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排序方式: 共有369条查询结果,搜索用时 218 毫秒
11.
Lesaw Bernard Lahuta Joanna Szabliska-Piernik Katarzyna Gowacka Karolina Staanowska Viorica Railean-Plugaru Marcin Horbowicz Pawe Pomastowski Bogusaw Buszewski 《Molecules (Basel, Switzerland)》2022,27(7)
Changes in the metabolome of germinating seeds and seedlings caused by metal nanoparticles are poorly understood. In the present study, the effects of bio-synthesized silver nanoparticles ((Bio)Ag NPs) on grains germination, early seedlings development, and metabolic profiles of roots, coleoptile, and endosperm of wheat were analyzed. Grains germinated well in (Bio)Ag NPs suspensions at the concentration in the range 10–40 mg/L. However, the growth of coleoptile was inhibited by 25%, regardless of (Bio)Ag NPs concentration tested, whereas the growth of roots gradually slowed down along with the increasing concentration of (Bio)Ag NPs. The deleterious effect of Ag NPs on roots was manifested by their shortening, thickening, browning of roots tips, epidermal cell death, progression from apical meristem up to root hairs zone, and the inhibition of root hair development. (Bio)Ag NPs stimulated ROS production in roots and affected the metabolic profiles of all tissues. Roots accumulated sucrose, maltose, 1-kestose, phosphoric acid, and some amino acids (i.e., proline, aspartate/asparagine, hydroxyproline, and branched-chain amino acids). In coleoptile and endosperm, contrary to roots, the concentration of most metabolites decreased. Moreover, coleoptile accumulated galactose. Changes in the concentration of polar metabolites in seedlings revealed the affection of primary metabolism, disturbances in the mobilization of storage materials, and a translocation of sugars and amino acids from the endosperm to growing seedlings. 相似文献
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The entire gene of carboxyltransferase(CT) domain of acetyl-CoA carboxylase(ACCase) from Chinese Spring wheat(CSW) plastid was cloned firstly, and the 2.3 kb gene was inserted into PET28a^+ vector and expressed in E. coil in a soluble state. The (His)6 fusion protein was identified by SDS-PAGE and Western blot. The recombinant protein was purified by affinity chromatography, and the calculated molecular mass(Mr) was 88000. The results of the sequence analysis indicate that the cloned gene(GeneBank accession No. EU124675) was a supplement and revision of the reported ACCase CT partial cDNA from Chinese Spring wheat plastid. The recombinant protein will be significant for us to investigate the recognizing mechanism between ACCase and herbicides, and further to screen new herbicides. 相似文献
16.
Rice Bran as an Excellent Sorbent for Heavy Metals from Aqueous Media, 1. Optimization of Conditions
In this two‐part report, the efficiency of rice bran in removal of heavy metals such as cadmium, lead, zinc, nickel, copper and iron(III) from aqueous solution is investigated. The different experimental conditions such as pH, temperature, volume of solution, bran amount, particle size, exchange time, stirring speed, etc. are studied, and the optimum conditions are selected in part 1 of this series of reports. The efficiency of bran in removal of heavy metals is presented with and without treatments. For treatment, heat or acid, alkali and salt solutions were used. The results obtained show that after treating with saturated sodium chloride solution, its efficiency for Ni2+ and Zn2+ improves. At pH 5, all studied cations have recoveries more than 93% (lead and cadmium 100%). The exchange speed is very high and has preference over the classical ion exchangers. 相似文献
17.
应用逐步统计判别模型预报麦蚜复合种群动态 总被引:3,自引:0,他引:3
本文应用逐步统计判别原理 ,对山东省曲阜地区 1982~ 1994年共 13年麦蚜复合种群动态的系统调查资料进行了统计分析 ,建立了 4个统计判别数学模型 :dy1=0 .1 343x1- 0 .1 472x2 ; y2 =0 .740 9x1- 0 .1 1 85x2 ;y3=- 8.391 5x1- 1 .785 6x2 ; y4=2 .32 40x1- 0 .30 82x2运用所建模型 ,对历史资料进行回代验证 ,其平均历史拟合率在 93%以上 ,并以 1 995年作为独立样本进行试报 ,结果与实际一致。 相似文献
18.
近红外漫反射光谱法测定整粒小麦单株蛋白质含量 总被引:18,自引:2,他引:16
应用近红外漫反射光谱技术(波长为1 100~2 498 nm,分辨率为2 nm),以整粒小麦为材料建立适合于小麦单株分析的蛋白质含量分析系统。首先选取籽粒蛋白质含量具有梯度差异的小麦样品,然后对样品扫描得到原始光谱信息,通过散射校正及数学处理来消除原始光谱噪声,最后分别采用多元线性回归、主成分分析法和偏最小二乘法法建立回归方程。结果表明,优化各项参数后,光谱经过标准乘性散射校正和一阶导数处理后,回归分析采用修正的偏最小二乘法(MPLS)得到的定标模型效果最佳。最终得到的预测方程定标相关系数(RSQ)、交叉验证标准误差(SECV)、交叉验证相关系数(1-VR)分别为0.94,0.42,0.87。数学模型经过验证样品集检验,预测相关系数达到0.88。该模型达到了快速、无损分析单株小麦的要求,非常适合于品质育种的早代选择。 相似文献
19.
The catalytic role of various inert solid supports on acceleration of alcohol fermentation by Saccharomyces cerevisiae was investigated. The enhanced rate of alcohol production was dependent on the nature of the support as well as on the amount
used. Among all the tested supports, chitosan flakes showed the maximum yield of alcohol (93% of theoretical yield). This
higher rate of alcohol production was associated with the twofold increase in the activity of alcohol dehydrogenase over control.
Our results suggest that the addition of a small fraction of solids in submerged fermentations to facilitate cell anchorage
for enhanced metabolic activity is easier and more economical compared to cell immobilization processes.
IICT Communication No. 4266. Some of the results in this article are covered under a patent. 相似文献
20.
Nancy M. Edwards Donatella Peressini James E. Dexter Steven J. Mulvaney 《Rheologica Acta》2001,40(2):142-153
Linear viscoelastic properties (LVP) were determined for five durum wheat doughs and five common wheat doughs (representing
four different classes of Canadian common wheat) of different strength using creep testing. A creep time of 10,000 s was sufficient
to reach a state of steady state flow for all of the doughs. Creep compliances were analyzed in terms of a Burgers model.
For the durum doughs, the entire elastic compliance curve was shifted to higher values as the strength of the dough (as measured
by extensigraph) decreased, while the steady state viscosity increased with strength. For common wheat doughs, the elastic
compliance curves were steeper and the steady state viscosities were lower than for durum doughs of comparable extensigraph
strength. The retardation strengths associated with a maximum in the retardation spectra were lower for the stronger durum
doughs than for common wheat doughs of comparable strength. Differences in the LVP between durum and common wheat doughs of
similar extensigraph strength were interpreted in the context of physical gels with crosslinks and entanglements, whose contributions
to material properties are difficult to distinguish in short-time creep or dynamic measurements. The increased extensibility
of common wheat doughs relative to durum doughs of comparable extensigraph strength was attributed to a higher molecular weight
fraction in the polypeptide chains, similar in some respects to end-linked bimodal polymer networks. The idea of considering
these doughs as physical gels was supported by their stress relaxation behavior.
Received: 6 February 2000 Accepted: 22 August 2000 相似文献