scholarly journals Esophageal Gland RNA-seq Resource of a Virulent and Avirulent Population of the Soybean Cyst Nematode, Heterodera glycines.

2021 ◽  
Author(s):  
Tom Maier ◽  
Rick E. Masonbrink ◽  
Paramasivan Vijayapalani ◽  
Michael Gardner ◽  
Amanda D. Howland ◽  
...  
Keyword(s):  
Soybean Cyst Nematode ◽  
Gland Cell ◽  
Heterodera Glycines ◽  
The United States ◽  
Cyst Nematode ◽  
Effector Proteins ◽  
Genomic Research ◽  
Natural Resistance ◽  
Rna Seq ◽  
Management Options

The soybean cyst nematode, Heterodera glycines, is the most economically devastating pathogen of soybean in the United States and threatens to become even more damaging through the selection of virulent nematode populations in the field that can overcome natural resistance mechanisms in soybean cultivars. This pathogen, therefore, demands intense transcriptomic/genomic research inquiries into the biology of its parasitic mechanisms. H. glycines delivers effector proteins that are produced in specialized gland cells into the soybean root to enable infection. The study of effector proteins, thus, is particularly promising when exploring novel management options against this pathogen. Here we announce the availability of a gland cell-specific RNA-seq resource. These data represent an expression snapshot of gland cell activity during early soybean infection of a virulent and an avirulent H. glycines population, which provides a unique and highly valuable resource for scientists examining effector biology and nematode virulence.

Characterization of Virulence Phenotypes of Soybean Cyst Nematode (Heterodera glycines) Populations in North Dakota

2021 ◽  
Author(s):  
Intiaz Amin Chowdhury ◽  
Guiping Yan ◽  
Addison Plaisance ◽  
sam markell
Keyword(s):  
North Dakota ◽  
Soybean Cyst Nematode ◽  
Heterodera Glycines ◽  
The United States ◽  
Cyst Nematode ◽  
Sources Of Resistance ◽  
Resistance Sources ◽  
First Time ◽  
Primary Strategy

Soybean cyst nematode (SCN; Heterodera glycines) continues to be the greatest threat to soybean production in the United States. Since host resistance is the primary strategy used to control SCN, knowledge of SCN virulence phenotypes (HG types) is necessary for choosing sources of resistance for SCN management. To characterize SCN virulence phenotypes in North Dakota (ND), a total of 419 soybean fields across 22 counties were sampled during 2015, 2016, and 2017. SCN was detected in 42% of the fields sampled and population densities in these samples ranged from 30 to 92,800 eggs and juveniles per 100 cm3 of soil. The SCN populations from some of the infested fields were virulence phenotyped with seven soybean indicator lines and a susceptible check (Barnes) using the HG type tests. Overall, 73 SCN field populations were successfully virulence phenotyped. The HG types detected in ND were HG type 0 (frequency rate: 36%), 7 (27%), 2.5.7 (19%), 5.7 (11%), 1.2.5.7 (4%), and 2.7 (2%). However, prior to this study only HG type 0 was detected in ND. The designation of each of the HG types detected was then validated in this study by repeating the HG type tests for thirty-three arbitrarily selected samples. This research for the first time reports several new HG types detected in ND and confirms that the virulence of SCN populations is shifting and overcoming resistance, highlighting the necessity of utilization of different resistance sources, rotation of resistance sources, and identification of novel resistance sources for SCN management in ND.

scholarly journals Known Distribution of the Soybean Cyst Nematode, Heterodera glycines, in the United States and Canada, 1954 to 2017

2017 ◽  
Vol 18 (3) ◽  
pp. 167-168 ◽  
Author(s):  
Gregory L. Tylka ◽  
Christopher C. Marett
Keyword(s):  
United States ◽  
New York ◽  
North America ◽  
North Dakota ◽  
Soybean Cyst Nematode ◽  
Heterodera Glycines ◽  
The United States ◽  
Cyst Nematode ◽  
The State ◽  
Introduced Pest

The soybean cyst nematode (SCN) is a major yield-reducing pathogen of soybeans in North America. The nematode is an introduced pest and, therefore, knowledge of the distribution of SCN can be helpful in identifying areas where scouting and management efforts should be focused. Such information is especially important because yield-reducing infestations of SCN can occur without obvious above-ground symptoms appearing. In late 2016, nematologists, plant pathologists, and state plant regulatory officials from the soybean-producing states in the United States and provinces in Canada were queried to obtain the latest information on where the nematode had been found. An updated map of the known distribution of SCN in North America was also created. There were 17 states in which SCN was newly found since 2014, when the map was last updated, including the first discovery of SCN in the state of New York. North Dakota was the state with the greatest number of counties, seven, in which SCN had been newly discovered since 2014. This updated information illustrates that the nematode continues to spread throughout the soybean-growing areas of the continent and emphasizes that continued efforts to scout for and manage SCN are warranted.

Screening of Early Maturing Soybean Accessions for Resistance against HG Type 2.5.7 of Soybean Cyst Nematode, Heterodera glycines

2021 ◽  
Author(s):  
Krishna Acharya ◽  
Guiping Yan
Keyword(s):  
Soybean Cyst Nematode ◽  
Heterodera Glycines ◽  
Nematode Resistance ◽  
The United States ◽  
Cyst Nematode ◽  
Primary Methods ◽  
Resistance Response ◽  
Early Maturity ◽  
Resistant Cultivars ◽  
Moderately Resistant

Soybean cyst nematode (SCN; Heterodera glycines) is one of the devastating soybean pests worldwide, including the United States. Resistant cultivars combined with crop rotation are the primary methods for managing this nematode. SCN is known to have genetically diverse populations and can develop new virulent forms over time due to the continuous planting of cultivars derived from same source of resistance. Thus, identifying novel SCN resistant sources is of paramount importance for soybean breeding for nematode resistance. In this study, we screened 149 early maturity soybean [Glycine max (L.)] accessions for resistance to SCN HG type 2.5.7, which is one of the prevalent virulent SCN populations in North Dakota. SCN white females were extracted from individual plants of each accession after 35 days of growth in greenhouse conditions. The females were counted to determine a female index [FI = (average number of females on a tested accession/average number of females in Barnes, a susceptible soybean check) x 100]. The resistance response of each soybean accession was categorized as resistant, moderately resistant, moderately susceptible, and susceptible. Out of the soybean 149 accessions tested, only 13 were resistant in both runs of the experiments. The majority of screened soybean accessions were susceptible or moderately susceptible to the SCN HG type 2.5.7. The resistant soybean accessions identified in this study have the potential to be used in breeding SCN-resistant cultivars after further elucidation of the resistance genes or loci.

scholarly journals Eighteen New Candidate Effectors of the Phytonematode Heterodera glycines Produced Specifically in the Secretory Esophageal Gland Cells During Parasitism

2015 ◽  
Vol 105 (10) ◽  
pp. 1362-1372 ◽  
Author(s):  
Jason B. Noon ◽  
Tarek Hewezi ◽  
Thomas R. Maier ◽  
Carl Simmons ◽  
Jun-Zhi Wei ◽  
...  
Keyword(s):  
Soybean Cyst Nematode ◽  
Gland Cell ◽  
Heterodera Glycines ◽  
Effector Proteins ◽  
Feeding Site ◽  
Gland Cells ◽  
Esophageal Gland ◽  
Mining Projects ◽  
In Situ Hybridizations

Heterodera glycines, the soybean cyst nematode, is the number one pathogen of soybean (Glycine max). This nematode infects soybean roots and forms an elaborate feeding site in the vascular cylinder. H. glycines produces an arsenal of effector proteins in the secretory esophageal gland cells. More than 60 H. glycines candidate effectors were identified in previous gland-cell-mining projects. However, it is likely that additional candidate effectors remained unidentified. With the goal of identifying remaining H. glycines candidate effectors, we constructed and sequenced a large gland cell cDNA library resulting in 11,814 expressed sequence tags. After bioinformatic filtering for candidate effectors using a number of criteria, in situ hybridizations were performed in H. glycines whole-mount specimens to identify candidate effectors whose mRNA exclusively accumulated in the esophageal gland cells, which is a hallmark of many nematode effectors. This approach resulted in the identification of 18 new H. glycines esophageal gland-cell-specific candidate effectors. Of these candidate effectors, 11 sequences were pioneers without similarities to known proteins while 7 sequences had similarities to functionally annotated proteins in databases. These putative homologies provided the bases for the development of hypotheses about potential functions in the parasitism process.

scholarly journals Known Distribution of the Soybean Cyst Nematode, Heterodera glycines, in the United States and Canada in 2020

2021 ◽  
Author(s):  
Gregory L. Tylka ◽  
Christopher C. Marett
Keyword(s):  
United States ◽  
Glycine Max ◽  
Health Professionals ◽  
Soybean Cyst Nematode ◽  
Heterodera Glycines ◽  
The United States ◽  
Cyst Nematode ◽  
Soil Sampling ◽  
Rural Municipalities ◽  
Canadian Provinces

In the United States and Canada, the most damaging pathogen of soybean, Glycine max, is the soybean cyst nematode (SCN), Heterodera glycines. Plant health professionals working for universities and state and provincial departments of agriculture in the United States and Canada are queried periodically about counties and rural municipalities that are newly known to be infested with SCN in their states and provinces. Such a census was conducted in 2020, and the results were compared with results of the most recent survey, published in 2017. Between 2017 and 2020, 55 new SCN-infested counties were reported from 11 U.S. states. Also, 24 new SCN-infested counties and rural municipalities were identified in the Canadian provinces of Manitoba, Ontario, and Quebec. A map of the known distribution of SCN in these two countries was updated. The results reveal steady expansion of the distribution of SCN throughout the United States and Canada, and the pest almost certainly will continue to spread among and within soybean-producing areas of these countries in the future. Therefore, continued scouting and soil sampling for detection of new SCN infestations are warranted as the first step toward successfully managing the pathogen.

scholarly journals Soybean Resistance to the Soybean Cyst Nematode Heterodera glycines: An Update

2016 ◽  
Vol 106 (12) ◽  
pp. 1444-1450 ◽  
Author(s):  
Melissa G. Mitchum
Keyword(s):  
Soybean Cyst Nematode ◽  
Heterodera Glycines ◽  
Cyst Nematode ◽  
Natural Resistance ◽  
Biochemical Basis ◽  
The World ◽  
Scn Resistance ◽  
Soybean Resistance ◽  
Nematode Virulence

The soybean cyst nematode (SCN), Heterodera glycines, remains a serious threat to soybean production throughout the world. A lack of genetic diversity in resistant soybean cultivars has led to a widespread shift toward virulence in SCN populations, leaving farmers with few proven options other than nonhost rotation to manage this nematode. Recent advances in our understanding of the genes controlling resistance to the nematode have led to improved molecular markers, which are, in turn, increasing the efficiency and precision of the breeding pipeline. A better understanding of the molecular and biochemical basis of SCN resistance and nematode virulence will provide information useful for the development of a long-term strategic plan for diversification and the deployment of cultivars that protect current sources of natural resistance while identifying new targets for engineering novel resistance.

Distribution of the Soybean Cyst Nematode, Heterodera glycines, in the United States and Canada: 1954 to 2014

2014 ◽  
Vol 15 (2) ◽  
pp. 85-87 ◽  
Author(s):  
Gregory L. Tylka ◽  
Christopher C. Marett
Keyword(s):  
United States ◽  
North America ◽  
Soybean Cyst Nematode ◽  
Yield Loss ◽  
Heterodera Glycines ◽  
The United States ◽  
Cyst Nematode ◽  
The Usa ◽  
Initial Discovery

The soybean cyst nematode (Heterodera glycines) is considered the most damaging pathogen of soybean in the USA and Canada, and causes considerable yield loss in many other soybean-producing countries. It is believed to have been introduced into North America from Asia. The map of the known distribution of H. glycines in the USA and Canada has been updated for 2014. Maps of its known distribution in past years illustrate the spread of the pathogen since its initial discovery in the United States in 1954. Accepted for publication 20 April 2014. Published 27 May 2014.

scholarly journals Signal Peptide-Selection of cDNA Cloned Directly from the Esophageal Gland Cells of the Soybean Cyst Nematode Heterodera glycines

2001 ◽  
Vol 14 (4) ◽  
pp. 536-544 ◽  
Author(s):  
Xiaohong Wang ◽  
Rex Allen ◽  
Xiongfei Ding ◽  
Melissa Goellner ◽  
Tom Maier ◽  
...  
Keyword(s):  
Signal Peptide ◽  
Soybean Cyst Nematode ◽  
Gland Cell ◽  
Heterodera Glycines ◽  
Cyst Nematode ◽  
Extracellular Proteins ◽  
Cdna Clones ◽  
Gland Cells ◽  
Esophageal Gland ◽  
Selection Of

Secretions from the esophageal gland cells of plantparasitic nematodes play critical roles in the nematodeparasitic cycle. A novel method to isolate cDNA encoding putative nematode secretory proteins was developed that utilizes mRNA for reverse transcription-polymerase chain reaction derived from microaspiration of the esophageal gland cell contents of parasitic stages of the soybean cyst nematode Heterodera glycines. The resulting H. glycines gland cell cDNA was cloned into the pRK18 vector, and plasmid DNA was transformed into a mutated yeast host for specific selection of cDNA inserts that encode proteins with functional signal peptides. Of the 223 cDNA clones recovered from selection in yeast, 97% of the clones encoded a predicted signal peptide. Fourteen unique cDNA clones hybridized to genomic DNA of H. glycines on Southern blots and, among them, nine cDNA clones encoded putative extracellular proteins, as predicted by PSORT II computer analysis. Four cDNA clones hybridized to transcripts within the dorsal esophageal gland cell of parasitic stages of H. glycines, and in situ hybridization within H. glycines was not detected for eight cDNA clones. The protocol provides a direct means to isolate potential plant-parasitic nematode esophageal gland secretory protein genes.

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