Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 9

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
Apple scar skin viroid (ASSVd) is a serious pathogen of apple fruits that results in severe loss in apple production. Up to nowadays, many ASSVd management options are applied to resist the disease, but the diserable resulits are not achieved. Therefore, this study was conducted in 2010–2012 at experimental field of Penglai City, Shandong Province, China (E 120°57’22’’, N 370°38’33’’) to investigate whether arbuscular mycorrhizal (AM) Glomus versiforme protects Red Fuji apple trees (Malus × domestica Borkh) against apple scar skin viroid. Red Fuji apple trees were inoculated with Glomus versiforme and then potential protection mechanism was explored and compared to noninoculated plants. The results showed that inoculation with Glomus versiforme significantly increased root length colonization rate and clearly decreased the percentage of disease severity of apple scar skin disease. Compared to non-inoculated plants, Glomus versiforme obviously enhanced total nitrogen and phosphorus concentrations in leaves. Root colonization by Glomus versiforme induced an increase in defense-related enzyme activities in fruits, such as the enhanced activities of catalase, ascorbate peroxidase, chitinase and glucanase. Significant differences in acid content of fruit and fruit yield were observed as apple roots were colonized by Glomus versiforme. It is therefore concluded that Glomus versiforme can be regarded as a biocontrol agent to protect apple trees against the infection with ASSVd.
Salt in saline land is regarded as a kind of abiotic stress that limits the productivity of plants and their geographical distribution. To understand the mechanism of how shrub willow clones seedling respond to salt stress at the proteomic level, proteins extracted from seedling leaves of salt sensitive cultivar JW9-6 and salt tolerant cultivar JW2372 were tested under salt stress for the different durations, including 2, 12 and 72 h, using 2-D electrophoresis. Totally, 83 differentially expressed proteins were found using MALDI-TOF/TOF MS. These proteins were divided into 11 classes. The primary findings from this study are: (1) enhanced ROS scavenging capacity leads to increased salt tolerance for the shrub willow that protects redox homeostasis system from being damaged; (2) different measures, e.g., the inhibition of protein synthesis, protein folding and assembly, and enhancing protein proteolysis, were essential for shrub willow seedlings to respond to salt stress; (3) salt stress could affect the pathways of photosynthesis, carbohydrate metabolism, energy supply, and metabolism for amino acid and nitrogen. (4) JW2372 are more salt tolerant than that of cultivar JW9-6 due to overall performance of the above pathways.
Medicago sativa L. cv. Longzhong is a nutritious forage plant in dryland regions of the Loess Plateau with strong drought tolerance and broad adaptability. To understand the adaptation mechanism of alfalfa (M. sativa L. cv. Longzhong) to drought stress, growth, and physiological parameters including levels of chlorophyll content, osmotic adjustment, reactive oxygen species (ROS), and antioxidant enzymes and antioxidants were measured under simulated levels of drought (− 0.40, − 0.80, − 1.20, − 1.60, and − 2.00 MPa). The changes in M. sativa L. cv. Longzhong were compared with those of plants of M. sativa L. cv. Longdong control (Variety I) suited to moderate rainfall areas and M. sativa L. cv. Gannong No. 3 (Variety II) suited to irrigated areas. The results showed that root–shoot ratio, the chlorophyll (a + b) and osmolytes contents, the degree of lipid peroxidation and ROS production, and the levels of antioxidative enzymes and antioxidants increased significantly with increasing drought stress, whereas plant height, aboveground biomass, chlorophyll a/b ratio, leaf water potential (Ψ₁), and relative water content (RWC) decreased in response to drought. The Longzhong variety responded early to beginning drought stress (between 0 and − 0.4 MPa) compared with the controls. Under drought stress (between − 0.4 and − 2.0 MPa), the Longzhong variety had significantly higher belowground biomass, root–shoot ratio, Ψ₁, RWC, catalase (CAT) activity and reduced glutathione content than those of Varieties I and II, but hydrogen peroxide and hydroxyl free radical (OH·) contents were significantly lower. Step regression analysis showed that OH·, CAT, malondialdehyde, superoxide anion-free radical (O₂˙⁻ ), and superoxide dismutase of Longzhong had the most marked response to drought stress. In conclusion, the stronger drought tolerance of the Longzhong variety might be due to its higher water-holding capacity, root–shoot ratio, and ability to coordinate enzymatic and non-enzymatic antioxidant systems, which coordinate the peroxidation and oxidative systems.
Nuclear-encoded chloroplast small heat shock proteins (Cp-sHSPs) play important roles in plant stress tolerance due to their abundance and diversity. Their functions in Primula under heat treatment are poorly characterized. Here, expression analysis showed that the Primula Cp-sHSP gene, PfHSP21.4, was highly induced by heat stress in all vegetative and generative tissues in addition to constitutive expression in certain development stages. PfHSP21.4 was introduced into Arabidopsis, and its function was analysed in transgenic plants. Under heat stress, the PfHSP21.4 transgenic plants showed increased heat tolerance as shown by preservation of hypocotyl elongation, membrane integrity, chlorophyll content and photosystem II activity (Fv/Fm), increased seedling survival and increase in proline content. Alleviation of oxidative damage was associated with increased activity of superoxide dismutase and peroxidase. In addition, the induced expression of HSP101, HSP70, ascorbate peroxidase and Δ1-pyrroline-5-carboxylate synthase under heat stress was more pronounced in transgenic plants than in wild-type plants. These results support the positive role of PfHSP21.4 in response to heat stress in plants.
The application of solid mechanics theory in rock engineering is promoted by the presentation of sheet crack concept and geological model. The special part of rock mass with sheet crack is the problem of structural stability, the failure mechanism of which is different from the structural instability caused by material breakage. First, the rock mass slope with high-steep sheet crack is abstracted into an orthotropic plate to analyze its mechanical forms under different boundary conditions and obtain the non-dimensional buckling critical load of rock mass with sheet crack under different conditions of ratio between thickness and width in the elastic range. Second, the solution toward post-buckling mechanical behaviors of rock mass with sheet crack is processed to obtain the change rules of strength and bearing capacity after buckling, and the analytical solution for post-buckling critical load of rock mass with sheet crack is put forward, providing a new idea for stability analysis of slope and some theoretical reference for similar projects.
Collapse is very common in tunnel construction, which can bring immense casualties and economic losses. The interface of soft and hard rock is the typical location for a tunnel collapse. During Shimenya Tunnel construction, collapse of the section ZK123+370~ZK123+365 of the left tunnel occurred. This paper discusses how distribution of layered rock, attitude of the stratum, hydrogeololgy, and advanced geological prediction can contribute to tunnel collapse. According to collapse mechanisms and in situ collapse conditions, managing and monitoring plans were applied to the tunnel collapse section. To ensure the efficiency and safety of collapse management, convergence displacement and arch crown settlement were measured in the process of tunnel information management. Cause analysis of soft and hard rock tunnel collapse and information management can provide a beneficial reference for avoiding tunnel collapse and developing collapse management programs.
Coal gasification coarse cinder (CGCC) is the main waste in the coal gasification industry, containing low calorific value but high heavy metal residuals. To achieve environmental toxicity stabilization and waste recycling, we developed a manufacturing method of multiple-functional ceramsite from CGCC by pelletizing and sintering. By altering key parameters during the manufacturing process (including CGCC content, sintering temperature, and time), the physical properties and leaching toxicity of ceramsite were evaluated. Sintering temperature was identified with a significantly positive relationship with ceramsite’s compressive strength, whereas CGCC content was negatively correlated with water adsorption. The highest compressive strength (24.00 MPa) and relatively lower water absorption (21.36%) was achieved at 50% CGCC content and 1,150ºC sintering for 30 min. The toxicity tests showed acceptable leaching heavy metals with minimal environmental impact. Considering the energy conservation and the maximal recycling of CGCC, optimal ceramsite manufacturing is suggested as 50% CGCC content and 1,150ºC/10 min sintering temperature/time. Our results indicated that multiple-functional ceramsite manufacturing is a low-cost and environmentally friendly approach for CGCC recycling.
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.