Search

Objective: Response surface methodology was used to optimize the extraction process of steroidal glycosides from Cynanchum auriculatum Royle ex Wight by complex enzymatic method, and its effects on alcohol dehydrogenase activity and human hepatoma cell HepG2 were analyzed. Methods: Four experimental factors; enzymolysis duration, temperature, compound enzyme dose and pH were used as responses to a single-factor experiment of the Response Surface Methodology on the steroidal glycoside yields, using perennial C. auriculatum as the target material. The alcohol-induced hepatocyte damage model of HepG2 was used to investigate the contents of ALT, LDH, and GSH and changes in cell shape. Results: The results show that the optimum extraction conditions of steroidal glycoside enzyme were obtained at an enzymolysis duration of 100 min, a temperature of 46 ℃, enzyme dose of 1.30% and pH of 5.0. Consequently, the actual extraction rate of （2.80±0.04）% was achieved using the optimized process conditions, which was close to the expected value. Compared with the model group, it significantly suppresses the growth of ALT and LDH while increasing the amount of intracellular GSH, and the cell damage was restored. Conclusion: The compound enzyme method can effectively extract the steroidal glycosides of Cynanchum auriculatum Royle ex Wight; steroidal glycosides of C. auriculatum have hepatoprotective effect.

In order to understand pathogenicity of Athelia rolfsii to different peanut varieties, six strains with high, moderate and weak virulence were inoculated on resistant and susceptible varieties in the field, occurrence of disease was investigated every week after inoculation. The results showed that the optimal time for investigation was 14 days after inoculation. There was no significant difference in disease index among cultivars inoculated by highly virulent strains ZY2 and SQ1, and weakly virulent strain GP3-1, respectively, but there was significant difference of those inoculated by moderately virulent strains (HA, H1-3 and BL1-1). The disease indices of varieties by strain GP3-1 was low; and was high by strains ZY2 and SQ1. All tested peanut varieties were susceptible to the highly virulent strains ZY2 and SQl.The disease indices between resistant and susceptible varieties showed significant difference among moderately virulent strains. One peanut variety with broad-spectrum resistance to multiple moderately virulent strains was identified. [ABSTRACT FROM AUTHOR]

Ten peanut lines developed by Oil Crops Research Institute (CAAS, Wuhan, China) were evaluated for resistance and yield loss to peanut stem rot caused by Sclerotium rolfsii under natural disease condition and by artificial inoculation. Results indicated that the wilting rates of these lines ranged from 11.0% to 50.0% under natural disease condition and 7 lines had the wilting rates lower than 30. 0%. Peanut yield and wilting rate were significantly negative correlated (r= -0.73,P < 0.05). The wilting rates of these lines (from 66.1% to 94.0%), at two weeks post inoculation in the artificial inoculation experiment,were lower than those (from 66.1% to 97.4%) before harvest, all these lines were susceptible to infection by S. rolfsii. The peanut yield was negatively related with wilting rate by artificial inoculation with the correlation coefficient of -0.85 (P <0.05). The peanut yield loss was higher than 91.7% for all these lines after artificial inoculation. One tolerant line 16 - A13440 was identified. [ABSTRACT FROM AUTHOR]

Due to the methane-contained air leakage flow existing in a high gassy goaf, an experimental system on coal sample's oxidation in low temperature under the condition of methane-contained airflow was designed. Model experiments simulating spontaneous combustion were carried out according to the gas distributing scheme. The formation of the oxidation products CO was studied. The result shows that the temperature for initial production is suppressed and the amount of products produced decreases with the decrease of oxygen volume fraction or increase of methane volume fraction. When fresh air is used to predict the state of coal spontaneous combustion in high gassy goaf, a delayed prediction is caused. Finally, based on the principle of gas-solid chemical reaction kinetics, the variation of reaction rate was analyzed, and the experimental results were-reasonably explained. [ABSTRACT FROM AUTHOR]

R2 R3-MYB transcription factors are ubiquitous in plants, playing a role in the regulation of plant growth, development, and secondary metabolism. In this paper, the R2 R3-MYB transcription factors were identified by bioinformatics analysis of the genomic data of Erigeron breviscapus, and their gene sequences, structures, physical and chemical properties were analyzed. The functions of R2 R3-MYB transcription factors were predicted by cluster analysis. Meanwhile, the expression patterns of R2 R3-MYB transcription factors in response to hormone treatments were analyzed. A total of 108 R2 R3-MYB transcription factors, named EbMYB1-EbMYB108, were identified from the genome of E. breviscapus. Most of the R2 R3-MYB genes carried 2-4 exons. The phylogenetic tree of MYBs in E. breviscapus and Arabidopsis thaliala was constructed, which classified 234 MYBs into 30 subfamilies. The MYBs in the five MYB subfamilies of A.thaliala were clustered into independent clades, and those in E. breviscapus were clustered into four clades. The transcriptome data showed that MYB genes were differentially expressed in different tissues of E. breviscapus and in response to the treatments with exogenous hormones such as ABA, SA, and GA for different time. The transcription of 13 R2 R3-MYB genes did not change significantly, and the expression patterns of some genes were up-regulated or down-regulated with the extension of hormone treatment time. This study provides a theoretical basis for revealing the mechanisms of R2 R3-MYB transcription factors in regulating the growth and development, stress(hormone) response, and active ingredient accumulation in E. breviscapus.

Objective: To observe the regulatory effects of psoralen, oleanolic acid, and stilbene glucoside, three active components of psoralea fruit, glossy privet fruit and tuber fleeceflower root respectively, on Aβ25-35induced self-renewal and neuron-like differentiation of neural stem cells (NSCs)., Methods: Embryonic NSCs werein vitro isolated and cultured from Kunming mice of 14-day pregnancy, and randomly divided into the control group, the Aβ25-35 group, the Aβ25-35 +psoralen group, the Aβ25-35 +oleanolic acid group, and the Aβ25-35 + stilbene glucoside group. The intervention concentration of Aβ25-35 was 25 µmol/L, and the intervention concentration of three active components of Chinese medicine was 10(-7)mol/L. The effect of three active components of Chinese medicine on the proliferation of NSCs was observed by counting method. The protein expression of Tubulin was observed by Western blot and immunofluorescence. The ratio of Tubulin+/DAPI was caculated. Results Compared with the control group, the sperical morphology of NSCs was destroyed in the Aβ25-35 group, the counting of NSCs, the expression of Tubulin protein, and the ratio of Tubulin /DAPI all decreased (P <0.01, P <0.05). Compared with the Aβ25-35 group, the counting of NSCs, the expression of Tubulin protein, and the ratio of Tubulin + /DAPI all increased in the three Chinese medicine treated groups (P <0. 01, P <0. 05)., Conclusions: 25 µmol/L Aβ25-35 could inhibit self-renewal and neuron-like differentiating of NSCs. But psoralen, oleanolic acid, and stilbene glucoside could promote self-renewal of NSCs and neuron-like differentiation.

Melamine was used in foodstuff and feed industry as a feed additive occasionally. In the present work, melamine geometry structure was optimized by density functional theory (DFT) method. Raman and infrared spectra were calculated based on MP2/6-31G sets and DFT/DGTIVP sets, and then two theoretical Raman spectra were carefully compared with other experimental spectra. Good agreements were obtained between the theoretical and experimental results. Melamine structure parameters were given also in the paper including bond lengths and bond angles. Vibrational modes were assigned to all bands in the 550-4 000 cm(-1) range. This work will benefit the measurement research of the content of melamine in foods.

Soybean (Glycine max L.) yield is harmed seriously by pests. Although more and more QTLs for insect-resistance have been developed, the accuracy and validity of these QTLs are not always effective in different populations, for different traits, or by different method of data analysis. It is very important to obtain the real and effective QTL, which would provide great significance for molecular marker assisted selection. In this paper, the information on 81 QTLs related to insect-resistance was collected. All the insect-resistance QTLs were projected on the public genetic linkage map Soymap2 by BioMercator2.1, and a consensus genetic map from different maps with QTLs, genes and other loci was built. A method of meta-analysis was used to deduce the locations of true QTLs with confidence interval of 95%. Twelve and fourteen true QTLs were acquired separately by two ways of individual and integrated meta-analysis, and 6 QTLs showed consensus. All the QTLs were mapped on 9 linkages groups, which were mainly distributed on E, F, H, and M linkages groups as clusters. The QTL intervals were reduced from 15 cM to 3.67 cM in average. Most QTLs were related to resistance to multiple pests besides a soybean pod borer resistance QTL. The results narrowed down the reported QTLs, which provides the basis for QTL fine mapping and gene cloning.

The research progress in genetic linkage map construction of forest tree species both at home and abroad were reviewed in the paper. Two main problems involved in the field were discussed. One was the limitation of the number of individuals of mapping populations and the other was the random markers mostly employed by the majority of studies. These problems have resulted in crossing combination specificity in the constructed maps and the QTLs located on the basis of the maps. As a result,the QTLs discovered up to now have low credibility and poor practicability in marker-assisted selection. Therefore considering the biological characteristics of forest tree species,the selection of the most suitable genetic markers is crucial to obtain a high quality genetic linkage map, and it is both important and necessary to carry out comparative genetic mapping. Progress in the ongoing expressed sequence tag (EST) sequencing projects were summarized and EST polymorphism (ESTP), the most informative and highly conservative marker with known function,as well as the main ESTP detection techniques were elaborated. It was pointed out that ESTP markers should be integrated into the present studies of genetic linkage map construction, QTL mapping and genome comparative mapping. Finally the future prospects in the fields of genetic linkage map and QTL mapping were discussed. In China, such studies around Populus, especially in the local Populus species should make a breakthrough in the related fields.