scholarly journals A Bacillus thuringiensis Cry protein controls soybean cyst nematode in transgenic soybean plants

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Theodore W. Kahn ◽  
Nicholas B. Duck ◽  
Michael T. McCarville ◽  
Laura Cooper Schouten ◽  
Kathryn Schweri ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Soybean Cyst Nematode ◽  
Field Trials ◽  
Cyst Nematode ◽  
Parasitic Nematodes ◽  
Transgenic Soybean ◽  
Cry Protein ◽  
C Elegans ◽  
Slow Decline ◽  
Soybean Plants

AbstractPlant-parasitic nematodes (PPNs) are economically important pests of agricultural crops, and soybean cyst nematode (SCN) in particular is responsible for a large amount of damage to soybean. The need for new solutions for controlling SCN is becoming increasingly urgent, due to the slow decline in effectiveness of the widely used native soybean resistance derived from genetic line PI 88788. Thus, developing transgenic traits for controlling SCN is of great interest. Here, we report a Bacillus thuringiensis delta-endotoxin, Cry14Ab, that controls SCN in transgenic soybean. Experiments in C. elegans suggest the mechanism by which the protein controls nematodes involves damaging the intestine, similar to the mechanism of Cry proteins used to control insects. Plants expressing Cry14Ab show a significant reduction in cyst numbers compared to control plants 30 days after infestation. Field trials also show a reduction in SCN egg counts compared with control plants, demonstrating that this protein has excellent potential to control PPNs in soybean.

scholarly journals Soybean plants expressing the Bacillus thuringiensis cry8-like gene show resistance to Holotrichia parallela

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Di Qin ◽  
Xiao-Yi Liu ◽  
Cristina Miceli ◽  
Qi Zhang ◽  
Pi-wu Wang
Keyword(s):  
Bacillus Thuringiensis ◽  
Transgenic Plants ◽  
Survival Rates ◽  
Pcr Analysis ◽  
Transgenic Soybean ◽  
Cry Protein ◽  
Transgenic Expression ◽  
Holotrichia Parallela ◽  
Soybean Plants ◽  
Soybean Leaves

Abstract Background Cry8-like from Bacillus thuringiensis (Bt) encodes an insecticidal crystal (Cry) protein. Holotrichia parallela (Coleoptera: Scarabaeoidae), commonly known as the dark black chafer, is a troublesome pest of soybean (Glycine max). To test whether cry8-like can confer resistance against H. parallela to soybean, we introduced cry8-like from the Bt strain HBF-18 into soybean cultivar Jinong 28. Results Quantitative reverse transcription-PCR analysis demonstrated that cry8-like was expressed most highly in soybean leaves. In addition, Southern blot assays revealed that one copy of the integrated fragment was present in the transformed plants. Eight independent cry8-like transgenic lines were subsequently fed on by H. parallela. Under H. parallela feeding stress, the survival rates of the non-transgenic plants were 92% lower than those of the transgenic plants. The mortality rate of H. parallela increased when the larvae fed on the roots of T1 transgenic soybean plants. Moreover, the surviving larvae were deformed, and their growth was inhibited. Conclusions Collectively, our data suggest that transgenic soybean plants expressing the cry8-like gene are more resistant to H. parallela than non-transgenic plants and that transgenic expression of the cry8-like gene may represent a promising strategy for engineering pest tolerance. The events generated in this study could thus be utilized in soybean breeding programs.

scholarly journals The genome of the soybean cyst nematode (Heterodera glycines) reveals complex patterns of duplications involved in the evolution of parasitism genes

2018 ◽  
Author(s):  
Rick Masonbrink ◽  
Tom R. Maier ◽  
Usha Muppiral ◽  
Arun S. Seetharam ◽  
Etienne Lord ◽  
...  
Keyword(s):  
Soybean Cyst Nematode ◽  
Heterodera Glycines ◽  
Control Strategies ◽  
Cyst Nematode ◽  
Effective Control ◽  
Evolutionary Mechanisms ◽  
Long Read ◽  
Soybean Plants ◽  
Parasitism Genes ◽  
Nematode Genomes

AbstractHeterodera glycines, commonly referred to as the soybean cyst nematode (SCN), is an obligatory and sedentary plant parasite that causes over a billion-dollar yield loss to soybean production annually. Although there are genetic determinants that render soybean plants resistant to certain nematode genotypes, resistant soybean cultivars are increasingly ineffective because their multi-year usage has selected for virulentH. glycinespopulations. The parasitic success ofH. glycinesrelies on the comprehensive re-engineering of an infection site into a syncytium, as well as the long-term suppression of host defense to ensure syncytial viability. At the forefront of these complex molecular interactions are effectors, the proteins secreted byH. glycinesinto host root tissues. The mechanisms of effector acquisition, diversification, and selection need to be understood before effective control strategies can be developed, but the lack of an annotated genome has been a major roadblock. Here, we use PacBio long-read technology to assemble aH. glycinesgenome of 738 contigs into 123Mb with annotations for 29,769 genes. The genome contains significant numbers of repeats (34%), tandem duplicates (18.7Mb), and horizontal gene transfer events (151 genes). Using previously published effector sequences, the newly generatedH. glycinesgenome, and comparisons to other nematode genomes, we investigate the evolutionary mechanisms responsible for the emergence and diversification of effector genes.

scholarly journals Marker-assisted selection strategies for developing resistant soybean plants to cyst nematode

2014 ◽  
Vol 14 (3) ◽  
pp. 180-186 ◽  
Author(s):  
Fernanda Abreu Santana ◽  
Martha Freire da Silva ◽  
Julierme Kellen Freitas Guimarães ◽  
Marcia Flores da Silva Ferreira ◽  
Waldir Dias Pereira ◽  
...  
Keyword(s):  
Marker Assisted Selection ◽  
Soybean Cyst Nematode ◽  
Cyst Nematode ◽  
Selection Strategies ◽  
Resistant Lines ◽  
Resistance Trait ◽  
Scn Resistance ◽  
Soybean Plants ◽  
Moderate Resistance ◽  
Selection Of

Resistant lines can be identified by marker-assisted selection(MAS), based on alleles of genetic markers linked to the resistance trait. This reduces the number of phenotypically evaluated lines, one of the limitations in the development of cultivars with resistance to soybean cyst nematode (SCN).This study evaluated the efficiency of microsatellites near quantitative traitloci (QTL) for SCN resistance, in the linkage groups (LG) G and A2 of soybean, for the selection of resistant genotypes in populations originated from crosses between the cultivars Vmax and CD201. The QTL of LG A2 was not detected in 'Vmax' (derived from PI 88788). In MAS, the microsatellites of LG G were efficient in selecting F6:7 families with resistance and moderate resistance to SCN race 3. The selection efficiency of the microsatellites Sat_168, Satt309 and Sat_141 was greater than 93%.

Yield components of soybean plants infected with soybean cyst nematode and sprayed with foliar applications of boron and magnesium1

2000 ◽  
Vol 23 (6) ◽  
pp. 827-834 ◽  
Author(s):  
Gordon Smith ◽  
William Wiebold ◽  
T.L. Niblack ◽  
Peter Scharf ◽  
Dale Blevins
Keyword(s):  
Yield Components ◽  
Soybean Cyst Nematode ◽  
Cyst Nematode ◽  
Soybean Plants

scholarly journals Bacillus thuringiensis (Bt) Toxin Susceptibility and Isolation of Resistance Mutants in the Nematode Caenorhabditis elegans

Genetics ◽  
2000 ◽  
Vol 155 (4) ◽  
pp. 1693-1699
Author(s):  
Lisa D Marroquin ◽  
Dino Elyassnia ◽  
Joel S Griffitts ◽  
Jerald S Feitelson ◽  
Raffi V Aroian
Keyword(s):  
Caenorhabditis Elegans ◽  
Bacillus Thuringiensis ◽  
Molecular Genetic ◽  
Molecular Genetic Analysis ◽  
Parasitic Nematodes ◽  
Bt Toxin ◽  
C Elegans ◽  
Bt Toxins ◽  
Protein Toxins ◽  
Toxicity Pathway

Abstract The protein toxins produced by Bacillus thuringiensis (Bt) are the most widely used natural insecticides in agriculture. Despite successful and extensive use of these toxins in transgenic crops, little is known about toxicity and resistance pathways in target insects since these organisms are not ideal for molecular genetic studies. To address this limitation and to investigate the potential use of these toxins to control parasitic nematodes, we are studying Bt toxin action and resistance in Caenorhabditis elegans. We demonstrate for the first time that a single Bt toxin can target a nematode. When fed Bt toxin, C. elegans hermaphrodites undergo extensive damage to the gut, a decrease in fertility, and death, consistent with toxin effects in insects. We have screened for and isolated 10 recessive mutants that resist the toxin's effects on the intestine, on fertility, and on viability. These mutants define five genes, indicating that more components are required for Bt toxicity than previously known. We find that a second, unrelated nematicidal Bt toxin may utilize a different toxicity pathway. Our data indicate that C. elegans can be used to undertake detailed molecular genetic analysis of Bt toxin pathways and that Bt toxins hold promise as nematicides.

scholarly journals Impact of Wheat on Soybean Cyst Nematode Population Density in Double-Cropping Soybean Production

2021 ◽  
Vol 12 ◽  
Author(s):  
Leonardo F. Rocha ◽  
Mirian F. Pimentel ◽  
John Bailey ◽  
Terry Wyciskalla ◽  
Dan Davidson ◽  
...  
Keyword(s):  
Soybean Cyst Nematode ◽  
Cropping Systems ◽  
Soil Health ◽  
Field Trials ◽  
Early Spring ◽  
Cyst Nematode ◽  
Farm Income ◽  
Double Cropping ◽  
Nematode Population Density ◽  
Beginning Of Flowering

Double-cropping is defined as producing more than one crop on the same parcel of land in a single growing season. It is reported to have many benefits when incorporated in cropping systems, including improving soil health. In some double-cropping systems, soybean is planted following winter wheat. The soybean cyst nematode (SCN) (Heterodera glycines Ichinohe) is a major soybean pathogen, and several reports suggest suppressive effects of wheat on SCN populations. Field trials were conducted from 2017 to 2018 to investigate the effect of wheat on SCN populations in double-cropping soybean. Nine fields with three levels of initial SCN populations (low, moderate, and high) were selected in Illinois. Wheat was planted in strips alternating with strips-maintained weed-free and under fallow over winter and early spring. Soybean was planted in all strips after wheat harvest. SCN egg densities were acquired at four time points: wheat establishment, post-wheat/pre-soybean, mid-soybean (R1 growth stage or beginning of flowering), and post-soybean harvest. Wheat strips reduced SCN egg densities compared with fallow strips at the R1 stage (−31.8%) and after soybean harvest (−32.7%). Double-cropping soybean with wheat has the potential to suppress SCN field populations and is a system with the potential to provide additional farm income. This study is meant to be a first step toward a better understanding of the mechanisms that govern the suppression of SCN by wheat.

scholarly journals A chromosomal assembly of the soybean cyst nematode genome

2021 ◽  
Author(s):  
Rick Masonbrink ◽  
Tom Maier ◽  
Matthew Hudson ◽  
Andrew Severin ◽  
Thomas Baum
Keyword(s):  
Soybean Cyst Nematode ◽  
Control Strategies ◽  
Cyst Nematode ◽  
Natural Resistance ◽  
Genetic Determinants ◽  
Safe Alternative ◽  
Root Cells ◽  
Long Read ◽  
Soybean Plants ◽  
Root Tissues

The soybean cyst nematode (Heterodera glycines) is a sedentary plant parasite that exceeds a billion dollars in yield losses annually. It has spread across the soybean-producing world, emerging as the primary pathogen of soybeans. This problem is exacerbated by H. glycines populations overcoming the limited sources of natural resistance in soybean and by the lack of effective and safe alternative treatments. Although there are genetic determinants that render soybean plants resistant to certain nematode genotypes, resistant soybean cultivars are increasingly ineffective because their multi-year usage has selected for virulent H. glycines populations. Successful H. glycines infection relies on the comprehensive re-engineering of soybean root cells into a syncytium, as well as the long-term suppression of host defenses to ensure syncytial viability. At the forefront of these complex molecular interactions are effectors, the proteins secreted by H. glycines into host root tissues. The mechanisms that control genomic effector acquisition, diversification, and selection are important insights needed for the development of essential novel control strategies. As a foundation to obtain this understanding, we developed a nine scaffold, 158Mb pseudomolecule assembly of the H. glycines genome using PacBio, Chicago, and Hi-C sequencing. An annotation of 22,465 genes was predicted using a Mikado pipeline informed by published short- and long-read expression data. Here we present results from our assembly and annotation of the H. glycines genome.

scholarly journals First Report of the Soybean Cyst Nematode, Heterodera glycines, on Soybean in Zhejiang, Eastern China

Plant Disease ◽  
2009 ◽  
Vol 93 (3) ◽  
pp. 319-319 ◽  
Author(s):  
J. Zheng ◽  
Y. Zhang ◽  
X. Li ◽  
L. Zhao ◽  
S. Chen
Keyword(s):  
Soybean Cyst Nematode ◽  
Heterodera Glycines ◽  
Eastern China ◽  
Mainland China ◽  
Its Region ◽  
Cyst Nematode ◽  
Northeastern China ◽  
First Report ◽  
Soybean Plants ◽  
Two Populations

The soybean cyst nematode (SCN), Heterodera glycines Ichinohe, is a destructive pest of soybean. Damage to soybean by SCN was first reported from northeastern China in 1899 (1). SCN has been documented in Anhui, Beijing, Hebei, Heilongjiang, Henan, Jiangsu, Jilin, Liaoning, Neimenggu, Shaanxi, Shandong, and Shanxi provinces in mainland China (1). These provinces are situated in the Heilongjiang and Songhuajing valleys in northeastern China and the eastern region of the Yangtze and Yellow rivers in northern China and have cold to temperate climates. In June of 2008, cyst-forming nematodes were detected in two soybean-growing areas of Hangzhou and Xiaoshan in Zhejiang Province, in subtropical eastern China. The soybean plants at the Hangzhou site showed symptoms of stunting and chlorosis, whereas no aboveground or root symptoms were observed on soybean plants at the Xiaoshan site, except for the presence of SCN females on the roots. The two populations had the same morphological and molecular characters. The cysts were lemon shaped with posterior protuberance, ambifenestrate, underbridge and bullae strongly developed, and lateral field of second-stage juveniles consisted of four incisures. The key morphometrics of cysts were fenestra length (41 to 52 μm) and width (33 to 48 μm), vulval silt (47 to 55 μm), and underbridge length (79 to 94 μm), all of which were coincident with that of SCN (2). Amplification of rDNA-internal transcribed spacer (ITS) region using primers TW81 (5′-GTT TCC GTA GGT GAA CCT GC-3′) and AB28 (5′-ATA TGC TTA AGT TCA GCG GGT-3′) yielded a PCR fragment of approximately 1,030 bp. The digestion patterns of the PCR fragments of the ITS region with AluI, AvaI, CfoI, MvaI, and RsaI showed identical restriction profiles to H. glycines (3), and the sequences exhibited 100% similarity with those of H. glycines isolates, Accession No. AY667456 from GenBank. Morphological and molecular identification confirmed that the two populations of cyst-forming nematodes from Zhejiang are SCN. To our knowledge, this is the first report of SCN in Zhejiang, now the most southern location in mainland China with confirmed infestation of SCN. References: (1) Z. X. Liu et al. Int. J. Nematol. 7:18, 1997. (2) R. H. Mulvey. Can. J. Zool. 50:1277, 1972. (3) J. Zheng et al. Russ. J. Nematol. 8:109, 2000.

scholarly journals Use of the Glomus etunicatum as biocontrol agent of the soybean cyst nematode

2021 ◽  
Vol 10 (6) ◽  
pp. e7310615132
Author(s):  
Tatiana Benedetti ◽  
Zaida Inês Antoniolli ◽  
Elisangela Sordi ◽  
Ivan Ricardo Carvalho ◽  
Edson Campanhola Bortoluzzi
Keyword(s):  
Soybean Cyst Nematode ◽  
Mycorrhizal Fungus ◽  
Arbuscular Mycorrhizal ◽  
Cyst Nematode ◽  
Initial Population ◽  
Glomus Etunicatum ◽  
Cyst Nematodes ◽  
Nematode Reproduction ◽  
Soybean Plants ◽  
Disease Pressure

This study investigated the effect of arbuscular mycorrhiza (Glomus etunicatum Becker & Gerd.), on the cyst nematode (Heterodera glycines Ichinohe), in a greenhouse. Mycorrhizal and non-mycorrhizal soybean plants were exposed to the pathogen at different initial population densities (0, 500, 1000, 2000, and 4000 nematodes eggs). Soybean growth, nematode reproduction, and the arbuscular mycorrhizal fungus’s capacity to decrease disease pressure were determined after 60 day-olds. The height of the plants was increased by 26% in the presence of arbuscular mycorrhizal fungus (AMF) despite of a higher initial population of cyst nematodes. The root length was, on average, 32.20% was greater in the presence of AMF. The number of nematodes females found in the root system of mycorrhizal plants was 28.21% lower than in non-mycorrhizal roots. These results suggest that AMF G. etunicatum acts indirectly, promoting an improvement in the nutritional plant status creating tolerance to the presence of the pathogen by soybean.

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