Helianthus tuberosus(Jerusalem artichoke) tubers improve glucose tolerance and hepatic lipid profile in rats fed a high-fat diet

Objective:To analyze the effects of feeding Helianthus tuberosus(HT) tubers on glucose tolerance and lipid profile in rats fed a high-fat diet(HFD). Methods:A normal HFD or HFD including 10 w/w% HT tubers(HFD + HT) was fed to F334/Jcl rats. After 10 weeks,organ weights,glucose tolerance,and lipid profile were analyzed. Results:The body weight,liver weight,and epidermal fat content in the HFD group were higher than those of the normal group,and similar to those of the HFD + HT group. The oral glucose tolerance test at 10 weeks revealed that the blood glucose level 30 minutes after beginning the test in the HFD + HT group was significantly lower than that in the HFD group. Liver triglyceride and total cholesterol levels in the HFD + HT group were significantly lower than those in the HFD group. Fecal triglyceride and total cholesterol levels in the HFD + HT group were higher than those in the HFD group. Histological analyses revealed that fat and glycogen accumulation increased in the HFD group,but decreased in the HFD + HT group. Conclusions:These results indicate that HT tubers have anti-fatty liver effects based on improvements in glucose tolerance and the hepatic lipid profile.

Accumulation and Distribution Dynamics of Soluble Carbohydrate in Helianthus tuberosus under Drought Stress

With Qingyu 1 and Qingyu 2 as test materials, variation of soluble carbohydrate content in different parts were studied under two types of artificially simulated drought stress （polyethylene glycd PEG-6000 stress and water-controlling stress）. The results showed that under the stress of PEG, soluble carbohydrate content in leaves of Qingyu 1 and Qingyu 2 increased with the prolonging time of stress; soluble carbohydrate content in stems of Qingyu 1 did not show regular changes with the prolonging time of stress, while 30% PEG stress received the best effect on Qingyu 2 after 24 h; soluble carbohydrate content in roots of Qingyu 1 and Qingyu 2 increased with the prolonging time of stress. Under different intensities of water-controUing stress, soluble carbohydrate content in leaves of Qingyu 1 first increased then decreased, while that in leaves of Qingyu 2 increased; soluble carbohydrate content in stems of Qingyu 1 and Qingyu 2 increased with the pro- longing time of water-controlling stress; soluble carbohydrate content in roots of Qingyu 1 decreased with the prolonging time of water-contmlling stress, while that in roots of Qingyu 2 differed slightly.

Inhibitory Effect of Extracts from Helianthus tuberosus Leaves against Phytophthora capsici and Pot Verification Test

By growth rate method, the inhibitory effects of five solvent extracts from Helianthus tuberosus leaves against Phytophthora capsici were studied in the test. The results showed that different solvent extracts all had inhibitory effect against P. capsici, while 12.5 mg/mL of extracts from H. tuberosus leaves with petroleum ether and ethyl acetate as solvents had the highest inhibitory effect against P. capsici, reaching 100%. In case of various solvent extracts with different concentration gradients, ethyl acetate extract had the most significant inhibitory effect; when the concentration was 5 mg/mL, the inhibitory effect of ethyl acetate extract had reached 100% ; when the concentration reduced to 2.5 mg/mL, the inhibitory effect was still （27.91 ±2. 076） %, significantly higher than that of other solvent extracts at the same concentration. The 50 times dilution of ethyl acetate extract from H. tuberosus leaves was selected for pot test against pepper blight. , and the results showed that its control effect against pepper blight reached 100.00%, superior than that of chemical agent 25% metalaxyl WP 400 times dilution.

Research on Adsorption Characteristics of the Helianthus tuberosus Stem s to M ethylene Blue in Water

[Objective] The research aimed to study the adsorption characteristics of the Helianthus tuberosus stems to methylene blue in water. [Method] The optimum condition, adsorption thermodynamic and kinetic characteristics were studied on the methylene blue adsorbed by Helianthus tuberosus stems. [ Result] The equilibrium process was described well by the Langmuir isotherm model. The thermodynamics parameters were enthalpy changes （△H） of -12.147 kJ/mol, Gibb＇S free energy changes （△G） of -25.75 k J/reel, and entropy changes （△S） of 47.21 J/（mol · K）, respectively, at 288 K, indicating that the adsorption thermodynamic of methylene blue adsorbed by helianthus tuberoses stems was a spontaneous and exothermic process. The kinetics of the interactions showed better agreement with the Lagergren second order kinetics. The apparent activation energy （Ea） of adsorption process was 271.7 kJ/mol. [ Conclusion] This study provided the theoretical basis for the development and utilization of low-cost agricultural wastes to remove the hazardous substances in industrial wastewater.

An Analysis on Leaf Traits of 22 Helianthus tuberosus Germplasm Resources Introduced from Abroad

Atomic absorption spectrophotometry,sulfuric acid and potassium dichromate oxidation method and ultraviolet spectrophotometry,were used to determine mineral elements,fiber,the content of chlorogenic acid and flavones in leaves of 24 Helianthus tuberosus Linn.resources,and the characteristics of the leaf introduced from abroad were evaluated.The results showed that the highest water content of 22 species was F12(27.58%),and the lowest was F16(19.02%).The difference in mean water content between the species from Denmark and France was small,but it was lower than that of Qingyu 3 and Qingyu 4.There were 3 orbicular leaves,1 long oval-shaped leaf and 18 oval leaves.The highest K content in the leaves was F19(30.62 mg/g),which was 2.5 times than Qingyu 3.The highest Mg content was D8(14.17 mg/g).The Fe content hadlittledifference,ranging from 0.09 mg/g to 0.19 mg/g.The highest Ca content was D8(26.87 mg/g).The highest level of chlorogenic acid and flavones was F7,2.55%and 1.24 g/100 g respectively.The highest fiber content was F9(16.7%),and the lowest was F19(7.36%).Through the analysis of the main component and the clustering analysis,when the genetic distance was 0.65,the 24 resources can be divided into three major categories.The first category of leaves were mainly oval and orbicular;the second category of leaves were long oval-shaped;the third category of leaves were oval.There was a difference between the various indexes in the leaf of different kinds of H.tuberosus Linn.resources.Finally,F19,D8,F9,F7,D14 and D11,6 specific species(F19,D8,F9,F7,D14 and D11)were screened out for further studies in the future.

Cloning and Expression Pattern of a Gene Encoding a Putative Plastidic ATP/ADP Transporter from Helianthus tuberosus L.

Herein, we report the cloning and molecular characterization of a full cDNA encoding a putative plastidic ATP/ADP transporter, designated HtAATP, for Helianthus tuberosus L. The ATP/ADP translocator protein was isolated from the tuber-cDNA library of H. tuberosus for the first time. The predicted HtAATP protein was judged as a plastidic ATP/ADP translocator protein from its high homology at the amino acid sequence level to the two Arabidopsis thaliana plastidic ATP/ADP translocator proteins AATP1 and AATP2 （84.8% and 79.9% identity, respectively）. Amino acid sequence analysis of the primary structure of HtAATP revealed that it belonged to the plastidic ATP/ADP transporter family. Hydropathy prediction indicated that HtAATP gene product is a highly hydrophobic membrane protein that contains 10 transmembrane domains to form a spanning topology. Southern blotting analysis showed that the HtAATP gene is a single-copy gene in the H. tuberosus genome. Tissue distribution analysis showed that the HtAATP gene is prominently expressed in sink tissues. A stable expression pattern in tubers at different developmental stages implies an active involvement of HtAATP during carbohydrate formation.

Cloning and Functional Analysis of the Bifunctional Agglutinin/Trypsin Inhibitor from Helianthus tuberosus L.

In order to find new insect resistance genes, four homologous cDNAs, hta-a, hta-b, hta-c and hta-d with lengths of 775, 718, 784 and 752 bp, respectively （GenBank accession numbers AF477031-AF477034）, were isolated from a tuber cDNA expression library of Helianthus tuberosus L. Sequence analysis revealed that all four cDNAs contain an open reading frame of 444 bp, coding a polypeptide of 147 amino acid residues, and that the sequences of the cDNAs are very similar to those of the mannose-binding agglutinin genes of the jacalin-related family. In hemagglutination reactions and hapten inhibition assays, affinity-purified HTA （Helianthus tuberosus agglutinin） from induced Escherichia coli BL21（DE3） expressing GST-HTA shows hemagglutination ability and a higher carbohydrate-binding ability for mannose than other tested sugars. Trypsin inhibitory activity was detected in the crude extracts of induced E. coli BL21（DE3） expressing HTA, and was further verified by trypsin inhibitory activity staining on native polyacrylamide gel. The mechanism of interaction between HTA and trypsin was studied by molecular modeling. We found that plenty of hydrogen bonds and electrostatic interactions can be formed between the supposed binding sites of HTA-b and the active site of trypsin, and that a stable HTA/trypsin complex can be formed. The results above imply that HTA might be a bifunctional protein with carbohydrate-binding activity and trypsin inhibitory activity. Moreover, Northern blotting analysis demonstrated that hta is predominantly expressed in tubers of H. tuberosus, very weakly expressed in stems, but not expressed at all in other tissues. Southern blotting analysis indicated that hta is encoded by a multi-gene family. The insect resistance traits have been described in another paper.

Nanoparticles induce the biosynthesis and activity of the new possible therapeutic proteinase source,Talaromyces purpureogenus KJ584844

The need for the bacterial proteinase is rapidly growing,urging to catch a lowcost medium for the microbial fermentation,nanoparticles can play a vital role in this respect.The proteinase of Talaromyces purpureogenus was produced on the tubers of Helianthus tuberosus that also operated as solid support for the fermentation process.The interface amongst nitrogen sources(NH_(4)Cl and yeast extract)was investigated,applying the statistical modeling of central composite design under solid-state fermentation.The optimum medium for proteinase secretion was stimulated by 979.82 mg NH_(4)Cl and 437.68 mg yeast extract per 100 g substrate,yielding 108.15 U/g tubers.Using Plackett-Burman experimental design,the nanoparticles Co,Ni and Fe were assessed as inducers for proteinase stimulants.Co nanoparticles(5 ppm)were the greatest in both proteinase production by the fungus as well as an inducer of the proteolysis process by the enzyme when using faba bean straw as a proteinaceous substrate in the reaction mixture,liberating the extreme quantity of amino acids,compared with the lack of the nanoparticles.The findings suggest the incorporation of Co nanoparticles in both the proteinase fabrication process and during the degradation of proteinaceous materials induce proteinase catalyst.This approach could be extended to modulate the productivity and activity of similar biomolecules.

基于表型数据的菊芋核心种质初步构建

为更好地保存、研究和利用现有菊芋种质资源,本研究以250份种质材料的19个表型性状数据为基础,采用逐步系统聚类并优化聚类和取样方法,初步构建遗传冗余少、代表性强的菊芋核心种质。结果表明,在25%取样比例下多种系统聚类方法抽取的核心种质中,以最短距离法(C4)和优先取样法(S3)组合的C4S3方法所抽取的核心种质评价参数优于其他方法,对原种质的代表性最强。在C4S3法下优化取样比例,结果显示最合适的取样比例为20%,所抽取的核心种质C4S3-20用较少的材料获得了较高的遗传代表性。在C4S3-20方法下继续进行分组取样,评价参数表明分组取样效果不如整体取样,因而不予采纳。主成分分析显示C4S3-20保留了原种质的主成分,去掉了原种质的遗传冗余。最终获得了菊芋核心种质C4S3-20,包括50份材料,其与原种质的性状均值差异百分率为0%,方差差异百分率63.63%,极差符合率为100%,变异系数变化率为131.38%,表型保留比例为96.15%;Shannon多样性指数为1.595。本研究发现该核心种质很好地代表了原种质的遗传多样性,在一定程度上为菊芋资源的有效利用奠定了基础。

菊芋果聚糖合成关键基因1-SST克隆及序列分析

果聚糖是菊芋的主要贮藏物质,其代谢与产量形成和逆境适应性密切相关。为了解菊芋果聚糖合成代谢的机制,本研究以‘青芋1号’为研究对象,利用同源克隆方法,对果聚糖合成关键基因1-SST克隆及序列分析。结果表明,1-SST基因全长为3 925 bp,CDS大小为1 890 bp,由5个内含子和6个外显子组成。经生物信息学分析,预测1-SST蛋白分子量70 934.40 Da,等电点5.10,有两个属于糖基水解酶32家族的保守区,属于亲水性蛋白,以延伸结构(24.48%)和无规则卷曲(56.76%)为主要二级结构,在质膜外行使功能。系统进化分析表明,菊芋1-SST基因与向日葵遗传距离最近,与龙舌兰等不同科不同属的植物进化距离较远。本研究基于对菊芋中调控果聚糖合成代谢1-SST基因的克隆与生物信息学分析,为高等植物果聚糖代谢途径研究奠定一定的理论基础。

干旱胁迫下菊芋果聚糖代谢生理响应特征

菊芋(Helianthus tuberosus L.)以果聚糖作为主要储藏物质,果聚糖有可能在适应干旱胁迫的生理调控中起着重要作用,其干旱条件下响应机制有待进一步研究。本实验以敏感型‘青芋1号’和抗旱型‘青芋3号’为材料,采用人工控水的方法进行干旱胁迫,控水后于不同时期取样并测定植株果聚糖含量及聚合度、果聚糖代谢相关酶活性等生理指标。结果显示:菊芋幼苗在干旱胁迫后,敏感型品种游离糖含量变化明显且处理组果聚糖含量低于对照组,而抗旱型品种的对照组和处理组的果聚糖含量在胁迫前期表现相反,后期同步升高。2个品种菊芋叶片的果聚糖合成酶活性均表现为处理组高于对照组,且抗旱型‘青芋3号’更高,胁迫前期2 d时SST活性达2801.18 kat,后期10 d时IVN、FEH活性分别达到7540.34 kat、7332.36 kat,说明菊芋受到胁迫后,叶片中果聚糖合成酶活性迅速提高,以快速积累果聚糖并增加果聚糖的聚合度,同时向贮存器官快速转运,增强植物抗旱能力;随着胁迫程度的加深,植株通过水解作用将贮存的果聚糖解链,释放出游离单糖以提升渗透调节能力。