Yuxi Duan

Shenyang Agricultural University, Feng-t’ien, Liaoning, China

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Publications (7)7.48 Total impact

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    ABSTRACT: The soybean cyst nematode (SCN; Heterodera glycines) is a major detriment to soybean production. The endophytic bacterium Sinorhizobium fredii strain Sneb183 is known to inhibit the activity of SCN. In the present study, soybean seedlings were inoculated with Sneb183, to study the penetration juveniles, and their development inside the roots. The number of cysts in the soybean roots was also examined. The induced systemic resistance in soybean was also examined through the split-root system. Our results revealed that the number of juveniles and cysts significantly decreased as a result of Sneb183 inoculation. Sneb183 also prolonged the developmental stage of SCN in the root to 30 days as compared to 27 days in the control. Furthermore, the number of nematodes in each stage was lower in the Sneb183 treated plants than control plants. We also used a split-root system to show that the S. fredii strain Sneb183 induced a systemic resistance to SCN infection in soybean. The repression rate of SCN penetration was 38.75%. Our study showed that Sneb183 can be an effective biocontrol agent for managing SCN infestation in soybean.
    Journal of Basic Microbiology 06/2014; · 1.20 Impact Factor
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    ABSTRACT: A gene named GmGPX1 encoding glutathione peroxidase (GPX) was cloned and sequenced from soybean roots infested Heterodera glycines by RT-PCR (Reverse Transcription PCR), which is a crucial enzyme in plant cells regulating reactive oxygen species (ROX). The cDNA length of cloned gene was 693bp, flanked by a 5'-untranslated region of 7bp and a 3'-untranslated region of 185bp, containing six exons and five introns. Genomic DNA fragment was located at Glycine max chromosome 5. The open reading frame of cDNA which encodes a polypeptide of 166 amino acid residues and protein molecular weight was 18375.8Da, theoretical isoelectric point 6.59. The deduced amino acid sequence showed about 99% and 64% homology with G max putative PHGPX (XP_003532707.1) and Arabidopsis thaliana GPX (NP_564813.1), respectively. The expression profile of the GmGPX1 in Xiaoliheidou (G. max) under H. glycines infection, which generates oxidative stress, was analyzed. Real time PCR analysis revealed that the GmGPX1 mRNA levels were increased stabilized from 1.3 to 1.47 times after exposure to H. glycines from 12h to 48h, and reduced to 1.07 times at 72h comparing with non-inoculation control. These results suggest that the GmGPX1 gene is induced by H. glycines at early stage in soybean roots and play an important role in removing oxidative damage.
    Journal of Agricultural Science. 05/2012; 4(7).
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    ABSTRACT: Soybean cyst nematode (SCN), Heterodera glycines, is the most devastating pathogen of soybean worldwide. MicroRNAs (miRNAs) are a class of small, non-coding RNAs that are known to play important role in plant stress response. However, there are few reports profiling the miRNA expression patterns during pathogen stress. We sequenced four small RNA libraries from two soybean cultivar (Hairbin xiaoheidou, SCN race 3 resistant, Liaodou 10, SCN race 3 susceptible) that grown under un-inoculated and SCN-inoculated soil. Small RNAs were mapped to soybean genome sequence, 364 known soybean miRNA genes were identified in total. In addition, 21 potential miRNA candidates were identified. Comparative analysis of miRNA profiling indicated 101 miRNAs belong to 40 families were SCN-responsive. We also found 20 miRNAs with different express pattern even between two cultivars of the same species. These findings suggest that miRNA paly important role in soybean response to SCN and have important implications for further identification of miRNAs under pathogen stress.
    PLoS ONE 01/2012; 7(6):e39650. · 3.53 Impact Factor
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    ABSTRACT: To gain insight into the changes in the transcriptome of soybean roots during soybean cyst nematode (SCN) infection, we conducted genome-wide gene expression profiling using serial analysis of gene expression (SAGE) combined with Solexa sequencing. More than 3 million tags were generated from the SCN-infected and uninfected roots, and 366941 and 314591 clean UniTags were obtained from SCN-infected and uninfected samples, respectively. In the SCN-infected sample, 48249 UniTags represented 18114 reference genes. In the uninfected control, 46290 UniTags represented 19323 reference genes. Comparison of tag frequencies identified 1405 genes that were expressed at greater levels in SCN-infected roots than in uninfected roots, and 1191 genes that were expressed at lower levels. Quantitative real-time PCR analyses confirmed the changes in mRNA levels observed in our sequencing analyses. A comparable number of genes were up- and down-regulated in response to nematode infection, indicating that down-regulation of some genes might be essential in the plant response to nematodes. Our SAGE results showed significant changes in expression of many unreported genes involved in nematode infection. Approximately 7% of tags mapped to the antisense strand of genes, indicating widespread antisense transcription. Keywords Glycine max –soybean cyst nematode–gene expression profile–SAGE–Solexa sequencing
    Chinese Science Bulletin 01/2011; 56(18):1904-1911. · 1.37 Impact Factor
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    ABSTRACT: Dynamics of soil nematode communities amended with agrochemicals and bio-control preparations were investigated in a soybean field. The results showed that the frequency of plant non-parasitic nematodes were obviously higher in soil amended with bio-control preparations (Doufeng 1) than with urea and herbicide, however, that of plant parasitic nematodes exhibited an inverse trend.
    Ying yong sheng tai xue bao = The journal of applied ecology / Zhongguo sheng tai xue xue hui, Zhongguo ke xue yuan Shenyang ying yong sheng tai yan jiu suo zhu ban 06/2002; 13(5):638-40.
  • Dandan Liu, Lijie Chen, Yuxi Duan
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    ABSTRACT: Transgenic Bacillus thuringiensis (Bt) rice expressing cry1C gene showed a high level of resistance to leaffolders (Cnaphalocrocis medinalis) and stemborers. Till now, no detection method based on the plasmid molecule as the calibrator has been reported. In this study, one plasmid molecule containing the rice root-specific gene (gos9) endogenous sequence and the cry1C rice 5′ event-specific sequence was developed. Real-time polymerase chain reaction (PCR) method was established using the developed plasmid molecule as the calibrator. Two standard curves for gos9 and the cry1C rice 5′ event-specific sequence showed high PCR efficiency and good linear regression. Limit of quantification of the plasmid molecule in quantitative PCR assays was 40 copies. Biases for 5 and 0.25 % content samples’ quantification were −6.01 and −3.55 % with acceptable standard deviation and repeatability standard deviation, respectively. Comparing with genomic DNA, the plasmid molecule was suitable for cry1C rice quantification as the calibrator. Furthermore, the present study provided a reliable and stable identification and quantification system for monitoring cry1C rice.
    European Food Research and Technology 237(2). · 1.39 Impact Factor