Siraitia grosvenorii is rich in sugars. However, researches on fruit quality mainly focus on mogrosides over the years,no systematic study about S. grosvenorii fruit carbohydrates and their monomer sugar constituents has been reported so far. In this study, dry fruit was selected as experimental material. PMP-pre column derivatization HPLC-UV detector method and HPLC-refractive index detector method were employed to determine the carbohydrates components and their contents of monomer sugar constituents in dried fruit flesh, and the methodological study was carried out. The results indicated only two kinds of reducing aldoses-glucose and mannose could be detected by PMP-pre column derivatization HPLC-UV detector method, while five kinds of carbohydrate: glucose, fructose, sucrose, raffinose and polysaccharide could be detected simultaneously by HPLC-refractive index detector method. As compared with PMP-pre column derivatization HPLC-UV detector method, HPLC-refractive index detector method was much more suitable for the general analysis of components and contents of carbohydrate in fruits of S. grosvenorii. Sugar components were the same while concentrations of each monomer sugar constituents were significantly different between different S. grosvenorii varieties. On the other hand, drying methods had obvious effects on the total sugars content as well as the relative contents of 5 kinds of sugar components. The relative contents of sucrose and glucose in freeze dried fruit flesh were much higher than those other 3 kinds of sugars. However, high temperature drying treatment resulted in significant decrease in sucrose and glucose concentrations, the relative contents of fructose and polysaccharide became the most.]]> 2015/12/11 0:00:00 1,2, MA Xiao-Jun^2*, MO Chang-Ming³, ZHAO Huan², TU Dong-Ping², BAI Long-Hua³, FENG Shi-Xin³]]> WANG Hai-Ying^1,2, MA Xiao-Jun^2*, MO Chang-Ming³, ZHAO Huan², TU Dong-Ping², BAI Long-Hua³, FENG Shi-Xin³ 8true Siraitia grosvenorii(Luohanguo)fruit. Due to the existence of bitter mogroside, there are numerous bitter fruits(growth arrest)which are discarded on the branches in the late harvest season. The only difference between bitter and sweet mogrosides on the molecular structure is the number of glucose groups. Therefore, it can be achieved the purpose of improving the taste of bitter mogroside by introducing new glucose residues on its chemical structure. In this paper, glycosyltransferase enzyme-catalyzed reaction was applied to extend the sugar chains of bitter mogroside II. The optimum reaction conditions were determined to be more than 50% purity mogroside II, 2 times of starch in weight, 60 U·g^-1 enzyme according to mogroside II in weight, 60-65 ℃ reaction temperature, and 24 hours reaction time. Based on above reation condtions, bitter S. grosvenorii fruits were collected and used to confirm feasibility of this method. The resulted producd was no longer bitter but slightly sweet, By HPLC-MS detection, the components of the final mixture were determined to be saponins containing 3-6 sugars. This method can improve the taste of mogroside II, and it is a potential approach to utilize resources of abandoned mogroside II in industrial production and bitter S. grosvenorii fruit in agriculture.]]> 2015/12/11 0:00:00 1,2, LIU Jin-Lei¹, LU Feng-Lai¹, SONG Yun-Fei², LI Yuan-Yuan², LI Dian-Peng^1*]]> WANG Lei^1,2, LIU Jin-Lei¹, LU Feng-Lai¹, SONG Yun-Fei², LI Yuan-Yuan², LI Dian-Peng^1* 7true Siraitia grosvenorii(Luohanguo)is a herbaceous perennial medicinal and sweetener plant native in Guangxi of China. It has long been used in traditional Chinese medicine as a natural sweetener and also as a folk medicine for the treatment of lung congestion, colds and sore throats. Many cucurbitane-type triterpene glycosides have been isolated and characterized from S. grosvenorii. The active components responsible for the sweetness are the mogrosides, which are members of the family of triterpene glycosides. Mogroside V has an important prospect as natural and low calorie sweetener, which is nearly 425 times sweeter than sucrose. S. grosvenorii currently depends totally on cultivation in China. It's limitedly applied because the narrow distribution, serious continuous cropping obstacle, low content and high extraction costs of mogroside V. In order to reduce blindness research and determine the appropriate sequencing strategy, the genome survey before large-scale genome sequencing is needed. This survey can provide information about the size and complexity of the whole genome of the S. grosvenorii. The next generation sequencing technology which has been emerged as a cost effective approach for high-through-put sequence determination has dramatically improved the efficiency and speed of genes discovery and genome research. Genome sequencing of S. grosvenorii has the vital significance to reveal the molecular mechanism of yield, content, growth, pest and disease resistance, and provides an efficient approach to improve content and reduce cost of mogroside V by molecular breeding. In this study, the genome size of S. grosvenorii was determined by next-generation sequencing technologies(NGS, Illumina Hiseq^TM 2000). The hybridity percentage, repeats, and GC depth were also estimated by bioinformatics analysis. The results were as follows:(1)Two DNA libraries of 170 bp and 500 bp are constructed. After cleaning and quality checks, more than 18.1 Gb high quality data from the genome is generated, which were assembled into 943 296 contigs and 433 325 scaffolds by SOAP denovo software. The contig and scaffold numbers of the length more than 2 kb were 17 855 and 27 993 separately. The longest length of contig and scaffold were 29 kb and 268 kb. The N50 length of contig and scaffold were 484 bp and 2 331 bp. The average genome size and sequencing coverage depth of S. grosvenorii was about 344.95 Mb and 52 times respectively;(2)The genome of S. grosvernrii had obvious hybridity peak by K-mer method, the hybridity percentage as high as 1.5%. The assembly results showed that the length of contig N50 and scaffold N50 are much shorter than expected. High hybridity percentage of the genome leads to apparently unusual phenomenon between average depth and GC content, and had a low depth distribution area. There was a weak repeat peak behind the main peak, which demonstrated that S.grosvenorii has more repetitive sequences;(3)Whole-genome shotgun sequencing(WGS)should not be used to S. grosvenorii genome sequencing separately, and the Fosmid-to-Fosmid or BAC-to-BAC library could be combinational used for better results. This study would not only obtain the basic resources of genome, but also provide a theoretical basis and target genes for S. grosvenorii in transgenic breeding and genetic engineering.]]> 2015/12/11 0:00:00 2,3, MA Xiao-Jun^1*, MO Chang-Ming³, PAN Li-Mei³, WEI Rong-Chang³, ZHAO Huan¹]]> TANG Qi^2,3, MA Xiao-Jun^1*, MO Chang-Ming³, PAN Li-Mei³, WEI Rong-Chang³, ZHAO Huan¹ 6true in vitro metabolism, mogroside V was incubated with artificial gastric juice and human intestinal bacteria, and a liquid chromatography/mass spectrometry method by LCMS/IT-TOF was applied to analyze the products of mogroside V in artificial gastric juice and human intestinal bacteria culture medium. The results indicated that mogroside V was degraded quickly in artificial gastric juice to be secondary glycosides with two glycosyls or one glycosyl and mogrol without glycosyl. And the longer time it was incubated, the more completely it was degraded, its product was mogrol while the incubation time was 4 h. While in culture medium of human intestinal bacteria, mogroside V was transformed to mogroside IV(isomer)mogroside III(isomer), mogroside II(isomer)and mogroside I(isomer)by deglycosylation reaction, as well as to glycoside with six glycosyls,by glucosylation reaction. Therefore, a general knowledge on the degradation of mogroside V was obtained after this experiment, which would shed light on the further exploitation of mogroside V and Siraitia grosvenorii.]]> 2015/12/11 0:00:00 1, HUANG Zhen-Cong², YAN Xiao-Jie¹, CHEN Yue-Yuan¹, XU Feng³, CAI Shao-Qing³, LI Dian-Peng^1*]]> LU Feng-Lai¹, HUANG Zhen-Cong², YAN Xiao-Jie¹, CHEN Yue-Yuan¹, XU Feng³, CAI Shao-Qing³, LI Dian-Peng^1* 5true Siraitia grosvenorii, belonging to Cucurbitaceae, is an herbaceous perennial plant native to South China and north Thailand, and mostly prevalent in Guilin City of Guangxi Zhuang Autonomous Region. The fruits are widely used as Chinese traditional medicine and meanwhile they contain extremely sweet flesh. As the main active component and sweetner ingredient, mogroside V is a kind of cucurbitane type tetracyclic triterpenes which only exists in the ripe fruits of S. grosvenorii. In the proposed mogoroside V biosynthetic pathway, there are two independent pathways for triterpenoid biosynthesis(MVA pathway and MEP pathway). 3-Hydroxy-3-methylglutaryl coenzyme-A reductase(HMGR), the first rate-limiting enzyme in mevalonate(MVA)pathway of terpenes biosynthesis, is the important regulatory site in mogroside V biosynthetic pathway in S. grosvenorii. However, there is little knowledge about function study of key genes involved in this pathway. In order to further understand mogroside V biosynthetic pathway, the full-length of SgHMGR was obtained by RACE-PCR method from 3 d after fertilization(DAF)of S. grosvenorii fruits based on the unigene of HMGR in transcriptome data, and further conducted by bioinformatic analysis. The recombinant prokaryotic vector was constructed using pET-32a and then transformed into Escherichia coli BL21(DE3)for expression. The results showed that a full-length SgHMGR cDNA was cloned with 1 927 bp and it contained 1 749 bp open reading frame(ORF)encoding a protein of 582 amino acids(aa)(GenBank No.HQ128556.1). The theoretical molecular weight(MW)and isoelectric point(PI)of this predicted protein were 62.6 kD and 8.18, respectively. The predicted protein contained the conserved domain of HMGR and proved it to be a member of HMGR family. SgHMGR protein had the high homology with Cucumis sativus and Cucumis melo of Cucurbitaceae plants, which were both 88%. Its subcellular localization was predicted in plasma membrane or endoplasm. By HMGR gene structure prediction analysis, the predicted SgHMGR protein had two transmembrane domains in N-terminal which were located in 50-72 aa and 93-115 aa, respectively. Besides, there were no predicted signal peptides for SgHMGR protein. In order to avoid the influence of transmembrane domains on the heterologous expression, SgHMGR from 116 amino acids with no transmembrane domains was cloned and named as ‘SgHMGR-1' in this study. The MW and PI of SgHMGR-1 were 49.6 kD and 5.95. The recombined vector was transformed into E. coli BL21(DE3)and expressed by IPTG. The prediction indicated that the MW and PI of the recombined protein of SgHMGR-1 and His were 65.8 kD and 5.95. The results of SDS-PAGE and Western blotting demonstrated that the fusion protein could be expressed in both supernatant and pellet after induction by IPTG overnight and it had highest expression in supernatant at 25 °C. This is the first report about cloning of full-length SgHMGR cDNA and its prokaryotic expression, and the recombined prokaryotic expression vector of SgHMGR was constructed successfully and could be expressed in BL21(DE3)of E.coli, which would lay foundation for further understanding of SgHMGR gene function and molecular regulation in mogroside V biosynthesis and provide reference about HMGR gene function study for other non-model plants.]]> 2015/12/11 0:00:00 1, MO Chang-Ming², TANG Qi³, BAI Long-Hua², MA Xiao-Jun^1*]]> ZHAO Huan¹, MO Chang-Ming², TANG Qi³, BAI Long-Hua², MA Xiao-Jun^1* 4true Siraitia grosvenorii by artificial method, and further improve the correctness in parents' selection, in this article the triploid S. grosvenorii of F1 generation was studied and compared with its tetraploid and diploid by Peroxidase Isozyme and Esterase Isozyme analysis. The results showed that there were certain variations in Peroxidase Isozyme and Esterase Isozyme in different ploidy S. grosvenorii. Compared with the diploid, triploid and tetraploid had the more different mobility isozyme band and more active isozyme band in Peroxidase Isozyme and Esterase Isozyme. Tetraploid had more different mobility isozyme bands than triploid in Peroxidase Isozyme, but they had little difference in isozyme band of Esterase Isozyme. The genetic distance of triploid descendant of F1 generation was closer to its female parent and at the same time, the genetic distance of different triploid descendants of F1 generation were closer to each other when their female tetraploid parents were closer as revealed through sample clustering analysis based on euclidean square distance index according to the data of peroxidase isozyme and esterase isozyme,so that the triploid descendant of F1 generation was genetically closer to its tetraploid female parent. Because it had heterosis in the parents of triploid S. grosvenorii and was genetically closer to female parent, based on this genetic law we could propose the following suggestions about the breeding of improved varieties in triploid S. grosvenorii. The suggestion was that we needed to pay more attention on the excellent character performance of tetraploid female parent in the breeding of triploid S. grosvenorii, and selected the genetic distance was more remarkable between the male and female parent based on the genetic background.]]> 2015/12/11 0:00:00 1, YAN Hai-Feng^1,2,3, LI Hong¹, JIANG Shui-Yuan^1*, LI Feng^1,4]]> HUANG Xi-Yang¹, YAN Hai-Feng^1,2,3, LI Hong¹, JIANG Shui-Yuan^1*, LI Feng^1,4 3true Bacillus subtilis on its soil microbial growth and quality, we investigated the soil microbial number, chlorophyll content, incidence of southern blight, production and the change of mogroside V in the fruits after treating in different concertrations of bio-fertilizer of B. subtilis, in six years of continuous cropping fields, With film-mulching and zone-isolation methods, using Siraitia grosvenorii Yongqing-2 varieties as an experimental materials. The results showed that microbial number significantly improved in the soil below 0-20 cm of the surface after applying the bio-fertilizer of Bacillus subtilis. The number of bacteria and actinomycetes significantly increased, while Fungi that caused plant disease significantly reduced to 86.2. Chlorophyll a and chlorophyll b synthesis was promoted and the accumulation of photosynthesis products increased, while the content of chlorophyll c increased improving plant resistance. The ratio of southern blight decreased while fruit production increased by 17.5%. Fruit level increased up to 7.5% improving for better sale. The inherent quality sublimated that main-effect components mogrosides V reached 1.33%. This would provide evidence that Siraitia grosvenorii growing areas can use bio-fertilizer of Bacillus subtilis to increase the yield and quality.]]> 2015/12/11 0:00:00 1, MO Chang-Ming¹, TANG Qi¹, PAN Li-Mei¹, BAI Long-Hua¹, MA Xiao-Jun^2*]]> FENG Shi-Xin¹, MO Chang-Ming¹, TANG Qi¹, PAN Li-Mei¹, BAI Long-Hua¹, MA Xiao-Jun^2* 2true Siraitia grosvenorii, is a kind of traditional Chinese medicine and used for the treatment of dry cough, sore throat, and constipation etc. Previous chemical investigations revealed that the major valid compounds of S. grosvenorii were mogrosides, belonging to cucurbitane-type triterpenes. Due to the fact that some mogrosides are low content in S. grosvenorii,it is hard to achieve enough amount of these compounds to further study their metabolism and pharmacology etc. So a methodology was established in this paper to obtain enough mogrosides of low content(such as mogroside IIIE, III, IVE, and siamenoside I)by enzymic hydrolysis of 50% mogroside V. The hydrolysis was monitored by RP-HPLC and orthogonal experiments was applied to optimize the reaction conditions. The experiment result indicated the optimal reaction conditions were: in pH 5.6 acetic acid-sodium acetate buffer solution, reaction temperature was 55 ℃, β-dextranase concentration was 400 kU·L^-1, reaction concentration of mogroside V was 0.2 g·L^-1, reaction time was 10 h. It had been verified that the method was repeatable, which could be applied to hydrolyze 50% mogroside V to obtain mogroside IIIE, III, IVE, and siamenoside I. This result also could be a guide for hydrolyzing others secondary-mogrosides.]]> 2015/12/11 0:00:00 1,2, LU Feng-Lai², WANG Lei², CHEN Bing^1,2, XU Feng³, CAI Shao-Qing³, LI Dian-Peng^2*]]> YANG Xue-Rong^1,2, LU Feng-Lai², WANG Lei², CHEN Bing^1,2, XU Feng³, CAI Shao-Qing³, LI Dian-Peng^2* 1true