Accumulation and distribution of zinc within Miscanthus x giganteus plants grown on elevated Zn concentrations and their photosynthetic performance were investigated. High concentrations of Zn in soils caused an increase of its concentrations in all plant organs. The bioconcentration factor, bioaccumulation factor, and translocation factor were lower than one indicating that M. x giganteus is an excluder plant species. Excessive Zn induced visible leaf damage, i.e. chlorosis and necrosis, only in the oldest leaves, pointing to Zn accumulation. Elevated amounts of Zn in leaves significantly lowered the photosynthetic rate, transpiration rate, stomatal conductance, intercellular CO2 concentrations, parameters of chlorophyll a fluorescence, and chlorophyll b content. Despite Zn excess in leaves, there was no severe reduction in the maximal quantum yield of PSII photochemistry, indicating a high photosynthetic capacity, high tolerance to elevated Zn concetrations, and ability of M. x giganteus to grow on Zn-contaminated soils., G. Andrejić, G. Gajić, M. Prica, Ž. Dželetović, T. Rakić., and Obsahuje bibliografii
The present study was carried out to assess the role of zinc oxide nanoparticles (ZnO-NPs) in tomato plants on growth, photosynthetic efficiency, and antioxidant system. At 20-d stage of growth, roots of tomato plants were dipped into 0, 2, 4, 8, or 16 mg(ZnO-NPs) L-1 for 15, 30, and 45 min and then seedlings were transplanted in their respective cups and allowed to grow under natural environmental conditions. At 45-d stage of growth, the
ZnO-NPs treatments significantly increased growth, photosynthetic efficiency together with activities of carbonic anhydrase and antioxidant systems in a concentration- and duration-dependent manner. Moreover, the treatment by 8 mg(ZnO-NPs) L-1 for 30 min proved to be the most effective and resulted in maximum activities of antioxidant enzymes, proline accumulation and the photosynthetic rate. We concluded that presence of ZnO-NPs improved the antioxidant systems and speeded up proline accumulation that could provide stability to plants and improved photosynthetic efficiency., M. Faizan, A. Faraz, M. Yusuf, S. T. Khan, S. Hayat., and Obsahuje bibliografii
Zinc is a critical mineral nutrient that protects plant cells from salt-induced cell damage. We tested whether the application of Zn at various concentrations [0, 5, 10, or 20 mg kg-1(soil)] would protect almond (Prunus amygdalus) seedlings subjected to salt stress (0, 30, 60, or 90 mM NaCl). All concentrations of Zn, particularly the application of 10 and 20 mg kg-1, increased the net photosynthetic rate, stomatal conductance, the maximal efficiency of PSII photochemistry, and a proline content in almond seedlings grown under salt stress; 20 mg(Zn) kg-1 was the most effective concentration. The activity of superoxide dismutase showed a significant increase under salinity stress and Zn application. The catalase activity decreased in the salt-treated seedlings, but recovered after the Zn treatment. Our results proved the positive effects of Zn on antioxidant enzyme activity scavenging the reactive oxygen species produced under salt stress., A. Amiri, B. Baninasab, C. Ghobadi, A. H. Khoshgoftarmanesh., and Obsahuje seznam literatury
At the heart of Krishna Sobti’s novel Zindagīnāmā (A book of life, 1979) is a village of the Gujrat district (western Panjab, now Pakistan), in the Chaj Doab. The setting is contained within three bands: the outermost band is the village, where most people are Muslim but which is dominated by Śāhjī’s Hindu Khatri family, and above all by Śāhjī himself, a landowner and moneylender. Inside this band is the havelī (large walled house) owned by Śāhjī, and inside the havelī band is the large room ( baiṭ hak) where the men gather. Inside the havelī band there are also the rooms belonging to the women’s realm. Additionally there are several external settings. The village is connected to the world at large through news of events, recounted or witnessed by characters who come into contact with Śāhjī. The period covered is 1900-1916. The narrative consists chiefly of dialogue between the various characters. The language is a mixed vocabulary of Hindi, Urdu and Panjabi. The novel is highly complex, rich in incident and in its cast of characters: Hindu, Sikh and Muslim. The first distinction to be drawn is between the women’s and the men’s world. The women’s world is one of emotions. The men’s world is political in the broad sense of the word and includes Śāhjī business dealings with Muslim Jat tenants. The gatherings in the baiṭ hak of Śāhjī are well attended, and many of the guests are Muslims. Interests sometimes converge and more often diverge, but Śāhjī always handles the conversation skillfully, diplomatically changing the subject when delicate issues such as the economy, politics and, indirectly, religion are raised. Śāhjī’s work as a mediator should not be seen purely as a way of protecting his personal interests. In reality, by mediating in different areas – economic, political and religious – he keeps the village united, providing cultural cohesion. Nonetheless, in Zindagīnāmā, the economic factor emerges repeatedly as the cause of the future Partition.