Phytophthora nicotianae causes substantial economic losses in most countries where tobacco is produced. At present, the control of P. nicotianae mainly depends on chemical methods, with considerable environmental and
health issues. We investigated the effects of ethanol extracts from Scutellaria baicalensis Georgi (SBG) and Magnolia officinalis (MO). On mycelial growth, sporangium formation, and zoospore release of P. nicotianae. Both
extracts inhibited the growth of P. nicotianae, with mycelial growth inhibition rates of 88.92% and 93.92%, respectively, at 40 mg/mL, and EC50 values of 5.39 and 5.74 mg/mL, respectively. The underlying mechanisms were the
inhibition of sporangium formation, the reduction of zoospore number, and the destruction of the mycelium
structure. At an SBG extract concentration of 16.17 mg/mL, the inhibition rates for sporangia and zoospores were
98.66% and 99.39%, respectively. At an MO extract concentration of 2.87 mg/mL, the production of sporangia
and zoospores was completely inhibited. The hyphae treated with the two plant extracts showed different degrees
of deformation and damage. Hyphae treated with SBG extract showed adhesion and local swelling, whereas treatment with MO extract resulted in broken hyphae. Mixture of the extracts resulted in a good synergistic effect. 相似文献
It is critical for spring wheat (Triticum aestivum L.) production in the semi-arid Loess Plateau to understand the impact of nitrogen (N) fertilizer on changes in N metabolism, photosynthetic parameters, and their relationship with grain yield and quality. The photosynthetic capacity of flag leaves, dry matter accumulation, and N metabolite enzyme activities from anthesis to maturity were studied on a long-term fertilization trial under different N rates [0 kg ha?1(N1), 52.5 kg ha?1 (N2), 105 kg ha?1 (N3), 157.5 kg ha?1 (N4), and 210 kg ha?1 (N5)]. It was observed that N3 produced optimum total dry matter (5407 kg ha?1), 1000 grain weight (39.7 g), grain yield (2.64 t ha?1), and protein content (13.97%). Our results showed that N fertilization significantly increased photosynthetic parameters and N metabolite enzymes at all growth stages. Nitrogen harvest index, partial productivity factor, agronomic recovery efficiency, and nitrogen agronomic efficiency were decreased with increased N. Higher N rates (N3–N5) maintained higher photosynthetic capacity and dry matter accumulation and lower intercellular CO2 content. The N supply influenced NUE by improving photosynthetic properties. The N3 produced highest chlorophyll content, photosynthetic rate, stomatal conductance and transpiration rate, grain yield, grain protein, dry matter, grains weight, and N metabolite enzyme activities compared to the other rates (N1, N2, N4, and N5). Therefore, increasing N rates beyond the optimum quantity only promotes vegetative development and results in lower yields.
The vacuoles of the yeast Saccharomyces cerevisiae are closely related to mammalian lysosomes and play a role in macromolecular degradation due to the hydrolytic enzymes present inside. The vacuoles also regulate osmotic pressure and control cellular homeostasis. In previous results, vacuoles were shown to activate the immune response of macrophages by promoting the production of immune-mediated transporters nitric oxide (NO), reactive oxygen species (ROS), and pro-inflammatory cytokines. In this study, the effects of vacuoles on the phagocytosis activity of RAW264.7 cells and their potential as immune enhancers were evaluated, and receptors capable of recognizing vacuoles were examined. An investigation using the phagocytes assay showed that phagocytosis activity increased by the vacuole. Besides, after treatment with TLR2/4 inhibitor, the expression of pro-inflammatory cytokines by vacuoles was significantly reduced and the inducible nitric oxide synthase (iNOS) protein was also significantly reduced. However, treatment with a TLR2 inhibitor did not reduce the production of interleukin-6 (IL)-6, a pro-inflammatory cytokine. As a result of confirming the activation of TLR2/4 using Western blot and immunofluorescence (IF), the TLR2/4 protein expression and fluorescence intensity increased depending on the concentration of vacuoles. Yeast vacuoles significantly upregulate protein expression of p-p65/p-p38 MAPKs. In summary, the vacuoles isolated from S. cerevisiae in macrophages have increased phagocytic ability at a concentration of 20 (µg/ml) and can function as immune-enhancing agent suggesting that TLR2/4 mediated the p38 MAPK/nuclear factor kappa B signaling pathway. 相似文献
