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1.
The jasmonate (JA) and salicylate (SA) signaling pathways in plants provide resistance to herbivorous insects and pathogens. It is known that these pathways interact, sometimes resulting in antagonism between the pathways. We tested how the timing and concentration of elicitation of each pathway influenced the interaction between the jasmonate and salicylate pathways measured in terms of five biochemical responses and biological resistance to caterpillars and bacteria. The salicylate pathway had a stronger effect on the jasmonate pathway than did the reverse. The negative signal interaction was generated by two distinct paths in the plant. A negative interaction in the biochemical expression of the two pathways was most consistent in the simultaneous elicitation experiments compared to when the elicitors were temporally separated by two days. Herbivore bioassays with Spodoptera exigua also consistently reflected an interaction between the two pathways in the simultaneous elicitation experiments. The negative signal interaction reducing biological resistance to the herbivore was also demonstrated in some temporally separated treatment combinations where attenuation of the biochemical response was not evident. Concentration of the elicitors had an effect on the pathway interaction with consistent biochemical and biological antagonism in the high concentration experiments and inconsistent antagonism in the low concentration experiments. The bacterial pathogen, Pseudomonas syringae pv. tomato (Pst), consistently showed reduced lesion development on plants with SA responses activated and, in some experiments, on JA-elicited plants. Resistance to Pst was not reduced or enhanced in dual-elicited plants. Thus, signal interaction is most consistent when elicitors are applied at the same time or when applied at high doses. Signal interaction affected the herbivore S. exigua, but not the pathogen Pst. 相似文献
2.
为减少对电网的污染,在进行光伏并网逆变器设计时,要产生与电网同频、同相的交流电,并使并网逆变器的功率因数接近于1,这就要求滤除电网中的谐波信号.针对数字化并网逆变器,研究基于Matlab仿真软件与数字信号处理器TMS320F2812实现FIR数字滤波器的设计思路,并对仿真结果进行分析,提出了针对电网信号特点的滤波器设计方法,对光伏并网逆变器的设计有一定参考价值. 相似文献
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反应器结构对黄原胶发酵的影响 总被引:7,自引:0,他引:7
本文通过对黄原胶在不同结构的发酵罐上生产结果的研究,分析讨论了发酵罐的搅拌器、罐体高径比、桨叶直径与挡板、加热系统及通气量控制等因素对发酵的影响。认为加大高径比值,增加桨叶层数,减小桨叶直径,消除挡板的剪切影响,增大调温系统的传热面积并降低热源温度,控制合理的通气量等方式都是提高发酵产品产量与质量的有效途径。 相似文献
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ABSTRACT: The present study was conducted to investigate the effects of a low (0.5%) and a high (2.0%) dietary dose of freeze‐dried Chinese cabbage (CC) (Brassica campestris L.) powder in a type‐2 diabetes (T2D) model of rats. Five‐week‐old male Sprague–Dawley rats were fed a high fat (HF)‐containing diet for 2 wk then randomly divided into 4 groups of 8 animals, namely: normal control (NC), diabetic control (DBC), Chinese cabbage low (CCL, 0.5%), and Chinese cabbage high (CCH, 2.0%) groups. Diabetes was induced by an intraperitoneal injection of streptozotocin (STZ; 40 mg/kg body weight) in all groups except the NC group. After 4 wk feeding of experimental diets, although food intake was not different among the DBC, CCL, and CCH groups, body weight gain was significantly (P < 0.05) higher in the CCH group compared to the DBC group. Relatively higher serum insulin concentrations and better glucose tolerance were observed in the CC‐fed groups compared to the DBC group; however, the results were not significantly different. Fasting blood glucose, blood glycated hemoglobin (HbA1c), liver weight, and liver glycogen levels were not influenced by the CC‐containing diets. Additionally, hypertriglyceridemic tendencies were observed in the CC‐fed groups compared to the NC and DBC groups, while difference observed for total‐, HDL‐, and LDL‐cholesterols between the groups were negligible. Results of this study suggest that up to 2% dietary dose of freeze‐dried CC is not significantly effective to reduce diabetes‐related symptoms in an HF diet‐fed STZ‐induced T2D model of rats. 相似文献
7.
In Vitro Determination of the Antifungal Activity of Artemisia campestris Essential Oil from Algeria
Abderrahmane Houicher Hind Hechachna Fatih Özogul 《International Journal of Food Properties》2016,19(8):1749-1756
The chemical composition of the essential oil isolated from the aerial parts of Artemisia campestris from Algeria and its antifungal activity against 10 filamentous fungal strains were investigated. The A. campestris essential oil was obtained in a yield of 0.71% (v/w). The major constituents of the oil were α-pinene (18.65%), β-pinene (16.78%), β-myrcene (17.34%), and germacrene D (10.34%). Our study showed that A. campestris essential oil was a potent antifungal agent against some pathogenic fungal species. Fusarium graminearum was the most sensitive strain to A. campestris essential oil with minimal inhibitory concentration and minimal fungicidal concentration values of 1.25 µL/mL (v/v). The essential oil also exhibited a strong fungicidal activity against the tested fungi, except for Penicillium citrinum, P. viridicatum, and Aspergillus niger (MFC >20 µL/mL). Our findings suggested the application of A. campestris essential oil as a biofungicide in order to reduce the dependence on synthetic fungicides and ensure food safety and quality. 相似文献
8.
目的优化黄原胶的发酵工艺以提高黄原胶的产量及黏度。方法采用摇瓶发酵,改变实验条件,包括培养基中碳源、氮源的种类和浓度,复合氮源的组成及含量,无机盐的组成及含量,柠檬酸和碳酸钙的含量等。通过测定发酵液黏度、粗胶含量来确定较为适合的发酵工艺。结果通过实验得到最佳培养基组成为:蔗糖4%,硫酸铵0.1%,豆饼粉0.3%,柠檬酸0.1%,硫酸镁0.01%,碳酸钙0.02%;培养条件为:500 mL摇瓶发酵装液量100 mL,转速220 r/min,发酵温度28.5℃,培养72h。进行了发酵罐发酵实验,黄原胶的发酵产量可以达到25.02g/L,发酵液的终黏度5847cP。结论通过工艺优化,黄原胶产量及黏度均得到提高。 相似文献
9.
Adamantia Varympopi Anastasia Dimopoulou Dimitris Papafotis Pavlos Avramidis Ioannis Sarris Theodora Karamanidou Alexandra Kaldeli Kerou Afroditi Vlachou Eleftherios Vellis Andreas Giannopoulos Kosmas Haralampidis Ioannis Theologidis Dimitris G. Hatzinikolaou Alexander Tsouknidas Nicholas Skandalis 《International journal of molecular sciences》2022,23(8)
Copper-based bactericides have appeared as a new tool in crop protection and offer an effective solution to combat bacterial resistance. In this work, two copper nanoparticle products that were previously synthesized and evaluated against major bacterial and fungal pathogens were tested on their ability to control the bacterial spot disease of tomato. Growth of Xanthomonas campestris pv. vesicatoria, the causal agent of the disease, was significantly suppressed by both nanoparticles, which had superior function compared to conventional commercial formulations of copper. X-ray fluorescence spectrometry measurements in tomato leaves revealed that bioavailability of copper is superior in the case of nanoparticles compared to conventional formulations and is dependent on synthesis rather than size. This is the first report correlating bioavailability of copper to nanoparticle efficacy. 相似文献
10.
述了塑料材料摩擦、磨损的研究概况,详细阐述了摩擦因数、载荷、温度、速度、润滑、表面粗糙度pv值和热性能等因素对塑料材料摩擦性能的影响,介绍了磨损的衡量标准和测量方法. 相似文献