Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 5

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
Photosynthetic gas exchange in the leaves of wheat plants growing in a nutrient solution containing 0 or 2 mM silicon (Si) and inoculated with Pyricularia oryzae was investigated. The blast severity, the gas exchange parameters such as net carbon assimilation rate (A), stomatal conductance to water vapor (gs), internal CO₂ concentration (Cᵢ) and transpiration rate (E) and the concentration of pigments (chlorophyll a, chlorophyll b and carotenoids) were determined. The blast severity was reduced by 67.66 % on +Si plants compared with the -Si plants. There were significant increases of 29.3, 17.7 and 45 % for A at 48, 72 and 96 h after inoculation (hai); 26.7 and 49 % for gs at 48 and 96 hai; and 25.2 and 31.4 % for E at 48 and 96 hai, respectively, for +Si inoculated plants when compared with the -Si inoculated plants. The Cᵢ was significantly lower for +Si inoculated plants than for -Si inoculated plants at 48, 72 and 96 hai. For inoculated plants, the concentrations of chlorophyll a and chlorophyll b were significantly higher for the +Si plants compared with the -Si plants at 72 and 96 hai. The results of this study clearly demonstrated that the supply of Si to the wheat plants was associated with lower blast severity in parallel with improved gas exchange performance, resulting in higher energy for mounting successful defense strategies against P. oryzae infection.
This study aimed to analyze the antioxidant system responses and photosynthetic performance of maize cultivars (ECVSCS155 and HIB 32R48H) infected by Stenocarpella macrospora. The activities of some antioxidant enzymes and metabolites and the concentration of reactive oxygen species in maize leaves as well as chlorophyll a fluorescence imaging parameters were assessed. For both cultivars, the enzymatic and non-enzymatic components of the antioxidant system were dramatically altered in the infected leaves. As the disease symptoms became more noticeable, enzyme activities (e.g., peroxidases and catalases) and the concentration of ascorbate and glutathione decreased accordingly. The concentrations of hydrogen peroxide and malondialdehyde equivalents increased, thereby contributing to the intensification of lipid peroxidation upon damage to cell membranes caused by fungal infection. Decreases in maximum fluorescence, maximum PSII quantum efficiency, effective PSII quantum yield and quantum yield of regulated energy dissipation coupled with increases in initial fluorescence and quantum yield of non-regulated energy dissipation were directly related to the progressive loss of photosynthetic activity coupled with the development of oxidative stress during the S. macrospora infection process.
White mold, caused by Sclerotinia sclerotiorum, is one of the most important diseases affecting soybean and its control has been difficult to achieve. This study aimed to investigate the potential of manganese (Mn) phosphite and fluazinam in protecting soybean plants against S. sclerotiorum infection by examining the photosynthetic performance (leaf gas exchange and chlorophyll (Chl) a fluorescence parameters), activities of defense enzymes [chitinase (CHI), β-1,3-glucanase (GLU), phenylalanine ammonia-lyase (PAL), and polyphenol oxidase (PPO)] as well as those related to the antioxidant metabolism (superoxide dismutase (SOD), catalase (CAT), peroxidase (POX), and ascorbate peroxidase (APX)) and the concentrations of hydrogen peroxide (H₂O₂), superoxide (O₂⁻), and malondialdehyde (MDA). White mold development was completely inhibited by fluazinam. Soybean metabolism was not changed by fluazinam. White mold severity was significantly reduced on plants sprayed with Mn phosphite, which showed a better photosynthetic performance than the non-sprayed plants. Mycelial growth of S. sclerotiorum was inhibited by Mn phosphite. Activities of CAT, POX, and SOD decreased while CHI, GLU, and PAL activities increased at 96 hai for Mn phosphite-sprayed plants compared to non-sprayed plants. In conclusion, Mn phosphite affected white mold development and pathogen-induced physiological impairments in soybean leaflets due to its dual mode of action.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.