Characterization of universally avirulent strains of Phytophthora sojae

1992 ◽  
Vol 70 (6) ◽  
pp. 1175-1185 ◽  
Author(s):  
Ravindra G. Bhat ◽  
Arthur F. Olah ◽  
August F. Schmitthenner
Keyword(s):  
Hypersensitive Response ◽  
Segregation Ratio ◽  
Phytophthora Sojae ◽  
Avirulent Strain ◽  
Plant Introductions ◽  
Seedling Rot ◽  
Race 1 ◽  
Glycine Max L ◽  
Microbe Interactions ◽  
Or Gene

During the process of selfing race 1 of Phytophthora sojae M. J. Kaufmann & J. W. Gerdemann, a pathogen of soybean (Glycine max (L.) Merr.), a 3:1 segregation ratio of race 1 to avirulence was obtained. Avirulent strains were identical in appearance to races 1, 3, and 4 but induced the hypersensitive response when inoculated on the universally susceptible soybean cultivar Williams. A representative avirulent strain did not cause disease on cultivars with known Rps (resistance to P. sojae) genes or gene combinations, or on 33 plant introductions that were susceptible to race 1. The avirulent strain rotted apples in a manner similar to races 1 and 4 and did not rot soybean pods similar to avirulent races. It induced the hypersensitive response in soybean cotyledons, which then rotted after being placed in flooded conditions. Seventy-eight typical avirulent single-oospore strains of P. sojae and Phytophthora and Pythium spp. induced the hypersensitive response and elicited as much glyceollin in 'Williams' and 'Williams 79' as races 1, 3, and 4 elicited in 'Williams'. Four Phytophthora spp., which caused some seedling rot of soybean, elicited levels of glyceollin as high as races 1 and 3 in 'Williams 79'. It is concluded that the avirulent strains obtained from race 1 are either pathogenic and have host-specificity for soybean or universally avirulent strains that have lost all race-specific virulence genes. Key words: Phytophthora sojae, soybean, pathogens, races, hypersensitivity, plant – microbe interactions.

scholarly journals Genetic Resistance of Lactuca spp. against Fusarium oxysporum f. sp. lactucae Race 1

HortScience ◽  
2021 ◽  
pp. 1-13
Author(s):  
Jesse J. Murray ◽  
Gulnoz Hisamutdinova ◽  
Germán V. Sandoya ◽  
Richard N. Raid ◽  
Stephanie Slinski
Keyword(s):  
Fusarium Oxysporum ◽  
Durable Resistance ◽  
Management Strategies ◽  
Genetic Resistance ◽  
Segregation Ratio ◽  
Sources Of Resistance ◽  
Breeding Lines ◽  
Plant Introductions ◽  
Soil Pathogen ◽  
Race 1

Fusarium wilt of lettuce is caused by the pathogen Fusarium oxysporum f. sp. lactucae (Fol) and is a growing threat to global lettuce production. Fol was first detected in Florida in 2017 and was subsequently confirmed as race 1. Management strategies for this long-persisting soil pathogen are limited, time-consuming and expensive, and they may lack efficacy. Identifying diverse sources of genetic resistance is imperative for breeding adapted cultivars with durable resistance. The objectives of this study were to identify sources of resistance against a race 1 isolate of Fol in Florida, delineate the relationship between foliar and taproot symptoms, and investigate the inheritance of resistance and partial resistance in two F2 populations. Thirteen experiments were conducted in greenhouse and field locations to characterize the diversity of genetic resistance in the genus Lactuca. Leaf cultivars Dark Lollo Rossa and Galactic; romaine breeding lines 43007, 60182, and C1145; and iceberg breeding line 47083 consistently exhibited low foliar and taproot disease symptoms. Resistance was not identified among the wildtype Lactuca or primitive plant introductions (PI) in this study based on taproot symptoms. An additional test was conducted to study the segregation pattern of Fol resistance between one resistant and one susceptible accession (R × S) and one partial resistant and one susceptible accession (PR × S). The F2 population from ‘60182 × PI 358001-1’ fit the expected segregation ratio for a single recessive locus model, whereas the ratio for ‘Dark Lollo Rossa × PI 358001-1’ did not fit either recessive or dominant single locus models. These sources of resistance are potential candidates for developing commercial cultivars with multiple resistance loci against Fol race 1, especially for the Florida lettuce production system.

Overexpression of a soybean 4-coumaric acid: coenzyme A ligase (GmPI4L) enhances resistance to Phytophthora sojae in soybean

2019 ◽  
Vol 46 (4) ◽  
pp. 304 ◽  
Author(s):  
Xi Chen ◽  
Xin Fang ◽  
Youyi Zhang ◽  
Xin Wang ◽  
Chuanzhong Zhang ◽  
...  
Keyword(s):  
Phytophthora Sojae ◽  
Plant Responses ◽  
Coumaric Acid ◽  
Coa Ligase ◽  
Coenzyme A Ligase ◽  
Subtractive Hybridisation ◽  
Race 1 ◽  
Glycine Max L ◽  
Soybean Plants ◽  
Suppressive Subtractive Hybridisation

Phytophthora root and stem rot of soybean (Glycine max (L.) Merr.) caused by Phytophthora sojae is a destructive disease worldwide. The enzyme 4-coumarate: CoA ligase (4CL) has been extensively studied with regard to plant responses to pathogens. However, the molecular mechanism of the response of soybean 4CL to P. sojae remains unclear. In a previous study, a highly upregulated 4CL homologue was characterised through suppressive subtractive hybridisation library and cDNA microarrays, in the resistant soybean cultivar ‘Suinong 10’ after infection with P. sojae race 1. Here, we isolated the full-length EST, and designated as GmPI4L (P. sojae-inducible 4CL gene) in this study, which is a novel member of the soybean 4CL gene family. GmPI4L has 34–43% over all amino acid sequence identity with other plant 4CLs. Overexpression of GmPI4L enhances resistance to P. sojae in transgenic soybean plants. The GmPI4L is located in the cell membrane when transiently expressed in Arabidopsis protoplasts. Further analyses showed that the contents of daidzein, genistein, and the relative content of glyceollins are significantly increased in overexpression GmPI4L soybeans. Taken together, these results suggested that GmPI4L plays an important role in response to P. sojae infection, possibly by enhancing the content of glyceollins, daidzein, and genistein in soybean.

scholarly journals Specific hypersensitive response-associated recognition of new apoplastic effectors fromCladosporium fulvumin wild tomato

2017 ◽  
Author(s):  
Carl H. Mesarich ◽  
Bilal Ökmen ◽  
Hanna Rovenich ◽  
Scott A. Griffiths ◽  
Changchun Wang ◽  
...  
Keyword(s):  
Hypersensitive Response ◽  
Expression System ◽  
Potato Virus X ◽  
Cladosporium Fulvum ◽  
In Planta ◽  
Antimicrobial Proteins ◽  
Wild Tomato ◽  
Microbe Interactions ◽  
Leaf Apoplast ◽  
Tomato Leaf Mould

ABSTRACTTomato leaf mould disease is caused by the biotrophic fungusCladosporium fulvum. During infection,C. fulvumproduces extracellular small secreted protein (SSP) effectors that function to promote colonization of the leaf apoplast. Resistance to the disease is governed byCfimmune receptor genes that encode receptor-like proteins (RLPs). These RLPs recognize specific SSP effectors to initiate a hypersensitive response (HR) that renders the pathogen avirulent.C. fulvumstrains capable of overcoming one or more of all clonedCfgenes have now emerged. To combat these strains, newCfgenes are required. An effectoromics approach was employed to identify wild tomato accessions carrying newCfgenes. Proteomics and transcriptome sequencing were first used to identify 70 apoplasticin planta-inducedC. fulvumSSPs. Based on sequence homology, 61 of these SSPs were novel or lacked known functional domains. Seven, however, had predicted structural homology to antimicrobial proteins, suggesting a possible role in mediating antagonistic microbe−microbe interactionsin planta. Wild tomato accessions were then screened for HR-associated recognition of 41 SSPs using thePotato virus X-based transient expression system. Nine SSPs were recognized by one or more accessions, suggesting that these plants carry newCfgenes available for incorporation into cultivated tomato.

Common Phytophthora sojae pathotypes occurring in South Dakota

2021 ◽  
Author(s):  
Rawnaq Chowdhury ◽  
Connie Tande ◽  
Emmanuel Z Byamukama
Keyword(s):  
Glycine Max ◽  
South Dakota ◽  
Resistance Genes ◽  
Phytophthora Sojae ◽  
Stem Rot ◽  
Inoculation Technique ◽  
Glycine Max L ◽  
Rps Gene ◽  
Important Disease

Phytophthora root and stem rot, caused by Phytophthora sojae, is an important disease of soybean (Glycine max L.) in South Dakota. Because P. sojae populations are highly diverse and resistance genes deployed in commercial soybean varieties often fail to manage the disease, this study was initiated to determine P. sojae pathotype distribution in South Dakota. A total of 216 P. sojae isolates were baited from soil collected from 422 soybean fields in South Dakota in 2013-2015 and 2017. The pathotype of each isolate was determined by inoculating 10 seedlings of 13 standard soybean P. sojae differential lines using the hypocotyl inoculation technique. Of the 216 pathotyped isolates, 48 unique pathotypes were identified. The virulence complexity of isolates ranged from virulence on one Rps gene (Rps7) to virulence on 13 Rps genes and mean complexity was 5.2. Harosoy (Rps7), Harlon (Rps1a), Williams 79 (Rps 1c), William 82 (Rps1k), Harosoy 13XX (Rps1b), were susceptible to 98, 80, 78, 73, 72% of the isolates, respectively. These results highlight the highly diverse P. sojae pathotypes in South Dakota and the likely Rps genes to fail in commercial soybean varieties

scholarly journals Isolate-Dependent Inheritance of Resistance Against Pseudoperonospora cubensis in Cucumber

Agronomy ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1086 ◽  
Author(s):  
Tomer Chen ◽  
Daniel Katz ◽  
Yariv Ben Naim ◽  
Rivka Hammer ◽  
Bat Hen Ben Daniel ◽  
...  
Keyword(s):  
Segregation Ratio ◽  
Lesion Size ◽  
Pseudoperonospora Cubensis ◽  
Plant Introductions ◽  
Growing Seasons ◽  
Multiple Phenotypes ◽  
Progress Curve ◽  
Growth Chambers ◽  
Wild Accessions ◽  
Moderately Resistant

Six wild accessions of Cucumis sativum were evaluated for resistance against each of the 23 isolates of the downy mildew oomycete Pseudoperonospora cubensis. The isolates originated from Israel, Europe, USA, and Asia. C. sativum PI 197088 (India) and PI 330628 (Pakistan) exhibited the highest level of resistance against multiple isolates of P. cubensis. Resistance was manifested as reduced lesion number, lesion size, sporangiophores and sporangia per lesion and enhanced encasement of haustoria with callose and intensive accumulation of lignin in lesions of both Plant Introductions (PIs) compared to the susceptible C. sativum SMR-18. In the field, much smaller AUDPC (Area Under Disease Progress Curve) values were recorded in PI 197088 or PI 330628 as compared to SMR-18. Each PI was crossed with SMR-18 and offspring progeny plants were exposed to inoculation with each of several isolates of P. cubensis in growth chambers and the field during six growing seasons. F1 plants showed partial resistance. F2 plants showed multiple phenotypes ranging from highly susceptible (S) to highly resistant (R, no symptoms) including moderately resistant (MR) phenotypes. The segregation ratio between phenotypes in growth chambers ranged from 3:1 to 1:15, depending on the isolate used for inoculation, suggesting that the number of genes, dominant, partially dominant, or recessive are responsible for resistance. In the field, the segregation ratio of 1:15, 1:14:1, or 1:9:6 was observed. F2 progeny plants of the cross between the two resistant PI’s were resistant, except for a few plants that were partially susceptible, suggesting that some of the resistance genes in PI 197088 and PI 330328 are not allelic.

scholarly journals GmWRKY40, a member of the WRKY transcription factor genes identified from Glycine max L., enhanced the resistance to Phytophthora sojae

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Xiaoxia Cui ◽  
Qiang Yan ◽  
Shuping Gan ◽  
Dong Xue ◽  
Haitang Wang ◽  
...  
Keyword(s):  
Wrky Transcription Factor ◽  
Phytophthora Sojae ◽  
Research Progress ◽  
Interaction Patterns ◽  
Transgenic Roots ◽  
Physiological Processes ◽  
Transcription Factor Genes ◽  
Glycine Max L ◽  
Soybean Plants ◽  
Ja Signaling

Abstract Background The WRKY proteins are a superfamily of transcription factors and members play essential roles in the modulation of diverse physiological processes, such as growth, development, senescence and response to biotic and abiotic stresses. However, the biological roles of the majority of the WRKY family members remains poorly understood in soybean relative to the research progress in model plants. Results In this study, we identified and characterized GmWRKY40, which is a group IIc WRKY gene. Transient expression analysis revealed that the GmWRKY40 protein is located in the nucleus of plant cells. Expression of GmWRKY40 was strongly induced in soybean following infection with Phytophthora sojae, or treatment with methyl jasmonate, ethylene, salicylic acid, and abscisic acid. Furthermore, soybean hairy roots silencing GmWRKY40 enhanced susceptibility to P. sojae infection compared with empty vector transgenic roots. Moreover, suppression of GmWRKY40 decreased the accumulation of reactive oxygen species (ROS) and modified the expression of several oxidation-related genes. Yeast two-hybrid experiment combined with RNA-seq analysis showed that GmWRKY40 interacted with 8 JAZ proteins with or without the WRKY domain or zinc-finger domain of GmWRKY40, suggesting there were different interaction patterns among these interacted proteins. Conclusions Collectively, these results suggests that GmWRKY40 functions as a positive regulator in soybean plants response to P. sojae through modulating hydrogen peroxide accumulation and JA signaling pathway.

Association mapping for partial resistance to Phytophthora sojae in soybean (Glycine max (L.) Merr.)

2014 ◽  
Vol 93 (2) ◽  
pp. 355-363 ◽  
Author(s):  
JUTAO SUN ◽  
NA GUO ◽  
JUN LEI ◽  
LIHONG LI ◽  
GUANJUN HU ◽  
...  
Keyword(s):  
Glycine Max ◽  
Association Mapping ◽  
Partial Resistance ◽  
Phytophthora Sojae ◽  
Glycine Max L

DNA CONTENT, RIBOSOMAL-RNA GENE NUMBER, AND PROTEIN CONTENT IN SOYBEANS

1978 ◽  
Vol 20 (4) ◽  
pp. 531-538 ◽  
Author(s):  
Earle B. Doerschug ◽  
Jerome P. Miksche ◽  
Reid G. Palmer
Keyword(s):  
Glycine Max ◽  
Protein Content ◽  
Ribosomal Rna ◽  
Seed Protein ◽  
Seed Protein Content ◽  
Plant Introductions ◽  
Genetic Manipulations ◽  
Glycine Max L ◽  
Rna Genes ◽  
Percentage Protein

Six cultivars and five plant introductions of Glycine max L. Merr. varied in picograms of DNA per cell from 1.84 to 2.61, and in number of ribosomal-RNA genes per 2 C nucleus from 960 to 2431 (Laboratory 1, Ames) and from 768 to 2095 (Laboratory 2, Rhinelander). The parameters did not correlate with seed protein content, which varied from 32.8% to 52.6%. With these materials, use of the rRNA locus size as a breeding tool for increasing percentage protein content by use of cytogenetic and genetic manipulations is not warranted.

Conservation of leghemoglobin heterogeneity and structures in cultivated and wild soybean

1985 ◽  
Vol 63 (11) ◽  
pp. 1951-1956 ◽  
Author(s):  
W. H. Fuchsman ◽  
R. G. Palmer
Keyword(s):  
Glycine Max ◽  
Isoelectric Focusing ◽  
Bradyrhizobium Japonicum ◽  
Glycine Soja ◽  
Wild Soybean ◽  
Rhizobium Japonicum ◽  
Plant Introductions ◽  
Glycine Max L ◽  
Cultivated Soybean ◽  
Selection Of

The leghemoglobins from a genetically diverse selection of 69 cultivated soybean (Glycine max (L.) Merr.) cultivars and plant introductions and 18 wild soybean (Glycine soja Sieb. & Zucc.) plant introductions all consist of the same set of major leghemoglobins (a, c1, c2, c3), as determined by analytical isoelectric focusing. The conservation of both leghemoglobin heterogeneity and also all four major leghemoglobin structures provides strong circumstantial evidence that leghemoglobin heterogeneity is functional. Glycine max and G. soja produced the same leghemoglobins in the presence of Bradyrhizobium japonicum (Kirchner) Jordan and in the presence of fast-growing Rhizobium japonicum.

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