New perspectives on insect pathogens

Leger, Raymond J. St.; Wang, Chengshu; Fang, Weiguo

doi:10.1016/j.fbr.2011.04.005

Cited by 50 publications

(20 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The putative elicitin, CBEL, and CRN proteins may reflect the evolution of L. giganteum from a plant to an insect pathogen and may indicate that L. giganteum can establish symbiotic and/or pathogenic interactions with plants. This hypothesis is remarkably similar to the recent analyses indicating that entomopathogenic fungi evolved from plant pathogens and endophytes and have retained the ability to establish endophytic relationships (62)(63)(64). Combined evidence from the filamentous entomopathogens Metarhizium anisopliae and L. giganteum suggests that entomopathogenicity has evolved from plant-associated microbes in two independent and phylogenetically distant eukaryotic lineages.…”

Section: Discussionsupporting

confidence: 71%

Transcriptome Analysis of the Entomopathogenic Oomycete Lagenidium giganteum Reveals Putative Virulence Factors

Velasquez

Abiff

Fins

et al. 2014

Appl Environ Microbiol

View full text Add to dashboard Cite

A combination of 454 pyrosequencing and Sanger sequencing was used to sample and characterize the transcriptome of the entomopathogenic oomycete Lagenidium giganteum. More than 50,000 high-throughput reads were annotated through homology searches. Several selected reads served as seeds for the amplification and sequencing of full-length transcripts. Phylogenetic analyses inferred from full-length cellulose synthase alignments revealed that L giganteum is nested within the peronosporalean galaxy and as such appears to have evolved from a phytopathogenic ancestor. In agreement with the phylogeny reconstructions, full-length L. giganteum oomycete effector orthologs, corresponding to the cellulose-binding elicitor lectin (CBEL), crinkler (CRN), and elicitin proteins, were characterized by domain organizations similar to those of pathogenicity factors of plantpathogenic oomycetes. Importantly, the L. giganteum effectors provide a basis for detailing the roles of canonical CRN, CBEL, and elicitin proteins in the infectious process of an oomycete known principally as an animal pathogen. Finally, phylogenetic analyses and genome mining identified members of glycoside hydrolase family 5 subfamily 27 (GH5_27) as putative virulence factors active on the host insect cuticle, based in part on the fact that GH5_27 genes are shared by entomopathogenic oomycetes and fungi but are underrepresented in nonentomopathogenic genomes. The genomic resources gathered from the L. giganteum transcriptome analysis strongly suggest that filamentous entomopathogens (oomycetes and fungi) exhibit convergent evolution: they have evolved independently from plant-associated microbes, have retained genes indicative of plant associations, and may share similar cores of virulence factors, such as GH5_27 enzymes, that are absent from the genomes of their plant-pathogenic relatives.

show abstract

Section: Discussionsupporting

confidence: 71%

Transcriptome Analysis of the Entomopathogenic Oomycete Lagenidium giganteum Reveals Putative Virulence Factors

Velasquez

Abiff

Fins

et al. 2014

Appl Environ Microbiol

View full text Add to dashboard Cite

show abstract

“…Results from the immersion bioassay showed that all M. robertsii isolates induced Abbott-corrected mortalities among fifth instar codling moth larvae ranging from 46 to 85% (Table 2). These results are in agreement with those obtained from other laboratory studies which indicate some M. robertsii strains are highly pathogenic against insect pests (St. Leger, Wang, & Fang, 2011;Lopes, Souza, Oliveira, & Faria, 2013). In the current study, conidial suspension of the strain of F. oxysporum used in the immersion bioassay induced up to 77% mortality among fifth instar codling moth larvae.…”

supporting

confidence: 95%

Isolation and pathogenicity of some South African entomopathogenic fungi (Ascomycota) against eggs and larvae ofCydia pomonella(Lepidoptera: Tortricidae)

Abaajeh

Nchu

2015

Biocontrol Science and Technology

View full text Add to dashboard Cite

Virulent entomopathogenic fungal strains against Cydia pomonella (Lepidoptera: Tortricidae) were isolated and identified in the Western Cape Province of South Africa. Thirty-nine isolates belonging to six species were obtained using the insect bait method. Generally, Metarhizium robertsii (Ascomycota: Hypocreales) was the most frequently encountered species representing 51% of the total number of isolates collected from the soil samples. This is the first report of M. robertsii from southern Africa. Mortality data from an immersion bioassay indicated that the 39 fungal isolates were pathogenic against fifth instar larvae of C. pomonella inducing 47-85% insect mortalities. Two M. robertsii strains, MTL151 and GW461, induced 85% larval mortality and were selected for further evaluations. The exposure of freshly laid eggs to wax papers that were pre-treated with fungal spores ranging from 10 3 to 10 8 spores ml −1 of MTL151 and GW461 resulted in a significant reduction of egg hatchabilities, from 95 to 66% and 93 to 71%, respectively as spore concentration increased. First instar larval neonates were exposed to apples that were pre-sprayed topically with varied conidia suspensions (10 3 −10 8 spores ml −1 ). The mean percentage of participating apples with larvae in their cores/flesh significantly reduced from 53 to 10% (MTL151) and 76 to 10% (GW461) of 10 apples, and a concurrent decrease in the incidence of apple fruit rot was observed as conidia concentration increased. Up to 90% of apples treated with 1 × 10 8 spores ml −1 had no larvae present in their cores and this result compared favourably with the commercial pesticide Fruitfly®, containing the active ingredient cypermethrin (20 g/l) used at a recommended dose of 0.25 ml/250 ml of water.

show abstract

“…However, the extensively melanized insects killed by the transgenic strain were unfavorable to fungal growth and sporulation, reducing recombinant fungus transmission. This facilitated approval from the United States Environmental Protection Agency for a field trial with a Pr1‐overexpressing strain of M. robertsii , thus setting a precedent paving the way for future trials . This trial was also the first usage in the field of M. robertsii tagged with green fluorescent protein (GFP), and the fluorescent tag enabled the serendipitous discovery that M. robertsii is rhizosphere competent …”

Section: Engineering Enhanced Virulencementioning

confidence: 99%

Genetically engineering better fungal biopesticides

Lovett

Leger

2017

Pest Management Science

110

View full text Add to dashboard Cite

Microbial insect pathogens offer an alternative means of pest control with the potential to wean us off our heavy reliance on chemical pesticides. Insect pathogenic fungi play an important natural role in controlling disease vectors and agricultural pests. Most commercial products employ Ascomycetes in the genera Metarhizium and Beauveria. However, their utilization has been limited by inconsistent field results as a consequence of sensitivity to abiotic stresses and naturally low virulence. Other naturally occurring biocontrol agents also face these hurdles to successful application, but the availability of complete genomes and recombinant DNA technologies have facilitated design of multiple fungal pathogens with enhanced virulence and stress resistance. Many natural and synthetic genes have been inserted into entomopathogen genomes. Some of the biggest gains in virulence have been obtained using genes encoding neurotoxic peptides, peptides that manipulate host physiology and proteases and chitinases that degrade the insect cuticle. Prokaryotes, particularly extremophiles, are useful sources of genes for improving entomopathogen resistance to ultraviolet (UV) radiation. These biological insecticides are environmentally friendly and cost-effective insect pest control options. © 2017 Society of Chemical Industry.

show abstract

New perspectives on insect pathogens

Cited by 50 publications

References 42 publications

Transcriptome Analysis of the Entomopathogenic Oomycete Lagenidium giganteum Reveals Putative Virulence Factors

Transcriptome Analysis of the Entomopathogenic Oomycete Lagenidium giganteum Reveals Putative Virulence Factors

Isolation and pathogenicity of some South African entomopathogenic fungi (Ascomycota) against eggs and larvae ofCydia pomonella(Lepidoptera: Tortricidae)

Genetically engineering better fungal biopesticides

Contact Info

Product

Resources

About