The present research was conducted to assess physiological responses of ‘Malas-e-Saveh’ (Malas) and ‘Shishe-Kab’ (Shishe) pomegranates to water of different salt content and electrical conductivity (1.05, 4.61, and 7.46 dS m-1). Both cultivars showed a reduced trunk length due to salinity. Relative water content and stomatal conductivity of both cultivars were significantly reduced under salt stress, but ion leakage increased. In both cultivars, total chlorophyll (Chl) and carbohydrates decreased with rise in salinity, while proline accumulation increased. With salinity increment, the Chl fluorescence parameters (maximum photochemical efficiency of PSII and effective quantum yield of PSII) declined significantly in both cultivars, with higher reduction observed in Shishe. Generally, more Na+ accumulated in shoots and more Cl- was observed in leaves. Cl- accumulation increased by salinity in leaves of Malas, but it was reduced in Shishe. The K+/Na+ ratio in leaves decreased in both cultivars by salinity increment. Malas was less affected by osmotic effects of NaCl, but it accumulated more Cl- in its leaves. Thus, Malas might be more affected by negative effects of salinity., M. Khayyat, A. Tehranifar, G. H. Davarynejad, M. H. Sayyari-Zahan., and Obsahuje bibliografii
Leaf-specific Farquhar-von Caemmerer-Berry (FvCB) model was fitted to characterize the vertical profile of photosynthetic CO2 response within rice canopy. Leaf-position-specific and canopy average FvCB models were fitted to study a suitable leaf representing photosynthetic parameters at the canopy scale. The results showed that leaf photosynthesis was limited by Rubisco activity or ribulose-1,5-bisphosphate regeneration under field conditions. The maximum rate of carboxylation, maximum rate of electron transport, rate of triose phosphates utilization, and light respiration rate in the FvCB model reached the highest values for the top second leaf and then decreased, while the mesophyll diffusion conductance kept decreased in downward leaves. The integrated photosynthetic CO2-response curves for the top fourth and fifth leaves were appropriate for estimating parameters in the FvCB model at the canopy scale.
Tomato samples were collected from the field of Absheron peninsula in Azerbaijan in order to evaluate the incidence of main Tobamoviruses. According to results of serological and molecular tests, Tomato mosaic virus (ToMV), Tobacco mosaic virus (TMV), and Pepper mild mottle virus (PMMoV) were detected as single and mixed infections (TMV + PMMoV; ToMV + PMMoV) in various tomato samples. It was found that Tobamovirus infection caused an increase in the content of malondialdehyde, alterations in the activities of peroxidase enzymes and quantitative and qualitative changes in their molecular isoforms. A comparison of thylakoid membrane polypeptides from virus-infected leaves indicated a decrease in the content of the thylakoid membrane polypeptides with molecular masses of 123, 55, 47, 33, 28-24, 17, and 15 kD. PSII efficiency and the content of chlorophylls (a and b) were significantly lower in the virus-infected leaves., I. M. Huseynova, S. M. Mirzayeva, N. F. Sultanova, D. R. Aliyeva, N. Sh. Mustafayev, J. A. Aliyev., and Obsahuje bibliografii
Dependence of ATP hydrolysis kinetics by the chloroplast coupling factor (CF1) on medium viscosity was studied at varying temperatures. For samples with oxidized and reduced CF1 γ-subunit, this dependence was shown to be described by Cramers’ relationship k - (η/ηo)-n, where k is the reaction rate constant, η/ηo is the medium/water viscosity ratio, and 0 < n < 1. Transition of the γ-subunit from its reduced to oxidized state was accompanied by increasing n value, which is indicative of increasing friction losses between certain enzyme sections and the solution. The increased medium viscosity produced no effect on the reaction activation energy which appeared to be almost the same for the both enzyme states. The molecular mechanisms responsible for CF1 activity loss in viscous media are discussed., A.N. Malyan., and Obsahuje bibliografii