Genetically engineering better fungal biopesticides

Abstract

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.

Soil Application of Metarhizium anisopliae JEF-314 Granules to Control, Flower Chafer Beetle, Protaetia brevitarsis seulensis

“…In addition to being environmentally-friendly, the price of commercial Metharizium spp. is similar to that of conventional chemical insecticides [22].…”

“…An attractive alternative is the use of entomopathogenic fungi, with no or minimal negative effects to human health and the environment. These insect pathogens often cause epizootic outbreaks in nature and are very effective since they directly penetrate the insect cuticle and can therefore be used as contact insecticides [21,22]. In addition to being environmentally-friendly, the price of commercial Metharizium spp.…”

Genetic Variation of Traits in Natural Enemies Relevant for Biological Control: A Systematic Review

“…More recently, there is increased attention on exploiting the large amount of intraspecific variation between, and even within, populations (Kruitwagen et al, 2018;Lommen et al, 2017). Recent studies have also suggested the use of genetic modification for increased effectiveness of BCAs, particularly in fungal and pathogen-based agents (Karabörklü et al, 2018;Lovett and St. Leger, 2018;St. Leger and Wang, 2010), as well as insects (Poppy and Powell, 2009;Routray et al, 2016).…”

Transformation of Entomopathogenic Fungi: A Methodological Review

“…Чаще всего в геном грибов встраивают последовательности, кодирующие различные факторы вирулентности, такие как секретируемые формы токсинов, способных приводить к быстрой гибели зараженного насекомого, различные формы хитиназ, протеиназ и гидролаз, способствующих более эффективному заражению насекомых и распространению патогена. Эффективное увеличение вирулентности наблюдалось как при встраивании синтетически созданных последовательностей, так и генов энтомопатогенных грибов других видов, последовательностей самого насекомого-хозяина, а также генов различных хищных насекомых (например, пауков или скорпионов) (Lovett, Leger, 2018).…”