The diumal changes in leaf net photosynthetíc rate (P^) in two genotypes of wheat, T. aestivum (6x) cv. Sonalika and T. monococcum (2x) cv. G 1372, were analyzed in relatíon to stomatal (4) and mesophyll (/,J limitations of P^, ribulose-1,5- bisphosphate carboxylase (RuBPC) activity and saccharides content of the leaves. Pti decreased towards the aftemoon. The /„ was mostly contributing to the diumal decline in leaf at ear emergence stage. There was a decrease in activation statě of RuBPC in the aftemoon compared to forenoon. Associated with this a marked accumulation of saccharides in wheat leaf during the day was observed. Both the genotypes showed a more or less similar pattem of diumal changes in these parameters but differed in magnitude.
The effects of substrate-heating on gas exchange and leaf water potential of gerbera {Gerbera jamesonii H. Bolus ex Hook.) cv. Maria grown in rockwool as substráte were studied under a plastic greenhouse. Measurements of net photosynthetic rate (Pn), stomatal conductance to water vapour {g^, leaf to air vapour pressure difference (VPD), and leaf water potential ('P) were made along the day, at different dates, during two winter seasons. and were higher in plants grown with substrate-heating than in control plants. Control plants without substrate-heating showed higher VPD values. T' was generally more negative for the control plants. These differences may be ascribed to differences in root activity and/or root development, which are related to the temperature of the substráte.
Quercetin, rutin and phioridzin inhibited the activity of glyceraldehyde-3-phosphate dehydrogenase (GPD) complex from spinách leaves. At a concentiation of 5 X 10'5 M they decreased the rate of 3-phosphoglycerate (PGA) leduction by 90, 50- 80 and 30-40 % , respectively. The activity of the effectors depended on the tiine of isolation of enzymes and the corresponding level of endogenic phenolic compounds. To estimate the effect of the last factor, the enzj^e preparation was obtained in the presence and in the absence of insoluble polyvinylpyrrolidone (Polyciar AT). Using rutin it was shown that in the absence of endogenic phenols the inhibition of PGA reduction was decreased as compared with the variant without Polyciar AT. The effect of rutin was constant during the day. On the basis of data obtained the flavonoids are supposed to inhibit the Benson-Calvin cycie at its reducing stage; this effect may be cooperative and depend on quantitative and qualitative content of endogenic phenolic compounds.
Diurnal patterns of canopy net photosynthetic rates (jPií), evapotranspiration (£) and
water use efBciency (WŤJE = P^^E) of field grown irrigated wheat (Triticum
aestivum L. cv. WH 147) were studied fi'om tillering to maturity at Haryana
Agricultural University Farm, Hisar, India. Hie maximum photosynthetic rates
(^N, max) increased fi'om tillering to anthesis and declined at a rapid rate thereaňer till
maturity. Relatively high £'mav but low WUE„ax were recorded at tillering, milk ripe
and dough stages of growth. Diumally foUowed die course of photosynthetícaUy
active radiation (PAR) fiom tillering to wateiy ripeness but it declined at high PAR at
latter reproductive stages of growth. E was curvilinearly related to air temperature.
There was a lag of about 2 h between ^N, „lax (12.00 h) and E„,ax (14.00 h) during
the day. WUE was high fi-om 07.30 to 10.00 h, depressed during midday and a
slightly increased fi^om 15.00 to 16.00 h.Diurnal patterns of canopy net photosynthetic rates (jPií), evapotranspiration (£) and water use efBciency (WŤJE = P^^E) of field grown irrigated wheat (Triticum aestivum L. cv. WH 147) were studied fi'om tillering to maturity at Haryana Agricultural University Farm, Hisar, India. Hie maximum photosynthetic rates (^N, max) increased fi'om tillering to anthesis and declined at a rapid rate thereaňer till maturity. Relatively high £'mav but low WUE„ax were recorded at tillering, milk ripe and dough stages of growth. Diumally foUowed die course of photosynthetícaUy active radiation (PAR) fiom tillering to wateiy ripeness but it declined at high PAR at latter reproductive stages of growth. E was curvilinearly related to air temperature. There was a lag of about 2 h between ^N, „lax (12.00 h) and E„,ax (14.00 h) during the day. WUE was high fi-om 07.30 to 10.00 h, depressed during midday and a slightly increased fi^om 15.00 to 16.00 h.
The effects of the diurnal variations in ambient temperature on some C3 and C4 enzymes in the Salsola dendroides and Suaeda altissima species of Chenopodiaceae family were studied during the intensive vegetation period. Activities of phosphoenolpyruvate carboxylase (PEPC) and cytosolic aspartate aminotransferase (AsAT) were shown to decrease in both species in the afternoon and evening. The activity of the mitochondrial AsAT decreased in S. altissima, remained relatively constant in S. dendroides during the day. The activity of alanine aminotransferase was high in the S. dendroides species in the morning and evening and decreased in the S. altissima species by the evening. Glucose-6-phosphate activated PEPC in both species throughout the day. The study of the redox status-regulated C3 enzymes showed temperature-related increases in NADP-glyceraldehyde 3-phosphate dehydrogenase activity in both plants, in fructose-2,6-bisphosphatase activity in the S. altissima species, and in NADP-MDH activity in the S. dendroides species in the afternoon., T. Y. Orujova, S. M. Bayramov, U. A. Gurbanova, H. G. Babayev, M. N. Aliyeva, N. M. Guliyev, Y. M. Feyziyev., and Obsahuje bibliografii
The 24-hour urinary excretion of 6-β-hydroxycortisol (6β-OHC) and the urinary ratio of 6β-hydroxycortisol/cortisol (6β-OHC/UFC) have been proposed as noninvasive probes for human cytochrome P450 3A4 isoform (CYP3A4). In this study, we evaluated within- and between-day variability of 6β-OHC excretion and 6β-OHC/UFC ratio in nine Caucasian men with cardiac disease. Each study participant was asked to collect 24-hour urine specimens during four consecutive days in five standardized time intervals. Concentrations of UFC and 6β-OHC were determined by immunoassay and the high-performance liquid chromatographic (HPLC) method, respectively. The HPLC method was accurate and precise, as indicated by the recovery rate of 96.5-103.3 % and less than 5.2 % and 6.3 % of the coefficient of variation for within-run and between-run assay, respectively. In patients, diurnal variations in UFC and 6β-OHC excretion were parallel. Consequently, 6β-OHC/UFC ratio remained stable during the day. Both, 6β-OHC excretion and 6β-OHC/UFC ratio showed significant relationship between 24-hour value and values measured in corresponding collection periods with best correlations obtained from night interval (22.00-06.00, r = 0.86-0.91). These results indicated that urinary 6β-OHC excretion and 6β-OHC/UFC ratio measured in overnight/morning urine could precisely reflect 24-hour values even in severely ill patients. In addition, a simple and sensitive HPLC method was described for determination of 6β-OHC in urine., S. Mičuda, L. Šišpera, M. Hodač, P. Pařízek, L. Fuksa, E. Brčáková, J. Cerman, J. Cermanová, J. Martínková., and Obsahuje bibliografii a bibliografické odkazy