective of this study was to determine a reference level of α-amylase activity and the corresponding Falling Number (FN) value near the time of PM of selected red and white cultivars in the absence of PHS inducing conditions. Twenty-four soft winter wheat genotypes (12 red and 12 white) adapted to Michigan with varying historic levels of susceptibility to PHS were planted in an α-lattice design in two locations from 2008 to 2010. Spikes were collected three days before PM, at PM, and three days post PM. Samples were freeze-dried, threshed, milled and evaluated for α-amylase activity and FN value using high throughput method. Within genotype, clear trends were observed in the reduction of α-amylase activity and the increase of FN value during the physiological maturation. A nonlinear relationship between α-amylase activity and FN value was fit with an r 2 of 0.801. Significant differences were observed for genotype for both α-amylase activity and FN value for all collection time points. No significant differences were found between red and white wheat, categorically, at any of the three time-points in the absence of PHS. The evaluation results provide a critical reference prior to induction of PHS. The α-amylase activity and FN tests show different advantages in analyzing PHS samples as the relationship between α-amylase activity and FN value is not linear over wide-ranging results.

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Acta Biologica Hungarica
Authors: L. M. Jesus, P. R. C. Abreu, Marcela C. Almeida, Lavínia C. Brito, Sheila F. Soares, D. E. De Souza, Luciana C. Bernardo, A. S. Fonseca, and M. Bernardo-Filho

Since ancient times propolis has been employed for many human purposes because to their favourable properties. Blood constituents labeled with technetium-99m (99mTc) have been used in nuclear medicine procedures. Some authors have reported that synthetic or natural drugs can interfere with the labeling of blood constituents with 99mTc. The aim of this work was to evaluate the action of a propolis extract on the labeling of blood elements with 99mTc. Samples of whole blood of male Wistar rats were incubated in sequence with an aqueous propolis extract at different concentrations, stannous chloride and 99mTc, as sodium pertechnetate. Blood samples were centrifuged to separate plasma and blood cells, soluble and insoluble fractions of plasma and blood cells were also separated after precipitation in trichloroacetic acid solution and centrifugation. The radioactivity was counted and the percentage of incorporated radioactivity (%ATI) for each fraction was calculated. The data obtained showed that the aqueous propolis extract used decreased significantly the %ATI in plasma proteins at higher concentration studied. Results suggest that at high concentration the constituents of this extract could alter the labeling of plasma proteins competing with same binding sites of the 99mTc on the plasma proteins or acting as antioxidant compounds.

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