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Yuanchao Wang - One of the best experts on this subject based on the ideXlab platform.
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Phytophthora sojae and soybean isoflavones a model to study zoospore chemotaxis
Physiological and Molecular Plant Pathology, 2015Co-Authors: Chenlei Hua, Xinyu Yang, Yuanchao WangAbstract:Abstract The ability of sensing the signals from hosts, aggregating, and searching for proper sites of invasion is crucial for many soil-borne plant pathogens. One of these is Phytophthora sojae that specifically infects soybean and causes severe yield loss. In the field P. sojae zoospores attracted to soybean exudates isoflavones is an essential step for early infection. Recent studies based on genome mining and gene silencing technologies have shown that this special zoospore behavior relies on G-protein mediated signaling pathways. This review is to summarize researches on P. sojae functional genomics related to G-protein signaling and briefly describe the molecular mechanism of P. sojae zoospore chemotaxis to root exudates, especially isoflavones.
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the Phytophthora sojae avr1d gene encodes an rxlr deer effector with presence and absence polymorphisms among pathogen strains
Molecular Plant-microbe Interactions, 2013Co-Authors: Weixiao Yin, Suomeng Dong, Xiaobo Zheng, Yachun Lin, Luchong Zhai, Yuanchao WangAbstract:Soybean root and stem rot is caused by the oomycete pathogen Phytophthora sojae. The interaction between P. sojae and soybean fits the “gene-for-gene” hypothesis. Although more than 10 P. sojae avirulence (Avr) effectors have been genetically identified, nearly half of genetically defined avr genes have been cloned. In a previous bioinformatic and global transcriptional analysis, we identified a P. sojae RxLR effector, Avr1d, which was 125 amino acids in length. Mapping data demonstrated that Avr1d presence or absence in the genome was co-segregated with the Avr1d avirulence phenotype in F2 populations. Transient expression of the Avr1d gene using co-bombardment in soybean isogenic lines revealed that this gene triggered a hypersensitive response (HR) in the presence of Rps1d. Sequencing of Avr1d genes in different P. sojae strains revealed two Avr1d alleles. Although polymorphic, the two Avr1d alleles could trigger Rps1d-mediated HR. P. sojae strains carrying either of the alleles were avirulent on Rps1d...
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two rxlr avirulence genes in Phytophthora sojae determine soybean rps1k mediated disease resistance
Molecular Plant-microbe Interactions, 2013Co-Authors: Tianqiao Song, Shiv D Kale, Yuanchao Wang, Daolong Dou, Li Liu, Danyu Shen, Felipe D Arredondo, Brett M. TylerAbstract:Resistance to Phytophthora sojae (Rps) genes have been widely used in soybean against root and stem rot diseases caused by this oomycete. Among 15 known soybean Rps genes, Rps1k has been the most widely used in the past four decades. Here, we show that the products of two distinct but closely linked RxLR effector genes are detected by Rps1k-containing plants, resulting in disease resistance. One of the genes is Avr1b-1, that confers avirulence in the presence of Rps1b. Three lines of evidence, including overexpression and gene silencing of Avr1b-1 in stable P. sojae transformants, as well as transient expression of this gene in soybean, indicated that Avr1b could trigger an Rps1k-mediated defense response. Some isolates of P. sojae that do not express Avr1b are nevertheless unable to infect Rps1k plants. In those isolates, we identified a second RxLR effector gene (designated Avr1k), located 5 kb away from Avr1b-1. Silencing or overexpression of Avr1k in P. sojae stable transformants resulted in the loss or gain, respectively, of the avirulence phenotype in the presence of Rps1k. Only isolates of P. sojae with mutant alleles of both Avr1b-1 and Avr1k could evade perception by the soybean plants carrying Rps1k.
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the rxlr effector avh241 from Phytophthora sojae requires plasma membrane localization to induce plant cell death
New Phytologist, 2012Co-Authors: Junli Tang, Qunqing Wang, Suomeng Dong, Kai Tao, Xiaobo Zheng, Xinyu Yang, Shuyi Duan, Yuanchao WangAbstract:• The Phytophthora sojae genome encodes hundreds of RxLR effectors predicted to manipulate various plant defense responses, but the molecular mechanisms involved are largely unknown. Here we have characterized in detail the P. sojae RxLR effector Avh241. • To determine the function and localization of Avh241, we transiently expressed it on different plants. Silencing of Avh241 in P. sojae, we determined its virulence during infection. Through the assay of promoting infection by Phytophthora capsici to Nicotiana benthamiana, we further confirmed this virulence role. • Avh241 induced cell death in several different plants and localized to the plant plasma membrane. An N-terminal motif within Avh241 was important for membrane localization and cell death-inducing activity. Two mitogen-activated protein kinases, NbMEK2 and NbWIPK, were required for the cell death triggered by Avh241 in N. benthamiana. Avh241 was important for the pathogen's full virulence on soybean. Avh241 could also promote infection by P. capsici and the membrane localization motif was not required to promote infection. • This work suggests that Avh241 interacts with the plant immune system via at least two different mechanisms, one recognized by plants dependent on subcellular localization and one promoting infection independent on membrane localization.
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development of a loop mediated isothermal amplification assay for detection of Phytophthora sojae
Fems Microbiology Letters, 2012Co-Authors: Tingting Dai, Suomeng Dong, Yuanchao Wang, Xiaobo ZhengAbstract:Phytophthora sojae is a devastating pathogen that causes soybean Phytophthora root rot. This study reports the development of a loop-mediated isothermal amplification (LAMP) assay targeting the A3aPro element for visual detection of P. sojae . The A3aPro -LAMP assay efficiently amplified the target element in < 80 min at 64 °C and was evaluated for specificity and sensitivity. The specificity was evaluated against P. sojae , Phytophthora spp., Pythium spp., and true fungi isolates. Magnesium pyrophosphate resulting from the LAMP of P. sojae could be detected by real-time measurement of turbidity. Phytophthora sojae DNA products were visualized as a ladder-like banding pattern on 2% gel electrophoresis. A positive colour (sky blue) was only observed in the presence of P. sojae with the addition of hydroxynaphthol blue prior to amplification, whereas none of other isolates showed a colour change. The detection limit of the A3aPro -specific LAMP assay for P. sojae was 10 pg µL−1 of genomic DNA per reaction. The assay also detected P. sojae from diseased soybean tissues and residues. These results suggest that the A3aPro -LAMP assay reported here can be used for the visual detection of P. sojae in plants and production fields.
Anne E Dorrance - One of the best experts on this subject based on the ideXlab platform.
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auxin profiling and gmpin expression in Phytophthora sojae soybean root interactions
Phytopathology, 2020Co-Authors: Anna K Stasko, Amine Batnini, Carlos Bolanoscarriel, Jinshan Ella Lin, Yun Lin, Joshua J Blakeslee, Anne E DorranceAbstract:Auxin (indole-3-acetic acid, IAA) has been implicated as a susceptibility factor in both beneficial and pathogenic molecular plant-microbe interactions. Previous studies have identified a large number of auxin-related genes underlying quantitative disease resistance loci (QDRLs) for Phytophthora sojae. Thus, we hypothesized that auxin may be involved the P. sojae-soybean interaction. The levels of IAA and related metabolites were measured in mycelia and media supernatant as well as in mock and inoculated soybean roots in a time course assay. The expression of 11 soybean Pin-formed (GmPIN) auxin efflux transporter genes was also examined. Tryptophan, an auxin precursor, was detected in the P. sojae mycelia and media supernatant. During colonization of roots, levels of IAA and related metabolites were significantly higher in both moderately resistant Conrad and moderately susceptible Sloan inoculated roots compared with mock controls at 48 h postinoculation (hpi) in one experiment and at 72 hpi in a second, with Sloan accumulating higher levels of the auxin catabolite IAA-Ala than Conrad. Additionally, one GmPIN at 24 hpi, one at 48 hpi, and three at 72 hpi had higher expression in inoculated compared with the mock control roots in Conrad. The ability of resistant cultivars to cope with auxin accumulation may play an important role in quantitative disease resistance. Levels of jasmonic acid (JA), another plant hormone associated with defense responses, were also higher in inoculated roots at these same time points, suggesting that JA also plays a role during the later stages of infection.
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testing methods and statistical models of genomic prediction for quantitative disease resistance to Phytophthora sojae in soybean glycine max l merr germplasm collections
Theoretical and Applied Genetics, 2020Co-Authors: William Rolling, Anne E Dorrance, Leah K MchaleAbstract:Genomic prediction of quantitative resistance toward Phytophthora sojae indicated that genomic selection may increase breeding efficiency. Statistical model and marker set had minimal effect on genomic prediction with > 1000 markers. Quantitative disease resistance (QDR) toward Phytophthora sojae in soybean is a complex trait controlled by many small-effect loci throughout the genome. Along with the technical and rate-limiting challenges of phenotyping resistance to a root pathogen, the trait complexity can limit breeding efficiency. However, the application of genomic prediction to traits with complex genetic architecture, such as QDR toward P. sojae, is likely to improve breeding efficiency. We provide a novel example of genomic prediction by measuring QDR to P. sojae in two diverse panels of more than 450 plant introductions (PIs) that had previously been genotyped with the SoySNP50K chip. This research was completed in a collection of diverse germplasm and contributes to both an initial assessment of genomic prediction performance and characterization of the soybean germplasm collection. We tested six statistical models used for genomic prediction including Bayesian Ridge Regression; Bayesian LASSO; Bayes A, B, C; and reproducing kernel Hilbert spaces. We also tested how the number and distribution of SNPs included in genomic prediction altered predictive ability by varying the number of markers from less than 50 to more than 34,000 SNPs, including SNPs based on sequential sampling, random sampling, or selections from association analyses. Predictive ability was relatively independent of statistical model and marker distribution, with a diminishing return when more than 1000 SNPs were included in genomic prediction. This work estimated relative efficiency per breeding cycle between 0.57 and 0.83, which may improve the genetic gain for P. sojae QDR in soybean breeding programs.
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management of Phytophthora sojae of soybean a review and future perspectives
Canadian Journal of Plant Pathology-revue Canadienne De Phytopathologie, 2018Co-Authors: Anne E DorranceAbstract:Phytophthora sojae Kaufmann & Gerdemann has been a yield limiting factor for more than 60 years on soybean (Glycine max L.) in Ohio and other regions where soils are poorly drained. Soybean is the ...
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pathotype diversity of Phytophthora sojae in eleven states in the united states
Plant Disease, 2016Co-Authors: Anne E Dorrance, Alison E. Robertson, J E Kurle, Carl A Bradley, Loren J Giesler, Kiersten A Wise, Vergel C ConcibidoAbstract:Pathotype diversity of Phytophthora sojae was assessed in 11 states in the United States during 2012 and 2013. Isolates of P. sojae were recovered from 202 fields, either from soil samples using a soybean seedling bioassay or by isolation from symptomatic plants. Each isolate was inoculated directly onto 12 soybean differentials; no Rps gene or Rps 1a, 1b, 1c, 1k, 3a, 3b, 3c, 4, 6, 7, or 8. There were 213 unique virulence pathotypes identified among the 873 isolates collected. None of the Rps genes were effective against all the isolates collected but Rps6 and Rps8 were effective against the majority of isolates collected in the northern regions of the sampled area. Virulence toward Rps1a, 1b, 1c, and 1k ranged from 36 to 100% of isolates collected in each state, while virulence to Rps6 and Rps8 was less than 36 and 10%, respectively. Depending on the state, the effectiveness of Rps3a ranged from totally effective to susceptible to more than 40% of the isolates. Pathotype complexity has increased in popul...
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population structure among and within iowa missouri ohio and south dakota populations of Phytophthora sojae
Plant Disease, 2016Co-Authors: Silvina Stewart, Alison E. Robertson, D Wickramasinghe, Martin A Draper, Andrew P Michel, Anne E DorranceAbstract:Phytophthora root and stem rot, caused by Phytophthora sojae, is an economically important disease of soybean throughout the Midwestern United States. This disease has been successfully managed with resistance (Rps) genes; however, pathogen populations throughout the Midwest have developed virulence to many Rps genes, including those that have not been deployed. To gain a better understanding of the processes that influence P. sojae evolution, the population genetic structure was compared among populations using one isolate collected from 17, 33, and 20 fields in Iowa, Ohio, and South Dakota, respectively, as well as multiple isolates from individual fields in Iowa, Ohio, and Missouri. Genotypic diversity was measured using 21 polymorphic microsatellite (simple-sequence repeat) markers. and pathotype diversity using 15 soybean differentials. For all but three of the populations with low sample size, there was a high level of pathotype diversity and a low to moderate level of genotypic diversity among the ...
Daolong Dou - One of the best experts on this subject based on the ideXlab platform.
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PsGRASP, a Golgi Reassembly Stacking Protein in Phytophthora sojae, Is Required for Mycelial Growth, Stress Responses, and Plant Infection
'Frontiers Media SA', 2021Co-Authors: Yong Pei, Xiong Zhang, Huijun Qiao, Danyu Shen, Hao Peng, Daolong DouAbstract:Golgi reassembly stacking proteins (GRASPs) play important roles in Golgi structure formation, ER stress response, and unconventional secretion in eukaryotic cells. However, GRASP functions in oomycetes haven’t been adequately characterized. Here, we report the identification and functional analysis of PsGRASP, a GRASP-encoding gene from the soybean-infecting oomycete Phytophthora sojae. Transcriptional profiling showed that PsGRASP expression is up-regulated at the infection stages. PsGRASP knockout mutants were created using the CRISPR/Cas9 system. These mutants exhibited impaired vegetative growth, zoospore release and virulence. PsGRASP was involved ER stress responses and altered laccase activity. Our work suggests that PsGRASP is crucial for P. sojae development and pathogenicity
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Phytophthora sojae effector pscrn70 suppresses plant defenses in nicotiana benthamiana
PLOS ONE, 2014Co-Authors: Nasir Rajput, Meixiang Zhang, Tingli Liu, Li Liu, Joseph Juma Mafurah, Daolong DouAbstract:Phytophthora sojae, an oomycete pathogen, produces a large number of effector proteins that enter into host cells. The Crinklers (Crinkling and Necrosis, CRN) are cytoplasmic effectors that are conserved in oomycete pathogens and their encoding genes are highly expressed at the infective stages in P. sojae. However, their roles in pathogenesis are largely unknown. Here, we functionally characterized an effector PsCRN70 by transiently and stably overexpressing it in Nicotiana benthamiana. We demonstrated that PsCRN70 was localized to the plant cell nucleus and suppressed cell death elicited by all the tested cell death-inducing proteins, including BAX, PsAvh241, PsCRN63, PsojNIP and R3a/Avr3a. Overexpression of the PsCRN70 gene in N. benthamiana enhanced susceptibility to P. parasitica. The H2O2 accumulation in the PsCRN70-transgenic plants was reduced compared to the GFP-lines. The transcriptional levels of the defense-associated genes, including PR1b, PR2b, ERF1 and LOX, were also down-regulated in the PsCRN70-transgenic lines. Our results suggest that PsCRN70 may function as a universal suppressor of the cell death induced by many elicitors, the host H2O2 accumulation and the expression of defense-associated genes, and therefore promotes pathogen infection.
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two cytoplasmic effectors of Phytophthora sojae regulate plant cell death via interactions with plant catalases
Plant Physiology, 2014Co-Authors: Meixiang Zhang, Tingli Liu, Li Liu, Danyu Shen, Ye Zhu, Peihan Liu, Jianmin Zhou, Daolong DouAbstract:Plant pathogenic oomycetes, such as Phytophthora sojae, secrete an arsenal of host cytoplasmic effectors to promote infection. We have shown previously that P. sojae PsCRN63 (for crinkling- and necrosis-inducing proteins) induces programmed cell death (PCD) while PsCRN115 blocks PCD in planta; however, they are jointly required for full pathogenesis. Here, we find that PsCRN63 alone or PsCRN63 and PsCRN115 together might suppress the immune responses of Nicotiana benthamiana and demonstrate that these two cytoplasmic effectors interact with catalases from N. benthamiana and soybean (Glycine max). Transient expression of PsCRN63 increases hydrogen peroxide (H2O2) accumulation, whereas PsCRN115 suppresses this process. Transient overexpression of NbCAT1 (for N. benthamiana CATALASE1) or GmCAT1 specifically alleviates PsCRN63-induced PCD. Suppression of the PsCRN63-induced PCD by PsCRN115 is compromised when catalases are silenced in N. benthamiana. Interestingly, the NbCAT1 is recruited into the plant nucleus in the presence of PsCRN63 or PsCRN115; NbCAT1 and GmCAT1 are destabilized when PsCRN63 is coexpressed, and PsCRN115 inhibits the processes. Thus, PsCRN63/115 manipulates plant PCD through interfering with catalases and perturbing H2O2 homeostasis. Furthermore, silencing of catalase genes enhances susceptibility to Phytophthora capsici, indicating that catalases are essential for plant resistance. Taken together, we suggest that P. sojae secretes these two effectors to regulate plant PCD and H2O2 homeostasis through direct interaction with catalases and, therefore, overcome host immune responses.
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two rxlr avirulence genes in Phytophthora sojae determine soybean rps1k mediated disease resistance
Molecular Plant-microbe Interactions, 2013Co-Authors: Tianqiao Song, Shiv D Kale, Yuanchao Wang, Daolong Dou, Li Liu, Danyu Shen, Felipe D Arredondo, Brett M. TylerAbstract:Resistance to Phytophthora sojae (Rps) genes have been widely used in soybean against root and stem rot diseases caused by this oomycete. Among 15 known soybean Rps genes, Rps1k has been the most widely used in the past four decades. Here, we show that the products of two distinct but closely linked RxLR effector genes are detected by Rps1k-containing plants, resulting in disease resistance. One of the genes is Avr1b-1, that confers avirulence in the presence of Rps1b. Three lines of evidence, including overexpression and gene silencing of Avr1b-1 in stable P. sojae transformants, as well as transient expression of this gene in soybean, indicated that Avr1b could trigger an Rps1k-mediated defense response. Some isolates of P. sojae that do not express Avr1b are nevertheless unable to infect Rps1k plants. In those isolates, we identified a second RxLR effector gene (designated Avr1k), located 5 kb away from Avr1b-1. Silencing or overexpression of Avr1k in P. sojae stable transformants resulted in the loss or gain, respectively, of the avirulence phenotype in the presence of Rps1k. Only isolates of P. sojae with mutant alleles of both Avr1b-1 and Avr1k could evade perception by the soybean plants carrying Rps1k.
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digital gene expression profiling of the Phytophthora sojae transcriptome
Molecular Plant-microbe Interactions, 2011Co-Authors: Xiaoli Wang, Suomeng Dong, Kai Tao, Tingting Dai, Daolong Dou, Mark Gijzen, Yuanchao WangAbstract:The transcriptome of the oomycete plant pathogen Phytophthora sojae was profiled at ten different developmental and infection stages based on a 3′-tag digital gene-expression protocol. More than 90 million clean sequence tags were generated and compared with the P. sojae genome and its 19,027 predicted genes. A total of 14,969 genes were detected, of which 10,044 were deemed reliable because they mapped to unambiguous tags. A comparison of the whole-library genes' expression patterns suggested four groups: i) mycelia and zoosporangia, ii) zoospores and cysts, iii) germinating cysts, and iv) five infection site libraries (IF1.5 to IF24h). The libraries from the different groups showed major transitional shifts in gene expression. From the ten libraries, 722 gene expression–pattern clusters were obtained and the top 16 clusters, containing more than half of the genes, comprised enriched genes with different functions including protein localization, triphosphate metabolism, signaling process, and noncoding R...
Brett M. Tyler - One of the best experts on this subject based on the ideXlab platform.
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efficient genome editing in the oomycete Phytophthora sojae using crispr cas9
Current protocols in microbiology, 2017Co-Authors: Brett M. Tyler, Yufeng Fang, Linkai Cui, Felipe ArredondoAbstract:Phytophthora is a filamentous fungus-like microorganism, but belongs to the oomycetes, in the kingdom Stramenopila. Phytophthora species are notorious as plant destroyers, causing multibillion-dollar damage to agriculture and natural ecosystems worldwide annually. For a long time, genome editing has been unattainable in oomycetes, because of their extremely low rate of homologous recombination. The recent implementation of the CRISPR/Cas (clustered regularly interspaced short palindromic repeats/CRISPR-associated) system in the soybean pathogen Phytophthora sojae, an experimental model for oomycetes, has opened up a powerful new research capability for the oomycete community. Here, we describe a detailed protocol for CRISPR/Cas9-mediated genome editing in P. sojae, including single guide RNA (sgRNA) design and construction, efficient gene replacement, and mutant-screening strategies. This protocol should be generally applicable for most culturable oomycetes. We also describe an optimized transformation method that is useful for other Phytophthora spp. including P. capsici and P. parasitica. © 2017 by John Wiley & Sons, Inc.
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distinctive nuclear localization signals in the oomycete Phytophthora sojae
Frontiers in Microbiology, 2017Co-Authors: Brett M. Tyler, Yufeng Fang, Hyo Sang Jang, Gregory W Watson, Dulani P WellappiliAbstract:To date, nuclear localization signals (NLSs) that target proteins to nuclei in oomycetes have not been defined, but have been assumed to be the same as in higher eukaryotes. Here, we use the soybean pathogen Phytophthora sojae as a model to investigate these sequences in oomycetes. By establishing a reliable in vivo NLS assay based on confocal microscopy, we found that many canonical monopartite and bipartite classical NLSs (cNLSs) mediated nuclear import poorly in P. sojae. We found that efficient localization of P. sojae nuclear proteins by cNLSs requires additional basic amino acids at distal sites or collaboration with other NLSs. We found that several representatives of another well-characterized NLS, proline-tyrosine NLS (PY-NLS) also functioned poorly in P. sojae. To characterize PY-NLSs in P. sojae, we experimentally defined the residues required by functional PY-NLSs in three P. sojae nuclear-localized proteins. These results showed that functional P. sojae PY-NLSs include an additional cluster of basic residues for efficient nuclear import. Finally, analysis of several highly conserved P. sojae nuclear proteins including ribosomal proteins and core histones revealed that these proteins exhibit a similar but stronger set of sequence requirements for nuclear targeting compared with their orthologs in mammals or yeast.
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two rxlr avirulence genes in Phytophthora sojae determine soybean rps1k mediated disease resistance
Molecular Plant-microbe Interactions, 2013Co-Authors: Tianqiao Song, Shiv D Kale, Yuanchao Wang, Daolong Dou, Li Liu, Danyu Shen, Felipe D Arredondo, Brett M. TylerAbstract:Resistance to Phytophthora sojae (Rps) genes have been widely used in soybean against root and stem rot diseases caused by this oomycete. Among 15 known soybean Rps genes, Rps1k has been the most widely used in the past four decades. Here, we show that the products of two distinct but closely linked RxLR effector genes are detected by Rps1k-containing plants, resulting in disease resistance. One of the genes is Avr1b-1, that confers avirulence in the presence of Rps1b. Three lines of evidence, including overexpression and gene silencing of Avr1b-1 in stable P. sojae transformants, as well as transient expression of this gene in soybean, indicated that Avr1b could trigger an Rps1k-mediated defense response. Some isolates of P. sojae that do not express Avr1b are nevertheless unable to infect Rps1k plants. In those isolates, we identified a second RxLR effector gene (designated Avr1k), located 5 kb away from Avr1b-1. Silencing or overexpression of Avr1k in P. sojae stable transformants resulted in the loss or gain, respectively, of the avirulence phenotype in the presence of Rps1k. Only isolates of P. sojae with mutant alleles of both Avr1b-1 and Avr1k could evade perception by the soybean plants carrying Rps1k.
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Structural basis for interactions of the Phytophthora sojae RxLR effector Avh5 with phosphatidylinositol 3-phosphate and for host cell entry.
Molecular plant-microbe interactions : MPMI, 2013Co-Authors: Furong Sun, Shiv D Kale, Hugo F. Azurmendi, Brett M. Tyler, Daniel G S CapellutoAbstract:Oomycetes such as Phytophthora sojae employ effector proteins that enter plant cells to facilitate infection. Entry of some effector proteins is mediated by RxLR motifs in the effectors and phosphoinositides (PIP) resident in the host plasma membrane such as phosphatidylinositol 3-phosphate (PtdIns(3)P). Recent reports differ regarding the regions on RxLR effectors involved in PIP recognition. We have structurally and functionally characterized the P. sojae effector, avirulence homolog-5 (Avh5). Using nuclear magnetic resonance (NMR) spectroscopy, we demonstrate that Avh5 is helical in nature, with a long N-terminal disordered region. NMR titrations of Avh5 with the PtdIns(3)P head group, inositol 1,3-bisphosphate, directly identified the ligand-binding residues. A C-terminal lysine-rich helical region (helix 2) was the principal lipid-binding site, with the N-terminal RxLR (RFLR) motif playing a more minor role. Mutations in the RFLR motif affected PtdIns(3)P binding, while mutations in the basic helix a...
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Phytophthora sojae root rot pathogen of soybean and model oomycete
Molecular Plant Pathology, 2007Co-Authors: Brett M. TylerAbstract:SUMMARY Phytophthora sojae is an oomycete pathogen of soybean, classified in the kingdom Stramenopiles. It causes ‘damping off’ of seedlings and root rot of older plants, with an annual cost worldwide of $1–2 billion. Owing to its economic importance, this species, along with P. infestans, has been developed as a model species for the study of oomycete plant pathogens. It is readily transformed with DNA enabling over-expression and silencing of selected genes, genetic maps have been constructed and large expressed sequence tag sequence libraries have been developed. A draft genome sequence has recently been completed. This review briefly summarizes current information about the pathogenicity, evolution, molecular biology and genomics of P. sojae. Taxonomy: Phytophthora sojae (Kaufman & Gerdman): superkingdom Eukaryota; kingdom Stramenopila; phylum Oomycota; class Peronosporomycetidae; order Pythiales; family Pythiaceae; genus Phytophthora. Host range: Soybean is the only economically important host. Several species of lupins have also been reported as hosts. Disease symptoms and signs: All parts of the soybean plant are susceptible to infection by P. sojae, from germinating seedlings to mature plants. In the field, P. sojae causes damping off of soybean seedlings and a root and stem rot of established plants. Leaves can be infected in the field as a result of rain splash or by deliberate inoculation in the laboratory. Damping off can affect germinating seeds or emerged seedlings and is most severe when the spring is very wet and warm (25–30 °C). Established plants can become infected when the soil is wet for extended periods, especially if the soil is poorly drained. Both the cortex and the vascular tissue are colonized by P. sojae, and the infection can spread rapidly along the vascular tissues in susceptible cultivars. Useful websites: http://pmgn.vbi.vt.edu, http://Phytophthora.vbi.vt.edu, http://www.jgi.doe.gov/Psojae, http://www.jgi.doe.gov/Pramorum, http://www.pfgd.org, http://pamgo.vbi.vt.edu, http://soy.vbi.vt.edu, https://www.vbi.vt.edu/article/articleview/78, http://plantpath.osu.edu/faculty/dorrance.php
Xiaobo Zheng - One of the best experts on this subject based on the ideXlab platform.
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g protein α subunit suppresses sporangium formation through a serine threonine protein kinase in Phytophthora sojae
PLOS Pathogens, 2020Co-Authors: Min Qiu, Mingrun Xuan, Xiaobo Zheng, Xin Zhang, Baiyu Zhang, Francine GoversAbstract:Eukaryotic heterotrimeric guanine nucleotide-binding proteins consist of α, β, and γ subunits, which act as molecular switches to regulate a number of fundamental cellular processes. In the oomycete pathogen Phytophthora sojae, the sole G protein α subunit (Gα; encoded by PsGPA1) has been found to be involved in zoospore mobility and virulence, but how it functions remains unclear. In this study, we show that the Gα subunit PsGPA1 directly interacts with PsYPK1, a serine/threonine protein kinase that consists of an N-terminal region with unknown function and a C-terminal region with a conserved catalytic kinase domain. We generated knockout and knockout-complemented strains of PsYPK1 and found that deletion of PsYPK1 resulted in a pronounced reduction in the production of sporangia and oospores, in mycelial growth on nutrient poor medium, and in virulence. PsYPK1 exhibits a cytoplasmic-nuclear localization pattern that is essential for sporangium formation and virulence of P. sojae. Interestingly, PsGPA1 overexpression was found to prevent nuclear localization of PsYPK1 by exclusively binding to the N-terminal region of PsYPK1, therefore accounting for its negative role in sporangium formation. Our data demonstrate that PsGPA1 negatively regulates sporangium formation by repressing the nuclear localization of its downstream kinase PsYPK1.
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the Phytophthora sojae avr1d gene encodes an rxlr deer effector with presence and absence polymorphisms among pathogen strains
Molecular Plant-microbe Interactions, 2013Co-Authors: Weixiao Yin, Suomeng Dong, Xiaobo Zheng, Yachun Lin, Luchong Zhai, Yuanchao WangAbstract:Soybean root and stem rot is caused by the oomycete pathogen Phytophthora sojae. The interaction between P. sojae and soybean fits the “gene-for-gene” hypothesis. Although more than 10 P. sojae avirulence (Avr) effectors have been genetically identified, nearly half of genetically defined avr genes have been cloned. In a previous bioinformatic and global transcriptional analysis, we identified a P. sojae RxLR effector, Avr1d, which was 125 amino acids in length. Mapping data demonstrated that Avr1d presence or absence in the genome was co-segregated with the Avr1d avirulence phenotype in F2 populations. Transient expression of the Avr1d gene using co-bombardment in soybean isogenic lines revealed that this gene triggered a hypersensitive response (HR) in the presence of Rps1d. Sequencing of Avr1d genes in different P. sojae strains revealed two Avr1d alleles. Although polymorphic, the two Avr1d alleles could trigger Rps1d-mediated HR. P. sojae strains carrying either of the alleles were avirulent on Rps1d...
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the rxlr effector avh241 from Phytophthora sojae requires plasma membrane localization to induce plant cell death
New Phytologist, 2012Co-Authors: Junli Tang, Qunqing Wang, Suomeng Dong, Kai Tao, Xiaobo Zheng, Xinyu Yang, Shuyi Duan, Yuanchao WangAbstract:• The Phytophthora sojae genome encodes hundreds of RxLR effectors predicted to manipulate various plant defense responses, but the molecular mechanisms involved are largely unknown. Here we have characterized in detail the P. sojae RxLR effector Avh241. • To determine the function and localization of Avh241, we transiently expressed it on different plants. Silencing of Avh241 in P. sojae, we determined its virulence during infection. Through the assay of promoting infection by Phytophthora capsici to Nicotiana benthamiana, we further confirmed this virulence role. • Avh241 induced cell death in several different plants and localized to the plant plasma membrane. An N-terminal motif within Avh241 was important for membrane localization and cell death-inducing activity. Two mitogen-activated protein kinases, NbMEK2 and NbWIPK, were required for the cell death triggered by Avh241 in N. benthamiana. Avh241 was important for the pathogen's full virulence on soybean. Avh241 could also promote infection by P. capsici and the membrane localization motif was not required to promote infection. • This work suggests that Avh241 interacts with the plant immune system via at least two different mechanisms, one recognized by plants dependent on subcellular localization and one promoting infection independent on membrane localization.
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development of a loop mediated isothermal amplification assay for detection of Phytophthora sojae
Fems Microbiology Letters, 2012Co-Authors: Tingting Dai, Suomeng Dong, Yuanchao Wang, Xiaobo ZhengAbstract:Phytophthora sojae is a devastating pathogen that causes soybean Phytophthora root rot. This study reports the development of a loop-mediated isothermal amplification (LAMP) assay targeting the A3aPro element for visual detection of P. sojae . The A3aPro -LAMP assay efficiently amplified the target element in < 80 min at 64 °C and was evaluated for specificity and sensitivity. The specificity was evaluated against P. sojae , Phytophthora spp., Pythium spp., and true fungi isolates. Magnesium pyrophosphate resulting from the LAMP of P. sojae could be detected by real-time measurement of turbidity. Phytophthora sojae DNA products were visualized as a ladder-like banding pattern on 2% gel electrophoresis. A positive colour (sky blue) was only observed in the presence of P. sojae with the addition of hydroxynaphthol blue prior to amplification, whereas none of other isolates showed a colour change. The detection limit of the A3aPro -specific LAMP assay for P. sojae was 10 pg µL−1 of genomic DNA per reaction. The assay also detected P. sojae from diseased soybean tissues and residues. These results suggest that the A3aPro -LAMP assay reported here can be used for the visual detection of P. sojae in plants and production fields.
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a myb transcription factor of Phytophthora sojae regulated by map kinase pssak1 is required for zoospore development
PLOS ONE, 2012Co-Authors: Meng Zhang, Suomeng Dong, Kai Tao, Xiaobo Zheng, Xiaoyun Liu, Liang Kong, Yuanchao WangAbstract:PsSAK1, a mitogen-activated protein (MAP) kinase from Phytophthora sojae, plays an important role in host infection and zoospore viability. However, the downstream mechanism of PsSAK1 remains unclear. In this study, the 3'-tag digital gene expression (DGE) profiling method was applied to sequence the global transcriptional sequence of PsSAK1-silenced mutants during the cysts stage and 1.5 h after inoculation onto susceptible soybean leaf tissues. Compared with the gene expression levels of the recipient P. sojae strain, several candidates of Myb family were differentially expressed (up or down) in response to the loss of PsSAK1, including of a R2R3-type Myb transcription factor, PsMYB1. qRT-PCR indicated that the transcriptional level of PsMYB1 decreased due to PsSAK1 silencing. The transcriptional level of PsMYB1 increased during sporulating hyphae, in germinated cysts, and early infection. Silencing of PsMYB1 results in three phenotypes: a) no cleavage of the cytoplasm into uninucleate zoospores or release of normal zoospores, b) direct germination of sporangia, and c) afunction in zoospore-mediated plant infection. Our data indicate that the PsMYB1 transcription factor functions downstream of MAP kinase PsSAK1 and is required for zoospore development of P. sojae.