This article demonstrates the influence of the method using application of 100 kg N/ha of nitrogen fertilizer and hybrid types of maize (Zea mays L.) on selected efficiency indicators used for this macroelement. It was shown that in comparison to traditional broadcast fertilization, fertilization in rows or fertilization in rows combined partly with top dressing increased the values of such characteristics as nitrogen uptake and use, percentage of fertilizer nitrogen in the total nitrogen uptake as well as the agricultural and physiological effectiveness of the nitrogen. All the studied nitrogen effectiveness factors for maize (apart from physiological effectiveness) were significantly higher for the stay-green cultivar. In relation to a traditional cv. ES Palazzo, the cv. ES Paroli stay-green was characterised by poorer use of the nitrogen uptake regardless of the nitrogen fertilizer application method, which was visible in the lower values of physiological effectiveness.
The effect of gibberellic acid (GA 3 ) on the carbohydrate accumulation in relation to vegetative growth of Zantedeschia 'Black Magic' plants undergoing transition to flowering was investigated. In response to GA treatment the carbohydrate level increased independently of earlier stimulation of shoot emergence. Under vegetative growth stage the content of reducing sugars of leaf blades was 2.5-fold higher than in control plants, and suggests the stimulation of photosynthetic activity. The changes observed during the flowering, in principle noted in petiole tissues, support the GA-effect on assimilate transport to the sink organs. Moreover, the high level of non-structural carbohydrates in petiole tissues, in particular reducing sugars, can be an effect of photosynthetic activity of these organs and/or essential for osmoregulation and high turgor pressure. The results indicate that apart from the influence on the shoot emergence, the GAs may stimulate the photosynthetic activity from the beginning of shoot growth and are thus responsible for the enhancement of callas flower yield.
Qualitative and quantitative composition of flavonoid and isoflavonoid glycosides as well as free aglycones in lupin seedlings (roots and aerial parts) grown under different light conditions or responding to infection with Pleiochaeta setosa, a fungus causing brown leaf spot, were monitored by liquid chromatography with UV and/or mass spectrometric detection. Both physical and biotic factors affected flavonoid and isoflavonoid levels in lupin tissues. Fungal infection evoked significant increase in the amounts of genistein, 2'-hydroxygenistein, and their prenylated derivatives that are thought to function as lupin phytoalexins. Effect on quantitative changes of glycosylated flavonoids and isoflavonoids in the roots and aerial parts was less significant. Moreover, different light conditions applied during seedling growth caused relative changes of flavonoid and isoflavonoid conjugates composition, especially in the leaves of white lupin plants. The chemical structures of flavonoid and isoflavonoid conjugates present in Lupinus angustifolius were elucidated. In addition to genistein and 2'-hydroxygenistein glycosides, flavonol conjugates were identified in leaves, while the composition of root isoflavonoids was similar to that of L. albus reported earlier.
Ultraviolet-B (UV-B) radiation negatively affects plant cells, causing reactive oxygen species (ROS) to be generated. To study the effects of increased UV-B exposure on antioxidant processes, we exposed germination-stage cucumber seedlings to increased ultraviolet radiation and analyzed hydrogen peroxide content and the activity of superoxide dismutase (SOD), catalase (CAT), guaiacol peroxidase (GPX) and syringaldazine peroxidase (SPX). Enzymatic antioxidant system activity generally increased after UV-B supplementation. Activation of CAT, GPX and SPX in cucumber cotyledons correlated positively with increases in SOD activity and hydrogen peroxide content. The results indicate that ROS accumulated despite higher engagement of the enzymatic antioxidant system, and that elevated UV-B radiation triggered oxidative stress in the cucumber cotyledons.K Ke ey y w wo or rd ds s: : Catalase, guaiacol peroxidase, H 2 O 2 , superoxide dismutase, syringaldazine peroxidase.
The plants have developed several defense mechanisms to counteract pathogens. Among others, it includes activation of antioxidant enzymes like β-glucosidase and guaiacol peroxidase (GPX). These proteins participate in the oxidation of phenolic compounds, contributing to their increased fungitoxicity. The study aimed to analyze changes in the activity of β-glucosidase and GPX in four genotypes of winter oilseed rape (Mendel, Monolit, Polka, line L1425) inoculated with seven isolates: Alternaria brassicicola, Alternaria brassicae, Alternaria alternata (3 strains), Ulocladium chartarum (syn. A. chartarum), and Cladosporium cladosporioides. We noted that the varieties of oilseed rape, tested fungal species, and time of the plant material collection had significant (P < 0.001) effect on the activity of β-glucosidase and GPX per protein and fresh matter content comparing to the control group. A. brassicicola caused the highest mean increase in β-glucosidase and GPX activity in all examined genotypes, while other pathogens had a lower impact. Significantly lower β-glucosidase activity inoculated by various pathogens was noted between the L 1425 line and other varieties. GPX activity was in the opposite, the lowest activity was recorded in the Mendel variety, and the highest in the L 1425 line. Keywords Oilseed rape • β-glucosidase • Guaiacol peroxidase • Alternaria black spot Communicated by M. Horbowicz.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.