Cross-Resistance of the Codling Moth against Different Isolates of Cydia pomonella Granulovirus Is Caused by Two Different but Genetically Linked Resistance Mechanisms

Cydia pomonella granulovirus (CpGV) is a widely used biological control agent of the codling moth. Recently, however, the codling moth has developed different types of field resistance against CpGV isolates. Whereas type I resistance is Z chromosomal inherited and targeted at the viral gene pe38 of isolate CpGV-M, type II resistance is autosomal inherited and targeted against isolates CpGV-M and CpGV-S. Here, we report that mixtures of CpGV-M and CpGV-S fail to break type II resistance and is expressed at all larval stages. Budded virus (BV) injection experiments circumventing initial midgut infection provided evidence that resistance against CpGV-S is midgut-related, though fluorescence dequenching assay using rhodamine-18 labeled occlusion derived viruses (ODV) could not fully elucidate whether the receptor binding or an intracellular midgut factor is involved. From our peroral and intra-hemocoel infection experiments, we conclude that two different (but genetically linked) resistance mechanisms are responsible for type II resistance in the codling moth: resistance against CpGV-M is systemic whereas a second and/or additional resistance mechanism against CpGV-S is located in the midgut of CpR5M larvae.

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Transcriptome of Cydia pomonella granulovirus in susceptible and type I resistant codling moth larvae

Journal of General Virology ◽

10.1099/jgv.0.001566 ◽

2021 ◽

Vol 102 (3) ◽

Cited By ~ 1

Author(s):

Jörg T. Wennmann ◽

Diana Pietruska ◽

Johannes A. Jehle

Keyword(s):

Gene Expression ◽

Fat Body ◽

Cydia Pomonella ◽

Codling Moth ◽

Viral Gene ◽

Type I ◽

Pome Fruit ◽

Type I Resistance ◽

Cydia Pomonella Granulovirus

The baculovirus Cydia pomonella granulovirus (CpGV) is a biocontrol agent used worldwide against the codling moth (CM), Cydia pomonella L., a severe pest in organic and integrated pome fruit production. Its successful application is increasingly challenged by the occurrence of CM populations resistant to commercial CpGV products. Whereas three types (I–III) of CpGV resistance have been identified, type I resistance compromising the efficacy of CpGV-M, the so-called Mexican isolate of CpGV, is assumed to be the most widely distributed resistance type in Central Europe. Despite the wide use of CpGV products as biocontrol agents, little information is available on gene-expression levels in CM larvae. In this study, the in vivo transcriptome of CpGV-M infecting susceptible (CpS) and resistant (CpRR1) CM larvae was analysed at 24, 48, 72, 96 and 120 hours post infection in the midgut and fat body tissue by using a newly developed microarray covering all ORFs of the CpGV genome. According to their transcript abundance, the CpGV genes were grouped into four temporal clusters to which groups of known and unknown function could be assigned. In addition, sets of genes differentially expressed in the midgut and fat body were found in infected susceptible CpS larvae. For the resistant CpRR1 larvae treated with CpGV-M, viral entry in midgut cells could be confirmed from onset but a significantly reduced gene expression, indicating that type I resistance is associated with a block of viral gene transcription and replication.

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Genome Analysis of A Novel South African Cydia pomonella granulovirus (CpGV-SA) with Resistance-Breaking Potential

Viruses ◽

10.3390/v11070658 ◽

2019 ◽

Vol 11 (7) ◽

pp. 658 ◽

Cited By ~ 1

Author(s):

Boitumelo Motsoeneng ◽

Michael D. Jukes ◽

Caroline M. Knox ◽

Martin P. Hill ◽

Sean D. Moore

Keyword(s):

South African ◽

Complete Genome ◽

Cydia Pomonella ◽

Codling Moth ◽

Type I ◽

Nucleotide Polymorphisms ◽

Pome Fruit ◽

Single Nucleotide ◽

Resistance Breaking ◽

Cydia Pomonella Granulovirus

The complete genome of an endemic South African Cydia pomonella granulovirus isolate was sequenced and analyzed. Several missing or truncated open reading frames (ORFs) were identified, including a 24 bp deletion in the pe38 gene which is reported to be associated with type I resistance-breaking potential. Comparison of single nucleotide polymorphisms (SNPs) with five other fully sequenced CpGV isolates identified 67 unique events, 47 of which occurred within ORFs, leading to several amino acid changes. Further analysis of single nucleotide variations (SNVs) within CpGV-SA revealed that this isolate consists of mixed genotypes. Phylogenetic analysis using complete genome sequences placed CpGV-SA basal to M, I12 and E2 and distal to S and I07 but with no distinct classification into any of the previously defined CpGV genogroups. These results suggest that CpGV-SA is a novel and genetically distinct isolate with significant potential as a biopesticide for management of codling moth (CM), not only in South Africa, but potentially in other pome fruit producing countries, particularly where CM resistance to CpGV has been reported.

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Importance of the Host Phenotype on the Preservation of the Genetic Diversity in Codling Moth Granulovirus

Viruses ◽

10.3390/v11070621 ◽

2019 ◽

Vol 11 (7) ◽

pp. 621 ◽

Cited By ~ 2

Author(s):

Graillot ◽

Blachere-López ◽

Besse ◽

Siegwart ◽

López-Ferber

Keyword(s):

Genetic Diversity ◽

Cydia Pomonella ◽

Codling Moth ◽

Type I ◽

Host Genotype ◽

Host Colony ◽

Type I Resistance ◽

Cydia Pomonella Granulovirus ◽

Marker Virus ◽

Mexican Isolate

To test the importance of the host genotype in maintaining virus genetic diversity, five experimental populations were constructed by mixing two Cydia pomonella granulovirus isolates, the Mexican isolate CpGV-M and the CpGV-R5, in ratios of 99% M + 1% R, 95% M + 5% R, 90% M + 10% R, 50% M + 50% R, and 10% M + 90% R. CpGV-M and CpGV-R5 differ in their ability to replicate in codling moth larvae carrying the type I resistance. This ability is associated with a genetic marker located in the virus pe38 gene. Six successive cycles of replication were carried out with each virus population on a fully-permissive codling moth colony (CpNPP), as well as on a host colony (RGV) that carries the type I resistance, and thus blocks CpGV-M replication. The infectivity of offspring viruses was tested on both hosts. Replication on the CpNPP leads to virus lineages preserving the pe38 markers characteristic of both isolates, while replication on the RGV colony drastically reduces the frequency of the CpGV-M pe38 marker. Virus progeny obtained after replication on CpNPP show consistently higher pathogenicity than that of progeny viruses obtained by replication on RGV, independently of the host used for testing.

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Partial Loss of Inheritable Type I Resistance of Codling Moth to Cydia pomonella granulovirus

Viruses ◽

10.3390/v11060570 ◽

2019 ◽

Vol 11 (6) ◽

pp. 570 ◽

Cited By ~ 1

Author(s):

Jiangbin Fan ◽

Jörg Wennmann ◽

Johannes Jehle

Keyword(s):

Current Knowledge ◽

Full Range ◽

Cydia Pomonella ◽

Codling Moth ◽

Single Pair ◽

Type I ◽

Partial Loss ◽

Resistance Level ◽

Type I Resistance ◽

Cydia Pomonella Granulovirus

Current knowledge of the field resistance of codling moth (CM, Cydia pomonella, L) against Cydia pomonella granulovirus (CpGV) is based mainly on the interaction between the Mexican isolate CpGV-M and CpRR1, a genetically homogeneous CM inbreed line carrying type I resistance. The resistance level of laboratory-reared CpRR1 to CpGV-M was recently found to have decreased considerably, compared to the initially high resistance. To understand the background of this phenomenon, CpRR1 larvae were exposed over several generations to CpGV-M for re-selection of the original resistance level. After five and seven generations of selection, new CpRR1_F5 and CpRR1_F7 lines were established. The resistance ratio of these selected lines was determined by full range bioassays. The CpRR1_F5 strain regained a higher level of resistance against CpGV up to 104-fold based on LC50 values compared to susceptible larvae (CpS), which indicated that the absence of virus selection had resulted in a reduction of resistance under laboratory rearing conditions. In addition, some fitness costs of fecundity were observed in CpRR1_F5. Single-pair crossings between CpRR1_F5 or CpRR1_F7 with susceptible CpS moths revealed a dominant but not fully sex-linked inheritance, which suggests a partial loss of previous resistance traits in CpRR1.

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Novel resistance to Cydia pomonella granulovirus (CpGV) in codling moth shows autosomal and dominant inheritance and confers cross-resistance to different CpGV genome groups

PLoS ONE ◽

10.1371/journal.pone.0179157 ◽

2017 ◽

Vol 12 (6) ◽

pp. e0179157 ◽

Cited By ~ 13

Author(s):

Annette J. Sauer ◽

Eva Fritsch ◽

Karin Undorf-Spahn ◽

Petr Nguyen ◽

Frantisek Marec ◽

...

Keyword(s):

Cydia Pomonella ◽

Codling Moth ◽

Cross Resistance ◽

Dominant Inheritance ◽

Cydia Pomonella Granulovirus

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A Third Type of Resistance to Cydia pomonella Granulovirus in Codling Moths Shows a Mixed Z-Linked and Autosomal Inheritance Pattern

Applied and Environmental Microbiology ◽

10.1128/aem.01036-17 ◽

2017 ◽

Vol 83 (17) ◽

Cited By ~ 16

Author(s):

A. J. Sauer ◽

S. Schulze-Bopp ◽

E. Fritsch ◽

K. Undorf-Spahn ◽

J. A. Jehle

Keyword(s):

Biocontrol Agent ◽

Cydia Pomonella ◽

Codling Moth ◽

Field Resistance ◽

Type I ◽

Pome Fruit ◽

Content Type ◽

Genome Group ◽

Cydia Pomonella Granulovirus ◽

Autosomal Inheritance

ABSTRACT Different isolates of Cydia pomonella granulovirus (CpGV) are used worldwide to control codling moth larvae (Cydia pomonella) in pome fruit production. Two types of dominantly inherited field resistance of C. pomonella to CpGV have been recently identified: Z-chromosomal type I resistance and autosomal type II resistance. In the present study, a CpGV-resistant C. pomonella field population (termed SA-GO) from northeastern Germany was investigated. SA-GO individuals showed cross-resistance to CpGV isolates of genome group A (CpGV-M) and genome group E (CpGV-S), whereas genome group B (CpGV-E2) was still infective. Crossing experiments between individuals of SA-GO and the susceptible C. pomonella strain CpS indicated the presence of a dominant autosomal inheritance factor. By single-pair inbreeding of SA-GO individuals for two generations, the genetically more homogenous strain CpRGO was generated. Resistance testing of CpRGO neonates with different CpGV isolates revealed that isolate CpGV-E2 and isolates CpGV-I07 and -I12 were resistance breaking. When progeny of hybrid crosses and backcrosses between individuals of resistant strain CpRGO and susceptible strain CpS were infected with CpGV-M and CpGV-S, resistance to CpGV-S appeared to be autosomal and dominant for larval survivorship but recessive when success of pupation of the hybrids was considered. Inheritance of resistance to CpGV-M, however, is proposed to be both autosomal and Z linked, since Z linkage of resistance was needed for pupation. Hence, we propose a further type III resistance to CpGV in C. pomonella, which differs from type I and type II resistance in its mode of inheritance and response to CpGV isolates from different genome groups. IMPORTANCE The baculovirus Cydia pomonella granulovirus (CpGV) is registered and applied as a biocontrol agent in nearly all pome fruit-growing countries worldwide to control codling moth caterpillars in an environmentally friendly manner. It is therefore the most widely used commercial baculovirus biocontrol agent. Since 2005, field resistance of codling moth to CpGV products has been observed in more than 40 field plantations in Europe, threatening organic and integrated apple production. Knowledge of the inheritance and mechanism(s) of resistance is indispensable for the understanding of host response to baculovirus infection on the population level and the coevolutionary arms race between virus and host, as well as for the development of appropriate resistance management strategies. Here, we report a codling moth field population with a new type of resistance, which appears to follow a highly complex inheritance in regard to different CpGV isolates.

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CpGV-M Replication in Type I Resistant Insects: Helper Virus and Order of Ingestion Are Important

Viruses ◽

10.3390/v13091695 ◽

2021 ◽

Vol 13 (9) ◽

pp. 1695

Author(s):

Aurélie Hinsberger ◽

Christine Blachère-Lopez ◽

Caroline Knox ◽

Sean Moore ◽

Tamryn Marsberg ◽

...

Keyword(s):

Genetic Diversity ◽

Cydia Pomonella ◽

Codling Moth ◽

Helper Virus ◽

Multiple Infection ◽

Multiple Infections ◽

Type I ◽

Key Factor ◽

Virus Genotypes ◽

Cydia Pomonella Granulovirus

The genetic diversity of baculoviruses provides a sustainable agronomic solution when resistance to biopesticides seems to be on the rise. This genetic diversity promotes insect infection by several genotypes (i.e., multiple infections) that are more likely to kill the host. However, the mechanism and regulation of these virus interactions are still poorly understood. In this article, we focused on baculoviruses infecting the codling moth, Cydia pomonella: two Cydia pomonella granulovirus genotypes, CpGV-M and CpGV-R5, and Cryptophlebia peltastica nucleopolyhedrovirus (CrpeNPV). The influence of the order of ingestion of the virus genotypes, the existence of an ingestion delay between the genotypes and the specificity of each genotype involved in the success of multiple infection were studied in the case of Cydia pomonella resistance. To obtain a multiple infection in resistant insects, the order of ingestion is a key factor, but the delay for ingestion of the second virus is not. CrpeNPV cannot substitute CpGV-R5 to allow replication of CpGV-M.

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Novel Diversity and Virulence Patterns Found in New Isolates of Cydia pomonella Granulovirus from China

Applied and Environmental Microbiology ◽

10.1128/aem.02000-19 ◽

2019 ◽

Vol 86 (2) ◽

Author(s):

Jiangbin Fan ◽

Jörg T. Wennmann ◽

Dun Wang ◽

Johannes A. Jehle

Keyword(s):

Biocontrol Agent ◽

Control Strategies ◽

Cydia Pomonella ◽

Codling Moth ◽

Future Application ◽

Type I ◽

Resistance Breaking ◽

Control Options ◽

Type I Resistance ◽

Cydia Pomonella Granulovirus

ABSTRACT Cydia pomonella granulovirus (CpGV) is successfully used worldwide as a biocontrol agent of the codling moth (CM) (Cydia pomonella). The occurrence of CM populations with different modes of resistance against commercial CpGV preparations in Europe, as well as the invasiveness of CM in China, threatening major apple production areas there, requires the development of new control options. Utilizing the naturally occurring genetic diversity of CpGV can improve such control strategies. Here, we report the identification of seven new CpGV isolates that were collected from infected CM larvae in northwest China. Resistance testing using a discriminating CpGV concentration and the determination of the median lethal concentration (LC50) were performed to characterize their levels of virulence against susceptible and resistant CM larvae. The isolates were further screened for the presence of the 2 × 12-bp-repeat insertion in CpGV gene pe38 (open reading frame 24 [ORF24]), which was shown to be the target of type I resistance. It was found that three isolates, CpGV-JQ, -KS1, and -ZY2, could break type I resistance, although delayed mortality was observed in the infection process. All isolates followed the pe38 model of breaking type I resistance, except for CpGV-WW, which harbored the genetic factor but failed to overcome type I resistance. However, CpGV-WW was able to overcome type II and type III resistance. The bioassay results and sequencing data of pe38 support previous findings that pe38 is the major target for type I resistance. The new isolates show some distinct virulence characteristics when infection of different CM strains is considered. IMPORTANCE CpGV is a highly virulent pathogen of the codling moth (CM). It is registered and widely applied as a biocontrol agent in nearly all apple-growing countries worldwide. The emergence of CpGV resistance and the increasing lack of chemical control options require improvements to current control strategies. Natural CpGV isolates, as well as resistance-breaking isolates selected in resistant CM strains, have provided resources for improved resistance-breaking CpGV products. Here, we report novel CpGV isolates collected in China, which have new resistance-breaking capacities and may be an important asset for future application in the biological control of codling moths.

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Genome-Wide Selective Signature Analysis Revealed Insecticide Resistance Mechanisms in Cydia pomonella

Insects ◽

10.3390/insects13010002 ◽

2021 ◽

Vol 13 (1) ◽

pp. 2

Author(s):

Wen-Ting Dai ◽

Jin Li ◽

Li-Ping Ban

Keyword(s):

Insecticide Resistance ◽

Insect Pest ◽

Glycine Receptor ◽

Cydia Pomonella ◽

Resistance Management ◽

Codling Moth ◽

Resistance Mechanisms ◽

Expression Level ◽

Invasive Pest ◽

Cross Resistance

The codling moth, Cydia pomonella L. (Lepidoptera, Tortricidae), is a serious invasive pest of pome fruits. Currently, C. pomonella management mainly relies on the application of insecticides, which have driven the development of resistance in the insect. Understanding the genetic mechanisms of insecticide resistance is of great significance for developing new pest resistance management techniques and formulating effective resistance management strategies. Using existing genome resequencing data, we performed selective sweep analysis by comparing two resistant strains and one susceptible strain of the insect pest and identified seven genes, among which, two (glycine receptor and glutamate receptor) were under strong insecticide selection, suggesting their functional importance in insecticide resistance. We also found that eight genes including CYP6B2, CYP307a1, 5-hydroxytryptamine receptor, cuticle protein, and acetylcholinesterase, are potentially involved in cross-resistance to azinphos-methyl and deltamethrin. Moreover, among several P450s identified as positively selected genes, CYP6B2, CYP4C1, and CYP4d2 showed the highest expression level in larva compared to other stages tested, and CYP6B2 also showed the highest expression level in midgut, supporting the roles they may play in insecticide metabolism. Our results provide several potential genes that can be studied further to advance understanding of complexity of insecticide resistance mechanisms in C. pomonella.

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