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Wang X.,Chinese Academy of Agricultural Sciences | Wang X.,Key Laboratory of Biology and Genetic Improvement of Oil Crops | Wang X.,Laboratory of Risk Assessment for Oilseeds Products Wuhan | Li P.,Chinese Academy of Agricultural Sciences | And 3 more authors.
Food Chemistry | Year: 2015

An automated, size-exclusion solid phase extraction (SPE)-UPLC-MS/MS protocol without pre-treatment of samples was developed to screen for four mycotoxins (OTA, ZEN, AFB1, and AFM1) in liquid milk and milk powder. Firstly, a mixed macropore-silica gel cartridge was established as a size-exclusion SPE column. The proposed methodology could be a candidate in green analytical chemistry because it saves on manpower and organic solvent. Permanent post-column infusion of mycotoxin standards was used to quantify matrix effects throughout the chromatographic run. Matrix-matched calibration could effectively compensate for matrix effects, which may be caused by liquid milk or milk powder matrix. Recovery of the four mycotoxins in fortified liquid milk was in the range 89-120% and RSD 2-9%. The LOD for the four mycotoxins in liquid milk and milk powder were 0.05-2 ng L-1 and 0.25-10 ng kg-1, respectively. The LOQ for the four mycotoxins in liquid milk and milk powder were 0.1-5 ng L-1 and 0.5-25 ng kg-1, respectively. © 2014 Elsevier Ltd. All rights reserved.

Zhang Y.,Wuhan University | Shen Y.Y.,Wuhan University | Wu X.M.,Key Laboratory of Biology and Genetic Improvement of Oil Crops | Wang J.B.,Wuhan University
Biologia Plantarum | Year: 2016

Members of the Brassicaceae family disperse their seeds through a mechanism commonly referred to as fruit dehiscence or pod shatter. Pod shatter is influenced by variations in valve margin structure and the molecular control pathways related to valve development. Anatomical patterns of the dehiscence zone from Brassica napus L., Brassica rapa L., Brassica carinata L. and Sinapis alba L., representing fruit types differing in pod shatter resistance, were compared using histological staining. The pod shatter-susceptible plant B. napus showed increased lignin deposition at the vascular bundle of the replum, as well as increased separation of cell layers. In pod shatter-resistant plants S. alba, B. rapa, and B. carinata, we observed two layers of lignified valve margin cells. From these four species, we isolated and identified homologs of SHATTERPROOF (SHP1, SHP2), INDEHISCENT (IND), ALCATRAZ (ALC), FRUITFULL (FUL), AGAMOUS (AG), NAC SECONDARY WALL THICKENING PROMOTING FACTOR1 (NST1), and SEEDSTICK (STK) genes involved in fruit development and pod shatter in Arabidopsis. Transcriptional analysis of these eight genes was performed by RT-qPCR and the results demonstrated that differences in the expression patterns of eight genes may be associated with dehiscence variation within these four species. © 2016 Springer Science+Business Media Dordrecht

Wang Y.,Chinese Academy of Agricultural Sciences | Wang Y.,Key Laboratory of Biology and Genetic Improvement of Oil Crops | Wang Y.,Key Laboratory of Detection for Mycotoxins | Wang Y.,Laboratory of Risk Assessment for Oilseeds Products | And 12 more authors.
Analytical Chemistry | Year: 2013

Anti-idiotypic antibodies recognize the antigenic determinants of an antibody, thus they can be used as surrogate antigens. Single-domain antibodies from camlid heavy-chain antibodies with the benefit features of small size, thermostability, and ease in expression, are leading candidates to produce anti-idiotypic antibodies. In this work, we constructed an antibody phage library from the mRNA of an alpaca immunized with an antiaflatoxin monoclonal antibody (mAb) 1C11. Three anti-idiotypic VHH antibodies were isolated and applied to immunoassay toward aflatoxin as a coating antigen. The best immunoassay developed with one of these VHH antibodies shows an IC50 of 0.16 ng/mL toward aflatoxin B1 and cross-reactivity toward aflatoxin B2, G1, and G2 of 90.4%, 54.4%, and 37.7%, respectively. The VHH-based immunoassay was successfully applied to the analysis of peanuts, corn, and rice, which are the predominant commodities regularly contaminated by aflatoxins. A good correlation (r2 = 0.89) was found between the data obtained from the conventional ELISA and the ELISA based on a VHH coating antigen for the analysis of aflatoxins in peanuts and feedstuff. The use of biotechnology in developing the surrogate, the absence of standard aflatoxin and organic solvents in the synthesis procedures, and the reproducibility of the VHH antibody makes it an ideal strategy for replacing conventional synthesized antigens. © 2013 American Chemical Society.

Wang Y.,Chinese Academy of Agricultural Sciences | Wang Y.,Key Laboratory of Biology and Genetic Improvement of Oil Crops | Wang Y.,Key Laboratory of Detection for Mycotoxins | Wang Y.,Laboratory of Risk Assessment for Oilseeds Products Wuhan | And 9 more authors.
Journal of Agricultural and Food Chemistry | Year: 2013

To search for an alternative to using protein conjugated aflatoxin as a coating antigen in aflatoxin detection by an ELISA method, a random-8-peptide library was constructed and used as a source of peptides that mimic aflatoxins (termed as mimotopes). Five mimotope peptides were obtained by panning-elution from the library and were successfully used in an indirect competitive ELISA for analyzing total aflatoxin concentration. The assay exhibited an IC50 value of 14 μg/kg in samples (with 1 in 7 dilution of sample extract) for aflatoxins. The linear range is 4-24 μg/kg. Further validation indicated relatively good recovery (60-120%) in peanut, rice and corn. Natural contaminated samples (peanut and feedstuff) were analyzed for aflatoxin concentration by both conventional ELISA and phage ELISA. The results showed good correlation. It can be concluded that the mimotope preparation is an effective substitute for the aflatoxin based coating antigen in ELISA and can be used in real sample analysis. © 2013 American Chemical Society.

Tong C.,Key Laboratory of Biology and Genetic Improvement of Oil Crops | Tong C.,Chinese Academy of Agricultural Sciences | Wang X.,Key Laboratory of Biology and Genetic Improvement of Horticultural Crops | Wang X.,Chinese Academy of Agricultural Sciences | And 13 more authors.
BMC Genomics | Year: 2013

Background: The species Brassica rapa (2n=20, AA) is an important vegetable and oilseed crop, and serves as an excellent model for genomic and evolutionary research in Brassica species. With the availability of whole genome sequence of B. rapa, it is essential to further determine the activity of all functional elements of the B. rapa genome and explore the transcriptome on a genome-wide scale. Here, RNA-seq data was employed to provide a genome-wide transcriptional landscape and characterization of the annotated and novel transcripts and alternative splicing events across tissues. Results: RNA-seq reads were generated using the Illumina platform from six different tissues (root, stem, leaf, flower, silique and callus) of the B. rapa accession Chiifu-401-42, the same line used for whole genome sequencing. First, these data detected the widespread transcription of the B. rapa genome, leading to the identification of numerous novel transcripts and definition of 5'/3' UTRs of known genes. Second, 78.8% of the total annotated genes were detected as expressed and 45.8% were constitutively expressed across all tissues. We further defined several groups of genes: housekeeping genes, tissue-specific expressed genes and co-expressed genes across tissues, which will serve as a valuable repository for future crop functional genomics research. Third, alternative splicing (AS) is estimated to occur in more than 29.4% of intron-containing B. rapa genes, and 65% of them were commonly detected in more than two tissues. Interestingly, genes with high rate of AS were over-represented in GO categories relating to transcriptional regulation and signal transduction, suggesting potential importance of AS for playing regulatory role in these genes. Further, we observed that intron retention (IR) is predominant in the AS events and seems to preferentially occurred in genes with short introns. Conclusions: The high-resolution RNA-seq analysis provides a global transcriptional landscape as a complement to the B. rapa genome sequence, which will advance our understanding of the dynamics and complexity of the B. rapa transcriptome. The atlas of gene expression in different tissues will be useful for accelerating research on functional genomics and genome evolution in Brassica species. © 2013 Tong et al.; licensee BioMed Central Ltd.

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