As the agriculture world continues to seek sustainable alternatives to chemical pesticides, the scientific community gets more inclined towards finding natural and eco-friendly control solutions. Among the most promising ones are entomopathogenic fungi, whose ability to infect and eliminate crop-damaging insects makes them valuable biocontrol agents. However, the evolutionary race between pathogens and the insect hosts means that these fungi are constantly adapting, with new genetic mechanisms emerging over time. With the fungi having to go through constant adaptations, there are high possibilities of evolutionary changes occurring in the genetic mechanisms that impart these fungi their insect-killing abilities. In light of that, a recent collaborative study uncovered a chromosome in Metarhizium fungi that may hold the key to understanding how these microorganisms become more effective at infecting insects, offering fresh insights into the future of environmentally friendly pest management.
How Genetics Play a Role in Infecting Insects?
Fungi belonging to the genus Metarhizium are very well acknowledged for attacking and killing a variety of plant-pathogenic insects and for being a significant biocontrol factor in different crops. In the collaborative study between Institute of Science and Technology Austria (ISTA) and Kiel University, researchers analysed the genomes of Metarhizium robertsii and Metarhizium brunneum to study any effect on the infectivity. The analysis was based on samples from an earlier experiment in which ants were exposed to both fungi. The findings were correlated to the mechanism of horizontal gene transfer which allows the movement of genetic material between unrelated organisms, including bacteria, fungi, and other species. In doing so, the genes can be exchanged that can improve survival, adaptation, and evolution by spreading useful traits such as disease resistance, new metabolic abilities, etc.
During this study, fungal geneticist Dr. Michael Habig of Kiel University identified a chromosome (exchanged between strains) which carries a set of genes that may enhance the fungus’s ability to infect the insect hosts. According to Dr. Habig, the chromosome contains hundreds of genes. So far, the team has identified 13 candidate genes that are likely to encode effector proteins capable of interacting with the insect immune system. The researchers also believe that some of these genes produce chitinases, which could help the fungus break through the insect’s protective cuticle. Professor Sylvia Cremer of ISTA noted that this process is likely going to be a key step for establishing infection.
Conclusion
The discovery of a transferable chromosome carrying genes linked to potential fungal infection in insects adds a new dimension to the insect-pathogenic fungi relationship dynamics. While many of the chromosome’s genes may remain uncharacterized, the identification of others involved in immune suppression and cuticle degradation points to mechanisms that could explain the remarkable success of Metarhizium species as natural insect killers. As researchers continue to unravel the functions of these genes, these findings could pave the way for the development of more effective and sustainable biocontrol models, reducing reliance on chemical pesticides and at the same time improving crop protection.
To learn more about fungal infections in insects and horizontal chromosome transfer, read the full article by clicking on the following link:
https://international-pest-control.com/wordpress/how-fungi-improve-their-ability-to-infect-insects/
Photo Credit: Sina Metzler & Roland Ferrigato, ISTA
