State Key Laboratory of Agrobiotechnology

State Key Laboratory of Agrobiotechnology


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Qin X.,State Key Laboratory of Agrobiotechnology | Liu J.H.,State Key Laboratory of Agrobiotechnology | Liu J.H.,China Agricultural University | Zhao W.S.,State Key Laboratory of Agrobiotechnology | And 6 more authors.
Molecular Plant-Microbe Interactions | Year: 2013

Gibberellin (GA) 20-oxidase (GA20ox) catalyses consecutive steps of oxidation in the late part of the GA biosynthetic pathway. A T-DNA insertion mutant (17S-14) in rice, with an elongated phenotype, was isolated. Analysis of the flanking sequences of the T-DNA insertion site revealed that an incomplete T-DNA integration resulted in enhanced constitutively expression of downstream OsGA20ox3 in the mutant. The accumulation of bioactive GA1 and GA4 were increased in the mutant in comparison with the wild-type plant. Transgenic plants overexpressing OsGA20ox3 showed phenotypes similar to those of the 17S-14 mutant, and the RNA interference (RNAi) lines that had decreased OsGA20ox3 expression exhibited a semidwarf phenotype. Expression of OsGA20ox3 was detected in the leaves and roots of young seedlings, immature panicles, anthers, and pollens, based on β-glucuronidase (GUS) activity staining in transgenic plants expressing the OsGA20ox3 promoter fused to the GUS gene. The OsGA20ox3 RNAi lines showed enhanced resistance against rice pathogens Magnaporthe oryzae (causing rice blast) and Xanthomonas oryzae pv. oryzae (causing bacterial blight) and increased expression of defense-related genes. Conversely, OsGA20ox3- overexpressing plants were more susceptible to these pathogens comparing with the wild-type plants. The susceptibility of wild-type plants to X. oryzae pv. oryzae was increased by exogenous application of GA3 and decreased by S-3307 treatment. Together, the results provide direct evidence for a critical role of OsGA20ox3 in regulating not only plant stature but also disease resistance in rice. © 2013 The American Phytopathological Society.


Ji Z.,State Key Laboratory of Agrobiotechnology | Ji Z.,China Agricultural University | Yan H.,State Key Laboratory of Agrobiotechnology | Yan H.,China Agricultural University | And 5 more authors.
Systematic and Applied Microbiology | Year: 2015

Although the biogeography of rhizobia has been investigated extensively, little is known about the adaptive molecular evolution of rhizobia influenced by soil environments and selected by legumes. In this study, microevolution of Mesorhizobium strains nodulating Caragana in a semi-fixing desert belt in northern China was investigated. Five core genes- atpD, glnII, gyrB, recA, and rpoB, six heat-shock factor genes- clpA, clpB, dnaK, dnaJ, grpE, and hlsU, and five nodulation genes- nodA, nodC, nodD, nodG, and nodP, of 72 representative mesorhizobia were studied in order to determine their genetic variations. A total of 21 genospecies were defined based on the average nucleotide identity (ANI) of concatenated core genes using a threshold of 96% similarity, and by the phylogenetic analyses of the core/heat-shock factor genes. Significant genetic divergence was observed among the genospecies in the semi-fixing desert belt (areas A-E) and Yunnan province (area F), which was closely related to the environmental conditions and geographic distance. Gene flow occurred more frequently among the genospecies in areas A-E, and three sites in area B, than between area F and the other five areas. Recombination occurred among strains more frequently for heat-shock factor genes than the other genes. The results conclusively showed that the Caragana-associated mesorhizobia had divergently evolved according to their geographic distribution, and have been selected not only by the environmental conditions but also by the host plants. © 2015 Elsevier GmbH.


He L.,State Key Laboratory of Agrobiotechnology | Zhou X.,State Key Laboratory of Agrobiotechnology | Yin X.,State Key Laboratory of Agrobiotechnology | Tian L.,State Key Laboratory of Agrobiotechnology | And 3 more authors.
DNA and Cell Biology | Year: 2015

Cholesterol is important for the growth and persistence of Mycobacterium tuberculosis in macrophages. The mce4 locus, which is conserved in both M. tuberculosis and Mycobacterium bovis, is thought to be responsible for cholesterol transport into the bacteria. However, the exact roles of specific genes within the sophisticated mce4 system remain poorly understood. In this study, Mce4A and Mce4E of M. bovis, two proteins that are encoded by the mce4 locus, were expressed in Mycobacterium smegmatis. The recombinant strain expressing the Mce4E protein (M. smeg::E) performed better than that expressing the Mce4A protein (M. smeg::A) in a minimal medium with and without glycerol or cholesterol, which may be the reason why M. smeg::E showed better survival in ANA-1 macrophages than did M. smeg::A. Cytokine expression profiles were similar in macrophages infected with either recombinant strain. We also investigated the role of CD36 in recognizing Mce4A and Mce4E proteins. However, CD36 did not appear to be specific for these proteins and showed little impact on the ultimate clearance of the recombinant strains. Reduced interleukin-1β, inducible nitric oxide synthase, and tumor necrosis factor-alpha mRNA expression at 6h postinfection in macrophages infected with M. smeg::E was observed using a CD36-specific monocular antibody to block the receptor, whereas no obvious changes in the expression of these cytokines were observed in cells infected with M. smeg::A with or without exposure to the CD36 antibody. Conclusively, the different performances of the recombinant strains suggest that the Mce4A and Mce4E proteins enhance mycobacterial adaptation to the harsh environment within macrophages after phagocytosis. © 2015, Mary Ann Liebert, Inc.


Wang J.,China Agricultural University | Wang J.,State Key Laboratory of Agrobiotechnology | Zhou X.,China Agricultural University | Zhou X.,State Key Laboratory of Agrobiotechnology | And 9 more authors.
Tuberculosis | Year: 2013

Bovine tuberculosis is a disease in cattle caused by infection with Mycobacterium bovis. The disease has posed significant economic losses and remains a public health hazard worldwide. Interactions between M. bovis and bovine macrophages have been extensively characterized in various studies, while similar analyses in neutrophils, which are one of the other types of white blood cells in mammals, were often overlooked. Neutrophils provide defense against all microbes and can present a diverse collection of antimicrobial molecules, which play an important role in the control of tuberculosis progression. Much of the available data about the involvement of neutrophils in the killing M. bovis is controversial. In this study, we assessed the effect of in vitro infection with M. bovis on some parameters of neutrophils functions including phenotypic changes, apoptosis rate and inflammatory cytokines production. Our results demonstrated that phagocytosis of M. bovis activated and enhanced bovine neutrophils functions as well as initialed their defense mechanism, but failed to eliminate the mycobacteria. Moreover, autophagy might get involved in the defense infection process functioning as a protective mechanism, and inducible-autophagy by lipopolysaccharides stimulation and starvation treatment could efficiently reverse the inability of neutrophils for killing M. bovis, suggesting a potential target for anti-mycobacterial drug-therapy. © 2013 Elsevier Ltd. All rights reserved.


Chen K.,State Key Laboratory of Agrobiotechnology | Chen K.,Key Laboratory of Animal Epidemiology and Zoonosis | Chen K.,China Agricultural University | Luo Z.,State Key Laboratory of Agrobiotechnology | And 5 more authors.
Virology Journal | Year: 2011

Background: Chicken anemia virus (CAV) infection of newly hatched chickens induces generalized lymphoid atrophy and causes immunosuppressive. VP3, also known as Apoptin, is non-structural protein of CAV. Apoptin specifically induces apoptosis in transformed or tumor cells but not in normal cells. In particular, there are no known cellular homologues of Apoptin hindering genetic approaches to elucidate its cellular function. Although a number of Apoptin-interacting molecules have been identified, the molecular mechanism underlying Apoptin's action is still poorly understood. To learn more about the molecular mechanism of Apoptin's action, we searched for Apoptin associated proteins. Results: Using yeast two-hybrid and colony-life filter approaches we got five positive yeast clones. Through sequencing and BLASTed against NCBI, one of the clones was confirmed containing Gallus heat shock cognate protein 70 (Hsc70). Hsc70 gene was clone into pRK5-Flag plasmid, coimmunoprecipitation assay show both exogenous Hsc70 and endogenous Hsc70 can interact with Apoptin. Truncated Apoptin expression plasmids were made and coimmunoprecipitation were performed, the results show the binding domain of Apoptin with Hsc70 is located between amino acids 30-60. Truncated expression plasmids of Hsc70 were also constructed and coimmunoprecipitation were performed, the results show the peptide-binding and variable domains of Hsc70 are responsible for the binding to Apoptin. Confocal assays were performed and results show that under physiological condition Hsc70 is predominantly distributed in cytoplasm, whereas Hsc70 is translocated into the nuclei and colocalized with Apoptin in the presence of Apoptin in DF-1 cell. Functional studies show that Apoptin markedly down-regulate the mRNA level of RelA/p65 in DF-1 cell. To explore the effect of Hsc70 on Apoptin-mediated RelA/p65 gene expression, we have searched two Hsc70 RNAi sequences, and found that all of them dramatically inhibited the expression of endogenous Hsc70, with the #2 Hsc70 RNAi sequence being the most effective. Knockdown of Hsc70 show Apoptin-inhibited RelA/p65 expression was abolished. Our data demonstrate that Hsc70 is responsible for the down-regulation of Apoptin induced RelA/p65 gene expression. Conclusion: We identified Gallus Hsc70 as an Apoptin binding protein and showed the translocation of Hsc70 into the nuclei of DF-1 cells treated with Apoptin. Hsc70 regulates RelA/p65 gene expression induced by Apoptin. © 2011 Chen et al; licensee BioMed Central Ltd.


Jiao Y.,State Key Laboratory of Agrobiotechnology | Song W.,State Key Laboratory of Agrobiotechnology | Zhang M.,State Key Laboratory of Agrobiotechnology | Lai J.,State Key Laboratory of Agrobiotechnology
BMC Plant Biology | Year: 2011

Background: miRNAs are known to play important regulatory roles throughout plant development. Until recently, nearly all the miRNAs in maize were identified by comparative analysis to miRNAs sequences of other plant species, such as rice and Arabidopsis.Results: To find new miRNA in this important crop, small RNAs from mixed tissues were sequenced, resulting in over 15 million unique sequences. Our sequencing effort validated 23 of the 28 known maize miRNA families, including 49 unique miRNAs. Using a newly established criterion, based on the precision of miRNA processing from precursors, we identified 66 novel miRNAs in maize. These miRNAs can be grouped into 58 families, 54 of which have not been identified in any other species. Five new miRNAs were validated by northern blot. Moreover, we found targets for 23 of the 66 new miRNAs. The targets of two of these newly identified miRNAs were confirmed by 5'RACE.Conclusion: We have implemented a novel method of identifying miRNA by measuring the precision of miRNA processing from precursors. Using this method, 66 novel miRNAs and 50 potential miRNAs have been identified in maize. © 2011 Jiao et al; licensee BioMed Central Ltd.


Wang Y.,State Key Laboratory of Agrobiotechnology | Zhou X.,State Key Laboratory of Agrobiotechnology | Lin J.,State Key Laboratory of Agrobiotechnology | Yin F.,State Key Laboratory of Agrobiotechnology | And 4 more authors.
FEMS Microbiology Letters | Year: 2011

Bovine tuberculosis (BTB) is a chronic infectious disease caused by the pathogen Mycobacterium bovis and poses a long-standing threat to livestock worldwide. To further elucidate the poorly defined BTB immune response in cattle, we utilized monocyte-derived macrophages (MDMs) to assess the gene expression related to M. bovis Beijing strain stimulation. Here, we demonstrate the existence of distinctive gene expression patterns between macrophages of healthy cattle and those exposed to BTB. In comparing MDMs cells from healthy cattle (n=5) and cattle with tuberculosis (n=5) 3h after M. bovis stimulation, the differential expressions of seven genes (IL1β, IL1R1, IL1A, TNF-α, IL10, TLR2 and TLR4) implicated in M. bovis response were examined. The expressions of these seven genes were increased in both the tuberculosis-infected and the healthy cattle to M. bovis stimulation, and two of them (TLR2 and IL10) were significantly different in the tuberculosis and the healthy control groups (P≤0.05). The increase in the expression of the TLR2 gene is more significant in healthy cattle response to stimulation, and the change of IL10 gene expression is more significant in tuberculosis cattle. Additionally, we investigated the cytopathic effect caused by M. bovis stimulation and the relationship between M. bovis and MDMs cells to obtain a general profile of pathogen-host interaction. © 2011 Federation of European Microbiological Societies.


PubMed | Kansas State University and State Key Laboratory of Agrobiotechnology
Type: | Journal: Scientific reports | Year: 2016

Porcine reproductive and respiratory syndrome virus (PRRSV) is one of the most significant etiological agents in the swine industry worldwide. It has been reported that PRRSV infection can modulate host immune responses, and innate immune evasion is thought to play a vital role in PRRSV pathogenesis. In this study, we demonstrated that highly pathogenic PRRSV (HP-PRRSV) infection specifically down-regulated virus-induced signaling adaptor (VISA), a unique adaptor molecule that is essential for retinoic acid induced gene-I (RIG-I) and melanoma differentiation associated gene 5 (MDA5) signal transduction. Moreover, we verified that nsp4 inhibited IRF3 activation induced by signaling molecules, including RIG-I, MDA5, VISA, and TBK1, but not IRF3. Subsequently, we demonstrated that HP-PRRSV nsp4 down-regulated VISA and suppressed type I IFN induction. Importantly, VISA was cleaved by nsp4 and released from mitochondrial membrane, which interrupted the downstream signaling of VISA. However, catalytically inactive mutant of nsp4 abolished its ability to cleave VISA. Interestingly, nsp4 of typical PRRSV strain CH-1a had no effect on VISA. Taken together, these findings reveal a strategy evolved by HP-PRRSV to counteract anti-viral innate immune signaling, which complements the known PRRSV-mediated immune-evasion mechanisms.


PubMed | State Key Laboratory of Agrobiotechnology
Type: Review | Journal: International journal of molecular sciences | Year: 2017

Infectious bursal disease (IBD) is an acute, highly contagious and immunosuppressive poultry disease caused by IBD virus (IBDV). The consequent immunosuppression increases susceptibility to other infectious diseases and the risk of subsequent vaccination failure as well. Since the genome of IBDV is relatively small, it has a limited number of proteins inhibiting the cellular antiviral responses and acting as destroyers to the host defense system. Thus, these virulence factors must be multifunctional in order to complete the viral replication cycle in a host cell. Insights into the roles of these viral proteins along with their multiple cellular targets in different pathways will give rise to a rational design for safer and effective vaccines. Here we summarize the recent findings that focus on the virus-cell interactions during IBDV infection at the protein level.


PubMed | State Key Laboratory of Agrobiotechnology
Type: | Journal: Virology journal | Year: 2011

Chicken anemia virus (CAV) infection of newly hatched chickens induces generalized lymphoid atrophy and causes immunosuppressive. VP3, also known as Apoptin, is non-structural protein of CAV. Apoptin specifically induces apoptosis in transformed or tumor cells but not in normal cells. In particular, there are no known cellular homologues of Apoptin hindering genetic approaches to elucidate its cellular function. Although a number of Apoptin-interacting molecules have been identified, the molecular mechanism underlying Apoptins action is still poorly understood. To learn more about the molecular mechanism of Apoptins action, we searched for Apoptin associated proteins.Using yeast two-hybrid and colony-life filter approaches we got five positive yeast clones. Through sequencing and BLASTed against NCBI, one of the clones was confirmed containing Gallus heat shock cognate protein 70 (Hsc70). Hsc70 gene was clone into pRK5-Flag plasmid, coimmunoprecipitation assay show both exogenous Hsc70 and endogenous Hsc70 can interact with Apoptin. Truncated Apoptin expression plasmids were made and coimmunoprecipitation were performed, the results show the binding domain of Apoptin with Hsc70 is located between amino acids 30-60. Truncated expression plasmids of Hsc70 were also constructed and coimmunoprecipitation were performed, the results show the peptide-binding and variable domains of Hsc70 are responsible for the binding to Apoptin. Confocal assays were performed and results show that under physiological condition Hsc70 is predominantly distributed in cytoplasm, whereas Hsc70 is translocated into the nuclei and colocalized with Apoptin in the presence of Apoptin in DF-1 cell. Functional studies show that Apoptin markedly down-regulate the mRNA level of RelA/p65 in DF-1 cell. To explore the effect of Hsc70 on Apoptin-mediated RelA/p65 gene expression, we have searched two Hsc70 RNAi sequences, and found that all of them dramatically inhibited the expression of endogenous Hsc70, with the #2 Hsc70 RNAi sequence being the most effective. Knockdown of Hsc70 show Apoptin-inhibited RelA/p65 expression was abolished. Our data demonstrate that Hsc70 is responsible for the down-regulation of Apoptin induced RelA/p65 gene expression.We identified Gallus Hsc70 as an Apoptin binding protein and showed the translocation of Hsc70 into the nuclei of DF-1 cells treated with Apoptin. Hsc70 regulates RelA/p65 gene expression induced by Apoptin.

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