Abstract
Entomopathogenic fungi play important roles in the control of populations of agricultural and disease vector pests in nature. The shortcomings of mycoinsecticides for pest management in the field cannot be completely overcome by improving single biocontrol properties of fungi. Therefore, enhancing the biocontrol potential of entomopathogenic fungi in multiple respects by genetic engineering is desirable. Transcription factors are usually involved in various important processes during fungal growth and pathogenesis via regulating a series of genes, and are important candidates for fungal improvement via genetic engineering. Herein, overexpression of MaSom1, a key transcription factor gene in the cAMP/PKA pathway, improves the biocontrol traits of Metarhizium acridum in multiple respects. When compared with WT, the MaSom1-overexpression strains exhibit enhanced tolerances to UV-B and heat shock, with increased mean 50% inhibition times by 66.9% and 155.2%, respectively. Advanced conidiation emerged accompanied by increased conidial yield up to 3.89 times after 3-day incubation for the MaSom1-overexpression strains compared to WT. Furthermore, when compared with WT, the virulence of the MaSom1-overexpression strains was also increased with the mean 50% lethality times reduced by 21.8% to 23.8%. Taken together, the MaSom1-overexpression improved the biocontrol potential of M. acridum in multiple respects. Our results provide insights into the application of key transcription factors for genetic engineering and offer a credible way to further improve the biocontrol potential of entomopathogenic fungi.
Highlights
As disease-causing vectors or agricultural pests, insect pests cause huge human health problems and significant economic losses worldwide [1]
Our results provide insights to improve the biocontrol potential of entomopathogenic fungi in multiple respects
The quantitative reverse transcription PCR showed that the expression levels of MaSom1 at conidial stage were increased nearly about 2.59 ± 1.21fold for OE-4, 2.84 ± 0.83-fold for OE-34, and 2.04 ± 1.11-fold for OE-55 when compared with WT (Figure 1B)
Summary
As disease-causing vectors or agricultural pests, insect pests cause huge human health problems and significant economic losses worldwide [1]. As the largest group of insect microbial pathogens, entomopathogenic fungi undertake the main missions for insect control in nature, and can infect by penetrating the host cuticle They show great biocontrol potential, along with the advantages of environmental friendliness, safety to human and animals, and their being epidemic in the insect pest population [5,6]. Some disadvantages, such as poor efficacy, high cost for producing, and susceptibilities to various adverse conditions, have delayed their wide application [5,7,8,9]. Along with the development of biological sequencing and robust technologies for fungal transformation, genetic engineering makes it possible to improve the mycoinsecticides’ efficacy and cost-effectiveness [10,11]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
