Publications by authors named "Xiao-Feng Dai"

40 Publications

The secretome of Verticillium dahliae in collusion with plant defence responses modulates Verticillium wilt symptoms.

Biol Rev Camb Philos Soc 2022 Apr 27. Epub 2022 Apr 27.

State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.

Verticillium dahliae is a notorious soil-borne pathogen that enters hosts through the roots and proliferates in the plant water-conducting elements to cause Verticillium wilt. Historically, Verticillium wilt symptoms have been explained by vascular occlusion, due to the accumulation of mycelia and plant biomacromolecule aggregation, and also by phytotoxicity caused by pathogen-secreted toxins. Beyond the direct cytotoxicity of some members of the secretome, this review systematically discusses the roles of the V. dahliae secretome in vascular occlusion, including the deposition of polysaccharides as an outcome of plant cell wall destruction, the accumulation of fungal mycelia, and modulation of plant defence responses. By modulating plant defences and hormone levels, the secretome manipulates the vascular environment to induce Verticillium wilt. Thus, the secretome of V. dahliae colludes with plant defence responses to modulate Verticillium wilt symptoms, and thereby bridges the historical concepts of both toxin production by the pathogen and vascular occlusion as the cause of wilting symptoms.
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http://dx.doi.org/10.1111/brv.12863DOI Listing
April 2022

A secreted ribonuclease effector from Verticillium dahliae localizes in the plant nucleus to modulate host immunity.

Mol Plant Pathol 2022 Apr 1. Epub 2022 Apr 1.

The State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China.

The arms race between fungal pathogens and plant hosts involves recognition of fungal effectors to induce host immunity. Although various fungal effectors have been identified, the effector functions of ribonucleases are largely unknown. Herein, we identified a ribonuclease secreted by Verticillium dahliae (VdRTX1) that translocates into the plant nucleus to modulate immunity. The activity of VdRTX1 causes hypersensitive response (HR)-related cell death in Nicotiana benthamiana and cotton. VdRTX1 possesses a signal peptide but is unlikely to be an apoplastic effector because its nuclear localization in the plant is necessary for cell death induction. Knockout of VdRTX1 significantly enhanced V. dahliae virulence on tobacco while V. dahliae employs the known suppressor VdCBM1 to escape the immunity induced by VdRTX1. VdRTX1 homologs are widely distributed in fungi but transient expression of 24 homologs from other fungi did not yield cell death induction, suggesting that this function is specific to the VdRTX1 in V. dahliae. Expression of site-directed mutants of VdRTX1 in N. benthamiana leaves revealed conserved ligand-binding sites that are important for VdRTX1 function in inducing cell death. Thus, VdRTX1 functions as a unique HR-inducing effector in V. dahliae that contributes to the activation of plant immunity.
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http://dx.doi.org/10.1111/mpp.13213DOI Listing
April 2022

Verticillium dahliae CFEM proteins manipulate host immunity and differentially contribute to virulence.

BMC Biol 2022 02 23;20(1):55. Epub 2022 Feb 23.

The State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.

Background: Verticillium dahliae is a fungal pathogen that causes a vascular wilt on many economically important crops. Common fungal extracellular membrane (CFEM) domain proteins including secreted types have been implicated in virulence, but their roles in this pathogen are still unknown.

Results: Nine secreted small cysteine-rich proteins (VdSCPs) with CFEM domains were identified by bioinformatic analyses and their differential suppression of host immune responses were evaluated. Two of these proteins, VdSCP76 and VdSCP77, localized to the plant plasma membrane owing to their signal peptides and mediated broad-spectrum suppression of all immune responses induced by typical effectors. Deletion of either VdSCP76 or VdSCP77 significantly reduced the virulence of V. dahliae on cotton. Furthermore, VdSCP76 and VdSCP77 suppressed host immunity through the potential iron binding site conserved in CFEM family members, characterized by an aspartic acid residue in seven VdSCPs (Asp-type) in contrast with an asparagine residue (Asn-type) in VdSCP76 and VdSCP77. V. dahliae isolates carrying the Asn-type CFEM members were more virulent on cotton than those carrying the Asp-type.

Conclusions: In the iron-insufficient xylem, V. dahliae is likely to employ the Asp-type CFEM members to chelate iron, and Asn-type CFEM members to suppress immunity, for successful colonization and propagation in host plants.
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http://dx.doi.org/10.1186/s12915-022-01254-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8867779PMC
February 2022

Impact of advanced maternal age on maternal and neonatal outcomes in preterm birth.

Ginekol Pol 2022 Jan 24. Epub 2022 Jan 24.

Department of Obstetrics and Gynecology, The First Affiliated Hospital of Fujian Medical University, Fuzhou, China.

Objectives: The aim of this study was to investigate the influence of advanced maternal age on the maternal and neonatal outcomes of preterm pregnancies.

Material And Methods: The characteristics of patients admitted to the Department of Obstetrics and Gynecology, The First Affiliated Hospital of Fujian Medical University between January 2015 and March, 2019 were retrospectively reviewed. The maternal and neonatal outcomes were compared between advanced maternal age group (≥ 35 years) and younger age group (18-34 years). Statistical analysis was performed by applying the SPSS software.

Results: The study population consisted of 986 pregnancies with preterm delivery and 1094 liveborn preterm infants. Multivariate analyses demonstrated that mothers of advanced age were more likely to suffer iatrogenic preterm birth, placenta previa, preeclampsia, gestational diabetes mellitus and postpartum hemorrhage, but less likely to suffer multiple gestation. In terms of neonatal outcomes, advanced maternal age was associated with a decreased rate of low birthweight in an adjusted model without multiple gestation. However, with multiple gestation included in the adjusted model, advanced maternal age was only associated with an increased rate of hyperbilirubinemia.

Conclusions: Advanced maternal age was a risk factor for adverse pregnancy outcomes including iatrogenic preterm birth, placenta previa, preeclampsia, gestational diabetes mellitus, postpartum hemorrhage, and a protective factor for multiple gestation. Regarding neonatal outcomes, advanced maternal age was related to a decreased rate of low birthweight or an increased rate of hyperbilirubinemia depending on the adjustment for multiple gestation.
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http://dx.doi.org/10.5603/GP.a2021.0224DOI Listing
January 2022

Identification of long non-coding RNAs in Verticillium dahliae following inoculation of cotton.

Microbiol Res 2022 Apr 6;257:126962. Epub 2022 Jan 6.

State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China. Electronic address:

Long non-coding RNAs (lncRNAs) play important roles in diverse biological processes. However, these functions have not been assessed in Verticillium dahliae, a soil-borne fungal pathogen that causes devastating wilt diseases in many crops. The discovery and identity of novel lncRNAs and their association with virulence may contribute to an increased understanding of the regulation of virulence in V. dahliae. Here, we identified a total of 352 lncRNAs in V. dahliae. The lncRNAs were transcribed from all V. dahliae chromosomes, typically with shorter open reading frames, lower GC content, and fewer exons than protein-coding genes. In addition, 308 protein-coding genes located within 10 kb upstream and 10 kb downstream of lncRNAs were identified as neighboring genes, and which were considered as potential targets of lncRNA. These neighboring genes encode products involved in development, stress responses, and pathogenicity of V. dahliae, such as transcription factors (TF), kinase, and members of the secretome. Furthermore, 47 lncRNAs were significantly differentially expressed in V. dahliae following inoculation of susceptible cotton (Gossyoiumhisutum) cultivar Junmian No.1, suggesting that lncRNAs may be involved in the regulation of virulence in V. dahliae. Moreover, correlations in expression patterns between lncRNA and their neighboring genes were detected. Expression of lncRNA012077 and its neighboring gene was up-regulated 6 h following inoculation of cotton, while the expression of lncRNA007722 was down-regulated at 6 h but up-regulated at 24 h, in a pattern opposite to that of its neighboring gene. Overexpression of lncRNA012077 in wild-type strain (Vd991) enhanced its virulence on cotton while overexpression of lncRNA009491 reduced virulence. Identification of novel lncRNAs and their association with virulence may provide new targets for disease control.
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http://dx.doi.org/10.1016/j.micres.2022.126962DOI Listing
April 2022

Functional Genomics and Comparative Lineage-Specific Region Analyses Reveal Novel Insights into Race Divergence in Verticillium dahliae.

Microbiol Spectr 2021 12 22;9(3):e0111821. Epub 2021 Dec 22.

State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protectiongrid.460599.7, Chinese Academy of Agricultural Sciences, Beijing, China.

Verticillium dahliae is a widespread soilborne fungus that causes Verticillium wilt on numerous economically important plant species. In tomato, until now, three races have been characterized based on the response of differential cultivars to V. dahliae, but the genetic basis of race divergence in V. dahliae remains undetermined. To investigate the genetic basis of race divergence, we sequenced the genomes of two race 2 strains and four race 3 strains for comparative analyses with two known race 1 genomes. The genetic basis of race divergence was described by the pathogenicity-related genes among the three races, orthologue analyses, and genomic structural variations. Global comparative genomics showed that chromosomal rearrangements are not the only source of race divergence and that race 3 should be split into two genotypes based on orthologue clustering. Lineage-specific regions (LSRs), frequently observed between genomes of the three races, encode several predicted secreted proteins that potentially function as suppressors of immunity triggered by known effectors. These likely contribute to the virulence of the three races. Two genes in particular that can act as markers for race 2 and race 3 ( and , respectively) contribute to virulence on tomato, and the latter acts as an avirulence factor of race 3. We elucidated the genetic basis of race divergence through global comparative genomics and identified secreted proteins in LSRs that could potentially play critical roles in the differential virulence among the races in V. dahliae. Deciphering the gene-for-gene relationships during host-pathogen interactions is the basis of modern plant resistance breeding. In the Verticillium dahliae-tomato pathosystem, two races (races 1 and 2) and their corresponding avirulence () genes have been identified, but strains that lack these two genes exist in nature. In this system, race 3 has been described, but the corresponding gene has not been identified. We -sequenced genomes of six strains and identified secreted proteins within the lineage-specific regions (LSRs) distributed among the genomes of the three races that could potentially function as manipulators of host immunity. One of the LSR genes, , was confirmed as the gene for race 3. The results indicate that differences in transcriptional regulation may contribute to race differentiation. This is the first study to describe these differences and elucidate roles of secreted proteins in LSRs that play roles in race differentiation.
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http://dx.doi.org/10.1128/Spectrum.01118-21DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8694104PMC
December 2021

Transcriptome Analysis of a Cotton Cultivar Provides Insights into the Differentially Expressed Genes Underlying Heightened Resistance to the Devastating Verticillium Wilt.

Cells 2021 10 30;10(11). Epub 2021 Oct 30.

National Cotton Industry Technology System Liaohe Comprehensive Experimental Station, The Cotton Research Center of Liaoning Academy of Agricultural Sciences, Liaoning Provincial Institute of Economic Crops, Liaoyang 111000, China.

Cotton is an important economic crop worldwide. Verticillium wilt (VW) caused by () is a serious disease in cotton, resulting in massive yield losses and decline of fiber quality. Breeding resistant cotton cultivars is an efficient but elaborate method to improve the resistance of cotton against infection. However, the functional mechanism of several excellent VW resistant cotton cultivars is poorly understood at present. In our current study, we carried out RNA-seq to discover the differentially expressed genes (DEGs) in the roots of susceptible cotton cultivar Junmian 1 (J1) and resistant cotton cultivar Liaomian 38 (L38) upon 991 inoculation at two time points compared with the mock inoculated control plants. The potential function of DEGs uniquely expressed in J1 and L38 was also analyzed by GO enrichment and KEGG pathway associations. Most DEGs were assigned to resistance-related functions. In addition, resistance gene analogues (RGAs) were identified and analyzed for their role in the heightened resistance of the L38 cultivar against the devastating 991. In summary, we analyzed the regulatory network of genes in the resistant cotton cultivar L38 during infection, providing a novel and comprehensive insight into VW resistance in cotton.
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http://dx.doi.org/10.3390/cells10112961DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8616101PMC
October 2021

Rhizosphere Microbiomes of Potato Cultivated under Treatment Influence the Quality of Potato Tubers.

Int J Mol Sci 2021 Nov 8;22(21). Epub 2021 Nov 8.

State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China.

Plants serve as a niche for the growth and proliferation of a diversity of microorganisms. Soil microorganisms, which closely interact with plants, are increasingly being recognized as factors important to plant health. In this study, we explored the use of high-throughput DNA sequencing of the fungal ITS and bacterial 16S for characterization of the fungal and bacterial microbiomes following biocontrol treatment (DT) with strain Bv17 relative to treatments without biocontrol (DC) during the potato growth cycle at three time points. A total of 5631 operational taxonomic units (OTUs) were identified from the 16S data, and 2236 OTUs were identified from the ITS data. The number of bacterial and fungal OTU in DT was higher than in DC and gradually increased during potato growth. In addition, indices such as Ace, Chao, Shannon, and Simpson were higher in DT than in DC, indicating greater richness and community diversity in soil following the biocontrol treatment. Additionally, the potato tuber yields improved without a measurable change in the bacterial communities following the strain Bv17 treatment. These results suggest that soil microbial communities in the rhizosphere are differentially affected by the biocontrol treatment while improving potato yield, providing a strong basis for biocontrol utilization in crop production.
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http://dx.doi.org/10.3390/ijms222112065DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8584837PMC
November 2021

Cytotoxic function of xylanase VdXyn4 in the plant vascular wilt pathogen Verticillium dahliae.

Plant Physiol 2021 09;187(1):409-429

Team of Crop Verticillium wilt, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China.

Phytopathogen xylanases play critical roles in pathogenesis, likely due to their ability to degrade plant structural barriers and manipulate host immunity. As an invader of plant xylem vessels, the fungus Verticillium dahliae is thought to deploy complex cell wall degrading enzymes. Comparative genomics analyses revealed that the V. dahliae genome encodes a family of six xylanases, each possessing a glycosyl hydrolase 11 domain, but the functions of these enzymes are undetermined. Characterizing gene deletion mutants revealed that only V. dahliae xylanase 4 (VdXyn4) degraded the plant cell wall and contributed to the virulence of V. dahliae. VdXyn4 displayed cytotoxic activity and induced a necrosis phenotype during the late stages of infection, leading to vein and petiole collapse that depended on the enzyme simultaneously localizing to nuclei and chloroplasts. The internalization of VdXyn4 was in conjunction with that of the plasma membrane complexLeucine-rich repeat (LRR)-receptor-like kinase suppressor of BIR1-1 (SOBIR1)/LRR-RLK BRI1-associated kinase-1 (BAK1), but we could not rule out the possibility that VdXyn4 may also act as an apoplastic effector. Immune signaling (in the SA-JA pathways) induced by VdXyn4 relative to that induced by known immunity effectors was substantially delayed. While cytotoxic activity could be partially suppressed by known effectors, they failed to impede necrosis in Nicotiana benthamiana. Thus, unlike typical effectors, cytotoxicity of VdXyn4 plays a crucial intracellular role at the late stages of V. dahliae infection and colonization, especially following pathogen entry into the xylem; this cytotoxic activity is likely conserved in the corresponding enzyme families in plant vascular pathogens.
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http://dx.doi.org/10.1093/plphys/kiab274DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8418393PMC
September 2021

Biological Characteristics of and Strains.

Int J Mol Sci 2021 Jul 1;22(13). Epub 2021 Jul 1.

Team of Crop Verticillium wilt, c/o State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China.

is a soil-borne plant pathogenic fungus that causes Verticillium wilt on hundreds of dicotyledonous plant species. is considered an asexually (clonal) reproducing fungus, although both mating type idiomorphs ( and ) are present, and is heterothallic. Most of the available information on strains, including their biology, pathology, and genomics comes from studies on isolates with the idiomorph, and thus little information is available on the strains in the literature. We therefore evaluated the growth responses of and   strains to various stimuli. Growth rates and melanin production in response to increased temperature, alkaline pH, light, and HO stress were higher in the strains than in the strains. In addition, the strains showed an enhanced ability to degrade complex polysaccharides, especially starch, pectin, and cellulose. Furthermore, several strains from both potato and sunflower showed increased virulence on their original hosts, relative to their counterparts. Thus, compared to strains, strains derive their potentially greater fitness from an increased capacity to adapt to their environment and exhibit higher virulence. These competitive advantages might explain the current abundance of strains relative to strains in the agricultural and sylvicultural ecosystems, and this study provides the baseline information on the two mating idiomorphs to study sexual reproduction in under natural and laboratory conditions.
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http://dx.doi.org/10.3390/ijms22137148DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8269371PMC
July 2021

Dynamics of Verticillium dahliae race 1 population under managed agricultural ecosystems.

BMC Biol 2021 06 25;19(1):131. Epub 2021 Jun 25.

Department of Plant Pathology, University of California, Davis, c/o U.S. Agricultural Research Station, Salinas, CA, USA.

Background: Plant pathogens and their hosts undergo adaptive changes in managed agricultural ecosystems, by overcoming host resistance, but the underlying genetic adaptations are difficult to determine in natural settings. Verticillium dahliae is a fungal pathogen that causes Verticillium wilt on many economically important crops including lettuce. We assessed the dynamics of changes in the V. dahliae genome under selection in a long-term field experiment.

Results: In this study, a field was fumigated before the Verticillium dahliae race 1 strain (VdLs.16) was introduced. A derivative 145-strain population was collected over a 6-year period from this field in which a seggregating population of lettuce derived from Vr1/vr1 parents were evaluated. We de novo sequenced the parental genome of VdLs.16 strain and resequenced the derivative strains to analyze the genetic variations that accumulate over time in the field cropped with lettuce. Population genomics analyses identified 2769 single-nucleotide polymorphisms (SNPs) and 750 insertion/deletions (In-Dels) in the 145 isolates compared with the parental genome. Sequence divergence was identified in the coding sequence regions of 378 genes and in the putative promoter regions of 604 genes. Five-hundred and nine SNPs/In-Dels were identified as fixed. The SNPs and In-Dels were significantly enriched in the transposon-rich, gene-sparse regions, and in those genes with functional roles in signaling and transcriptional regulation.

Conclusions: Under the managed ecosystem continuously cropped to lettuce, the local adaptation of V. dahliae evolves at a whole genome scale to accumulate SNPs/In-Dels nonrandomly in hypervariable regions that encode components of signal transduction and transcriptional regulation.
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http://dx.doi.org/10.1186/s12915-021-01061-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8235872PMC
June 2021

Key Insights and Research Prospects at the Dawn of the Population Genomics Era for .

Annu Rev Phytopathol 2021 08 23;59:31-51. Epub 2021 Apr 23.

Department of Plant Pathology, University of California, Davis, California 93905, USA; email:

The genomics era has ushered in exciting possibilities to examine the genetic bases that undergird the characteristic features of and other plant pathogens. In this review, we provide historical perspectives on some of the salient biological characteristics of , including its morphology, microsclerotia formation, host range, disease symptoms, vascular niche, reproduction, and population structure. The kaleidoscopic population structure of this pathogen is summarized, including different races of the pathogen, defoliating and nondefoliating phenotypes, vegetative compatibility groupings, and clonal populations. Where possible, we place the characteristic differences in the context of comparative and functional genomics analyses that have offered insights into population divergence within and the related species.Current challenges are highlighted along with some suggested future population genomics studies that will contribute to advancing our understanding of the population divergence in .
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http://dx.doi.org/10.1146/annurev-phyto-020620-121925DOI Listing
August 2021

Lysin Motif (LysM) Proteins: Interlinking Manipulation of Plant Immunity and Fungi.

Int J Mol Sci 2021 Mar 18;22(6). Epub 2021 Mar 18.

School of Life Sciences, Chongqing Normal University, Chongqing 401331, China.

The proteins with lysin motif (LysM) are carbohydrate-binding protein modules that play a critical role in the host-pathogen interactions. The plant LysM proteins mostly function as pattern recognition receptors (PRRs) that sense chitin to induce the plant's immunity. In contrast, fungal LysM blocks chitin sensing or signaling to inhibit chitin-induced host immunity. In this review, we provide historical perspectives on plant and fungal LysMs to demonstrate how these proteins are involved in the regulation of plant's immune response by microbes. Plants employ LysM proteins to recognize fungal chitins that are then degraded by plant chitinases to induce immunity. In contrast, fungal pathogens recruit LysM proteins to protect their cell wall from hydrolysis by plant chitinase to prevent activation of chitin-induced immunity. Uncovering this coevolutionary arms race in which LysM plays a pivotal role in manipulating facilitates a greater understanding of the mechanisms governing plant-fungus interactions.
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http://dx.doi.org/10.3390/ijms22063114DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8003243PMC
March 2021

Genome Sequence Data of and Idiomorphs from .

Phytopathology 2021 Sep 12;111(9):1686-1691. Epub 2021 Oct 12.

State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.

Though is an asexually reproducing fungus, it is considered heterothallic owing to the presence of only one of the two mating-type idiomorphs ( or ) in individual isolates. But sexual reproduction has never been observed either in nature or in the laboratory. All of the genomic information in the literature thus far has therefore come from studies on isolates carrying only the idiomorph. Herein, we sequenced and compared high-quality reference genomes of strain S011 and strain S023 obtained from the same sunflower field. The two genomic sequences displayed high synteny, and encoded similar number genes, a similarity especially notable among pathogenicity-related genes. Homolog analysis between these two genomes revealed that 80% of encoded genes are highly conserved (95% identity and coverage), but only 20% of the single copy genes were identical. These novel genome resources will support the analysis of the structure and function of the two idiomorphs and provide valuable tools to elucidate the evolution and potential mechanisms of sexual reproduction in .
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http://dx.doi.org/10.1094/PHYTO-01-21-0012-ADOI Listing
September 2021

Genome Sequence of Race 1 Isolate VdLs.16 From Lettuce.

Mol Plant Microbe Interact 2020 Nov 24;33(11):1265-1269. Epub 2020 Sep 24.

Team of Crop Verticillium wilt, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China.

is a widespread fungal pathogen that causes Verticillium wilt on many economically important crops and ornamentals worldwide. Populations of have been divided into two distinct races based upon differential host responses in tomato and lettuce. Recently, the contemporary race 2 isolates were further divided into an additional race in tomato. Herein, we provide a high-quality reference genome for the race 1 strain VdLs.16 isolated from lettuce in California, U.S.A. This resource will contribute to ongoing research that aims to elucidate the genetic basis of pathogenicity and population genomic diversity.
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http://dx.doi.org/10.1094/MPMI-04-20-0103-ADOI Listing
November 2020

Icariside II ameliorates myocardial ischemia and reperfusion injury by attenuating inflammation and apoptosis through the regulation of the PI3K/AKT signaling pathway.

Mol Med Rep 2020 Oct 31;22(4):3151-3160. Epub 2020 Jul 31.

Department of Emergency, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430014, P.R. China.

Icariside II (ICAII) is a bioflavonoid compound which has demonstrated anti‑oxidative, anti‑inflammatory and anti‑apoptotic biological activities. However, to the best of our knowledge, whether ICAII can alleviate myocardial ischemia and reperfusion injury (MIRI) remains unknown. The aim of the present study was to determine whether ICAII exerted a protective effect on MIRI and to investigate the potential underlying mechanism of action. A rat MIRI model was established by ligation of the left anterior descending coronary artery for 30 min, followed by a 24 h reperfusion. Pretreatment with ICAII with or without a PI3K/AKT inhibitor was administered at the beginning of reperfusion. Morphological and histological analyses were detected using hematoxylin and eosin staining; the infarct size was measured using Evans blue and 2,3,5‑triphenyltetrazolium chloride staining; and plasma levels of lactate dehydrogenase (LDH) and creatine kinase‑myocardial band (CK‑MB) were analyzed using commercialized assay kits. In addition, the cardiac function was evaluated by echocardiography and the levels of cardiomyocyte apoptosis were determined using a TUNEL staining. The protein expression levels of Bax, Bcl‑2, cleaved caspase‑3, interleukin‑6, tumor necrosis factor‑α, PI3K, phosphorylated (p)‑PI3K, AKT and p‑AKT were analyzed using western blotting analysis. ICAII significantly reduced the infarct size, decreased the release of LDH and CK‑MB and improved the cardiac function induced by IR injury. Moreover, ICAII pretreatment significantly inhibited myocardial apoptosis and the inflammatory response. ICAII also upregulated the expression levels of p‑PI3K and p‑AKT. However, the protective effects of ICAII were abolished by an inhibitor (LY294002) of the PI3K/AKT signaling pathway. In conclusion, the findings of the present study suggested that ICAII may mitigate MIRI by activating the PI3K/AKT signaling pathway.
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http://dx.doi.org/10.3892/mmr.2020.11396DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7453495PMC
October 2020

Impact of continuous low water stage on the breeding environment of Oncomelania hupensis: a case study of Poyang Lake area in China.

Infect Dis Poverty 2020 Jul 23;9(1):103. Epub 2020 Jul 23.

Jiangxi Provincial Institute of Parasitic Diseases, No.239,First Gaoxin Rd., Gaoxin District, 330096, Nanchang, Jiangxi Province, People's Republic of China.

Background: Oncomelania hupensis is the only intermediate host of Schistosoma japonicum and plays a decisive role in its transmission. The variation of water level greatly affects the reproduction and growth of snails. Therefore, in this paper, we analyze the variations of water level in the Poyang Lake region from 1993 to 2016 combined with satellite imagery to elucidate the evolution of the snail breeding environment.

Methods: By employing remote sensing data from 1993 to 2016 (April-June and September-November), the vegetation area of Poyang Lake and the vegetation area at different elevations were extracted and calculated. Moreover, the average daily water level data from the four hydrological stations (Hukou station, Xingzi station, Tangyin station and Kangshan station) which represent the typical state of Poyang Lake were collected from 1993 to 2016. The variance of the monthly mean water level, inundation time and the average area were analyzed by variance to find a significance level of α = 0.05.

Results: According to hydrological data before and after 2003, the average water level after 2003 is significantly lower than that before 2003 in Poyang Lake. After 2003, the time of inundateing the snail breeding period was later in April to June than that before 2003, while the time of wate-falling stage in September to November moved forward after 2003 than before 2003. Of them, the lowest water level affecting the breeding and growing period of O. hupensis in the northern part of Poyang Lake decreased from 11 m to 9 m. After 2003, the expansion of meadow area in the north part of Poyang Lake was mainly concentrated in the elevation of 9-11 m, and the newly increased infested-meadow in the lake area was mainly concentrated in the north part of Poyang Lake.

Conclusions: By comparing the change of water level characteristics in different parts of the Poyang Lake area as well as changes in meadow area before and after 2003, it is found that the water level changes mainly affect the snail breeding area in the northern part of Poyang Lake. The results are helpful for improving scientific measures for snail control in Jiangxi Province. This approach could also be applicible to Dongting Lake area and other lake areas affected by water level changes and can bring significant guidance for snail control in lake areas.
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http://dx.doi.org/10.1186/s40249-020-00720-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7376875PMC
July 2020

Screening of pesticide residues in Traditional Chinese Medicines using modified QuEChERS sample preparation procedure and LC-MS/MS analysis.

J Chromatogr B Analyt Technol Biomed Life Sci 2020 Sep 7;1152:122224. Epub 2020 Jun 7.

Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs/Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, PR China; State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, PR China. Electronic address:

A robust and high-throughput method was developed for the determination of 108 pesticide residues in Traditional Chinese Medicines (TCMs) simultaneously using a combination of UHPLC-MS/MS analysis and the modified QuEChERS method. Extraction was carried out in acetonitrile containing 0.75% (v/v) acetic acid with ultrasonication for 15 min; MgSO and C18 were used as the dispersive-solid phase extraction sorbents. The method exhibited good linearity (r > 0.9901), in addition to good selectivity, precision and repeatability. More than 92% of pesticides exhibited high rates or recovery in the 70-120% range. This method showed high sensitivity, with Limits of Quantitation in the 0.01-20 ng/mL range in Cortex Moutan, and 0.01-50 ng/mL in the other TCMs. The method was employed for the analysis of 39 real samples from different habitats, and pesticides were detected in 92.3% of the samples, with 26 pesticides being detected in these three TCMs. More than four pesticides were detected in a third of the samples. Among them, tebuconazole was detected in all the three TCMs with 0.22-22.02 μg/kg concentration, which was lower than the provisions in GB 2763-2019 (50 μg/kg). In addition, the paclobutrazol detection rate in Ophiopogon japonicus was 100%, and the detected concentrations of 9 samples exceeded the Maximum Residue Levels defined for vegetables (50 μg/kg). Considering there are no regulations that govern the limits of pesticide residues in the three TCMs in China, we recommend the acceleration of efforts to introduce appropriate regulations.
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http://dx.doi.org/10.1016/j.jchromb.2020.122224DOI Listing
September 2020

Functional analyses of small secreted cysteine-rich proteins identified candidate effectors in Verticillium dahliae.

Mol Plant Pathol 2020 05 10;21(5):667-685. Epub 2020 Mar 10.

Laboratory of Cotton Disease, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, China.

Secreted small cysteine-rich proteins (SCPs) play a critical role in modulating host immunity in plant-pathogen interactions. Bioinformatic analyses showed that the fungal pathogen Verticillium dahliae encodes more than 100 VdSCPs, but their roles in host-pathogen interactions have not been fully characterized. Transient expression of 123 VdSCP-encoding genes in Nicotiana benthamiana identified three candidate genes involved in host-pathogen interactions. The expression of these three proteins, VdSCP27, VdSCP113, and VdSCP126, in N. benthamiana resulted in cell death accompanied by a reactive oxygen species burst, callose deposition, and induction of defence genes. The three VdSCPs mainly localized to the periphery of the cell. BAK1 and SOBIR1 (associated with receptor-like protein) were required for the immunity triggered by these three VdSCPs in N. benthamiana. Site-directed mutagenesis showed that cysteine residues that form disulphide bonds are essential for the functioning of VdSCP126, but not VdSCP27 and VdSCP113. VdSCP27, VdSCP113, and VdSCP126 individually are not essential for V. dahliae infection of N. benthamiana and Gossypium hirsutum, although there was a significant reduction of virulence on N. benthamiana and G. hirsutum when inoculated with the VdSCP27/VdSCP126 double deletion strain. These results illustrate that the SCPs play a critical role in the V. dahliae-plant interaction via an intrinsic virulence function and suppress immunity following infection.
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http://dx.doi.org/10.1111/mpp.12921DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7170778PMC
May 2020

The Verticillium dahliae Sho1-MAPK pathway regulates melanin biosynthesis and is required for cotton infection.

Environ Microbiol 2019 12 24;21(12):4852-4874. Epub 2019 Nov 24.

Laboratory of Cotton Disease, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.

Verticillium dahliae is a soil-borne fungus that causes vascular wilt on numerous plants worldwide. The fungus survives in the soil for up to 14 years by producing melanized microsclerotia. The protective function of melanin in abiotic stresses is well documented. Here, we found that the V. dahliae tetraspan transmembrane protein VdSho1, a homolog of the Saccharomyces cerevisiae Sho1, acts as an osmosensor, and is required for plant penetration and melanin biosynthesis. The deletion mutant ΔSho1 was incubated on a cellophane membrane substrate that mimics the plant epidermis, revealing that the penetration of ΔSho1 strain was reduced compared to the wild-type strain. Furthermore, VdSho1 regulates melanin biosynthesis by a signalling mechanism requiring a kinase-kinase signalling module of Vst50-Vst11-Vst7. Strains, ΔVst50, ΔVst7 and ΔVst11 also displayed defective penetration and melanin production like the ΔSho1 strain. Defects in penetration and melanin production in ΔSho1 were restored by overexpression of Vst50, suggesting that Vst50 lies downstream of VdSho1 in the regulatory pathway governing penetration and melanin biosynthesis. Data analyses revealed that the transmembrane portion of VdSho1 was essential for both membrane penetration and melanin production. This study demonstrates that Vst50-Vst11-Vst7 module regulates VdSho1-mediated plant penetration and melanin production in V. dahliae, contributing to virulence.
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http://dx.doi.org/10.1111/1462-2920.14846DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6916341PMC
December 2019

Diversity of culture-independent bacteria and antimicrobial activity of culturable endophytic bacteria isolated from different Dendrobium stems.

Sci Rep 2019 07 17;9(1):10389. Epub 2019 Jul 17.

Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, China.

Dendrobium is known for its pharmacological actions including anti-cancer effect, anti-fatigue effect, gastric ulcer protective effect, and so on. At present, only studies on endophytic fungi of Dendrobium affecting the metabolites of host plants have been reported, very little research has been done on endophytic bacteria. In this study, we have demonstrated the great diversity of endophytic bacteria in 6 Dendrobium samples from different origins and cultivars. According to the results of the culture-independent method, the endophytic bacterial community in Dendrobium stems showed obvious different in the 6 samples and was influenced by origin and cultivar. Some bacteria including Ralstonia, Comamonas and Lelliottia were first detected in Dendrobium in this study. Based on the culture-dependent method, a total of 165 cultivable endophytic bacteria isolates were isolated from the sterilized Dendrobium stems, and were classified into 43 species according to the 16S rRNA gene sequence analysis. Moreover, 14 of the 43 strains showed antimicrobial activity against phytopathogen using the Kirby-Bauer method. Strain NA-HTong-7 (Bacillus megaterium, 99.12%) showed the highest antimicrobial activity. This study was the first comprehensive study on endophytic bacteria of Dendrobium from different origins and cultivars, which provides new insights into the endophytic bacteria from Dendrobium.
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http://dx.doi.org/10.1038/s41598-019-46863-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6637234PMC
July 2019

The Gossypium hirsutum TIR-NBS-LRR gene GhDSC1 mediates resistance against Verticillium wilt.

Mol Plant Pathol 2019 06 8;20(6):857-876. Epub 2019 Apr 8.

Laboratory of Cotton Disease, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.

Improving genetic resistance is a preferred method to manage Verticillium wilt of cotton and other hosts. Identifying host resistance is difficult because of the dearth of resistance genes against this pathogen. Previously, a novel candidate gene involved in Verticillium wilt resistance was identified by a genome-wide association study using a panel of Gossypium hirsutum accessions. In this study, we cloned the candidate resistance gene from cotton that encodes a protein sharing homology with the TIR-NBS-LRR receptor-like defence protein DSC1 in Arabidopsis thaliana (hereafter named GhDSC1). GhDSC1 expressed at higher levels in response to Verticillium wilt and jasmonic acid (JA) treatment in resistant cotton cultivars as compared to susceptible cultivars and its product was localized to nucleus. The transfer of GhDSC1 to Arabidopsis conferred Verticillium resistance in an A. thaliana dsc1 mutant. This resistance response was associated with reactive oxygen species (ROS) accumulation and increased expression of JA-signalling-related genes. Furthermore, the expression of GhDSC1 in response to Verticillium wilt and JA signalling in A. thaliana displayed expression patterns similar to GhCAMTA3 in cotton under identical conditions, suggesting a coordinated DSC1 and CAMTA3 response in A. thaliana to Verticillium wilt. Analyses of GhDSC1 sequence polymorphism revealed a single nucleotide polymorphism (SNP) difference between resistant and susceptible cotton accessions, within the P-loop motif encoded by GhDSC1. This SNP difference causes ineffective activation of defence response in susceptible cultivars. These results demonstrated that GhDSC1 confers Verticillium resistance in the model plant system of A. thaliana, and therefore represents a suitable candidate for the genetic engineering of Verticillium wilt resistance in cotton.
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http://dx.doi.org/10.1111/mpp.12797DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6637886PMC
June 2019

Population genomics demystifies the defoliation phenotype in the plant pathogen Verticillium dahliae.

New Phytol 2019 04 25;222(2):1012-1029. Epub 2019 Feb 25.

Laboratory of Crop Verticillium Wilt, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.

Verticillium dahliae is a broad host-range pathogen that causes vascular wilts in plants. Interactions between three hosts and specific V. dahliae genotypes result in severe defoliation. The underlying mechanisms of defoliation are unresolved. Genome resequencing, gene deletion and complementation, gene expression analysis, sequence divergence, defoliating phenotype identification, virulence analysis, and quantification of V. dahliae secondary metabolites were performed. Population genomics previously revealed that G-LSR2 was horizontally transferred from the fungus Fusarium oxysporum f. sp. vasinfectum to V. dahliae and is exclusively found in the genomes of defoliating (D) strains. Deletion of seven genes within G-LSR2, designated as VdDf genes, produced the nondefoliation phenotype on cotton, olive, and okra but complementation of two genes restored the defoliation phenotype. Genes VdDf5 and VdDf6 associated with defoliation shared homology with polyketide synthases involved in secondary metabolism, whereas VdDf7 shared homology with proteins involved in the biosynthesis of N-lauroylethanolamine (N-acylethanolamine (NAE) 12:0), a compound that induces defoliation. NAE overbiosynthesis by D strains also appears to disrupt NAE metabolism in cotton by inducing overexpression of fatty acid amide hydrolase. The VdDfs modulate the synthesis and overproduction of secondary metabolites, such as NAE 12:0, that cause defoliation either by altering abscisic acid sensitivity, hormone disruption, or sensitivity to the pathogen.
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http://dx.doi.org/10.1111/nph.15672DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6594092PMC
April 2019

Genome-Wide Identification and Functional Analyses of the CRK Gene Family in Cotton Reveals Confers Verticillium Wilt Resistance in .

Front Plant Sci 2018 11;9:1266. Epub 2018 Sep 11.

Laboratory of Cotton Disease, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, China.

Cysteine-rich receptor-like kinases () are a large subfamily of plant receptor-like kinases that play a critical role in disease resistance in plants. However, knowledge about the gene family in cotton and its function against Verticillium wilt (VW), a destructive disease caused by that significantly reduces cotton yields is lacking. In this study, we identified a total of 30 typical in a genome (). Eleven of these (>30%) are located on the A06 and D06 chromosomes, and 18 consisted of 9 paralogous pairs encoded in the A and D subgenomes. Phylogenetic analysis showed that the could be classified into four broad groups, the expansion of which has probably been driven by tandem duplication. Gene expression profiling of the in resistant and susceptible cotton cultivars revealed that a phylogenetic cluster of nine of the genes were up-regulated in response to infection. Virus-induced gene silencing of each of these nine independently revealed that the silencing of was sufficient to compromise VW resistance in . GbCRK18 expression could be induced by infection or jasmonic acid, and displayed plasma membrane localization. Therefore, our expression analyses indicated that the gene family is differentially regulated in response to Verticillium infection, while gene silencing experiments revealed that in particular confers VW resistance in .
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http://dx.doi.org/10.3389/fpls.2018.01266DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6141769PMC
September 2018

Heterologous Expression of the Cotton NBS-LRR Gene Enhances Verticillium Wilt Resistance in .

Front Plant Sci 2018 6;9:119. Epub 2018 Feb 6.

Laboratory of Cotton Disease, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, c/o Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture, Beijing, China.

Verticillium wilt caused by results in severe losses in cotton, and is economically the most destructive disease of this crop. Improving genetic resistance is the cleanest and least expensive option to manage Verticillium wilt. Previously, we identified the island cotton NBS-LRR-encoding gene that confers resistance to the highly virulent isolate Vd991. In this study, we expressed cotton in the heterologous system of and investigated the defense response mediated by GbaNA1 following inoculations with . Heterologous expression of conferred Verticillium wilt resistance in . Moreover, overexpression of enabled recovery of the resistance phenotype of mutants that had lost the function of ortholog gene. Investigations of the defense response in showed that the reactive oxygen species (ROS) production and the expression of genes associated with the ethylene signaling pathway were enhanced significantly following overexpression of . Intriguingly, overexpression of the ortholog from () in did not induce the defense response of ROS production due to the premature termination of , which lacks the encoded NB-ARC and LRR motifs. therefore confers Verticillium wilt resistance in by the activation of ROS production and ethylene signaling. These results demonstrate the functional conservation of the NBS-LRR-encoding in a heterologous system, and the mechanism of this resistance, both of which may prove valuable in incorporating -mediated resistance into other plant species.
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http://dx.doi.org/10.3389/fpls.2018.00119DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5808209PMC
February 2018

SNARE-Encoding Genes VdSec22 and VdSso1 Mediate Protein Secretion Required for Full Virulence in Verticillium dahliae.

Mol Plant Microbe Interact 2018 06 4;31(6):651-664. Epub 2018 May 4.

1 Laboratory of Cotton Disease, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.

Proteins that mediate cellular and subcellular membrane fusion are key factors in vesicular trafficking in all eukaryotic cells, including the secretion and transport of plant pathogen virulence factors. In this study, we identified vesicle-fusion components that included 22 soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs), four Sec1/Munc18 (SM) family proteins, and 10 Rab GTPases encoded in the genome of the vascular wilt pathogen Verticillium dahliae Vd991. Targeted deletion of two SNARE-encoding genes in V. dahliae, VdSec22 and VdSso1, significantly reduced virulence of both mutants on cotton, relative to the wild-type Vd991 strain. Comparative analyses of the secreted protein content (exoproteome) revealed that many enzymes involved in carbohydrate hydrolysis were regulated by VdSec22 or VdSso1. Consistent with a role of these enzymes in plant cell-wall degradation, pectin, cellulose, and xylan utilization were reduced in the VdSec22 or VdSso1 mutant strains along with a loss of exoproteome cytotoxic activity on cotton leaves. Comparisons with a pathogenicity-related exoproteome revealed that several known virulence factors were not regulated by VdSec22 or VdSso1, but some of the proteins regulated by VdSec22 or VdSso1 displayed different characteristics, including the lack of a typical signal peptide, suggesting that V. dahliae employs more than one secretory route to transport proteins to extracellular sites during infection.
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http://dx.doi.org/10.1094/MPMI-12-17-0289-RDOI Listing
June 2018

Chitosan nanoparticles having higher degree of acetylation induce resistance against pearl millet downy mildew through nitric oxide generation.

Sci Rep 2018 02 6;8(1):2485. Epub 2018 Feb 6.

International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, 502324, Telangana, India.

Downy mildew of pearl millet caused by the biotrophic oomycete Sclerospora graminicola is the most devastating disease which impairs pearl millet production causing huge yield and monetary losses. Chitosan nanoparticles (CNP) were synthesized from low molecular weight chitosan having higher degree of acetylation was evaluated for their efficacy against downy mildew disease of pearl millet caused by Sclerospora graminicola. Laboratory studies showed that CNP seed treatment significantly enhanced pearl millet seed germination percentage and seedling vigor compared to the control. Seed treatment with CNP induced systemic and durable resistance and showed significant downy mildew protection under greenhouse conditions in comparison to the untreated control. Seed treatment with CNP showed changes in gene expression profiles wherein expression of genes of phenylalanine ammonia lyase, peroxidase, polyphenoloxidase, catalase and superoxide dismutase were highly upregulated. CNP treatment resulted in earlier and higher expression of the pathogenesis related proteins PR1 and PR5. Downy mildew protective effect offered by CNP was found to be modulated by nitric oxide and treatment with CNP along with NO inhibitors cPTIO completely abolished the gene expression of defense enzymes and PR proteins. Further, comparative analysis of CNP with Chitosan revealed that the very small dosage of CNP performed at par with recommended dose of Chitosan for downy mildew management.
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http://dx.doi.org/10.1038/s41598-017-19016-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5802724PMC
February 2018

[Clinical study of simultaneous implantation in maxillary molar area after bone graft in patients with residual alveolar bone height<3 mm].

Shanghai Kou Qiang Yi Xue 2017 Jun;26(3):290-292

Department of Stomatology, Zhongshan Hospital of Fudan University. Shanghai 200032, China.

Purpose: To evaluate the clinical effect of maxillary sinus floor elevation and simultaneous implant in patients with residual alveolar bone height <3 mm in the posterior maxillary sinus area.

Methods: From April 1, 2012 to December 31, 2015, 56 patients with lost maxillary posterior teeth and residual alveolar bone height <3 mm were enrolled in this study. During operation, maxillary sinus floor elevation was performed and implants were placed simultaneously. Patients were followed up for 3, 6 and 12 months (range: 6-12 months) to analyze and evaluate the postoperative healing effect.

Results: A total of 52 implants were placed in 38 patients. During the follow-up period, all patients had good osterintegration of the implants and the surrounding bony tissues. Efficient mastication was obtained. The color and shape of gingiva returned to normal. No complications occurred. The surgical success rate was 100%.

Conclusions: For patients with residual alveolar bone height <3 mm, maxillary sinus floor elevation and simultaneous implant in patients can also obtain good therapeutic effect.
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June 2017

Comparative genomics reveals cotton-specific virulence factors in flexible genomic regions in Verticillium dahliae and evidence of horizontal gene transfer from Fusarium.

New Phytol 2018 01 30;217(2):756-770. Epub 2017 Oct 30.

Laboratory of Cotton Disease, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.

Verticillium dahliae isolates are most virulent on the host from which they were originally isolated. Mechanisms underlying these dominant host adaptations are currently unknown. We sequenced the genome of V. dahliae Vd991, which is highly virulent on its original host, cotton, and performed comparisons with the reference genomes of JR2 (from tomato) and VdLs.17 (from lettuce). Pathogenicity-related factor prediction, orthology and multigene family classification, transcriptome analyses, phylogenetic analyses, and pathogenicity experiments were performed. The Vd991 genome harbored several exclusive, lineage-specific (LS) genes within LS regions (LSRs). Deletion mutants of the seven genes within one LSR (G-LSR2) in Vd991 were less virulent only on cotton. Integration of G-LSR2 genes individually into JR2 and VdLs.17 resulted in significantly enhanced virulence on cotton but did not affect virulence on tomato or lettuce. Transcription levels of the seven LS genes in Vd991 were higher during the early stages of cotton infection, as compared with other hosts. Phylogenetic analyses suggested that G-LSR2 was acquired from Fusarium oxysporum f. sp. vasinfectum through horizontal gene transfer. Our results provide evidence that horizontal gene transfer from Fusarium to Vd991 contributed significantly to its adaptation to cotton and may represent a significant mechanism in the evolution of an asexual plant pathogen.
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http://dx.doi.org/10.1111/nph.14861DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5765495PMC
January 2018

A Verticillium dahliae Extracellular Cutinase Modulates Plant Immune Responses.

Mol Plant Microbe Interact 2018 Feb 20;31(2):260-273. Epub 2017 Dec 20.

1 Laboratory of Cotton Disease, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, 100193, China; and.

Cutinases have been implicated as important enzymes during the process of fungal infection of aerial plant organs. The function of cutinases in the disease cycle of fungal pathogens that invade plants through the roots has been less studied. Here, functional analysis of 13 cutinase (carbohydrate esterase family 5 domain-containing) genes (VdCUTs) in the highly virulent vascular wilt pathogen Verticillium dahliae Vd991 was performed. Significant sequence divergence in cutinase family members was observed in the genome of V. dahliae Vd991. Functional analyses demonstrated that only VdCUT11, as purified protein, induced cell death and triggered defense responses in Nicotiana benthamiana, cotton, and tomato plants. Virus-induced gene silencing showed that VdCUT11 induces plant defense responses in Nicotiana benthamania in a BAK1 and SOBIR-dependent manner. Furthermore, coinfiltration assays revealed that the carbohydrate-binding module family 1 protein (VdCBM1) suppressed VdCUT11-induced cell death and other defense responses in N. benthamiana. Targeted deletion of VdCUT11 in V. dahliae significantly compromised virulence on cotton plants. The cutinase VdCUT11 is an important secreted enzyme and virulence factor that elicits plant defense responses in the absence of VdCBM1.
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http://dx.doi.org/10.1094/MPMI-06-17-0136-RDOI Listing
February 2018
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