Brazilian researchers conclude genetic sequencing of fungus that works as a natural enemy to several caterpillars that are harmful to agriculture. The sequencing allows scientists to learn about the different races of the fungus Metarhizium rileyi and differentiate the most efficient strains for commercial biological control. Advance paves the way for bioproducts for biological control. The research can also help the identification of genes involved in mechanisms of resistance to fungicides, aiming at more balanced production systems. The study was led by researchers from Embrapa Soybeans, in collaboration with La Plata National University (UNLP), Argentina, and published in a journal by the American Society for Microbiology (ASM). Brazilian scientists concluded the genetic sequencing of a fungus that works as a natural enemy to several caterpillars that attack soybeans, corn and cotton. The research represents an important advance in the scientific knowledge about the fungus Metarhizium rileyi, known by soybean farmers as velvetbean-caterpillar white disease, and makes room for the development of new biological products in the medium and long run. “This fungus works as a natural enemy to several caterpillars, like velvetbean caterpillar, the soybean looper, the fall armyworm, and cotton leafworm. It infects the caterpillar by contact with the tegument and does not need to be ingested to naturally work as biological control”, explains the Embrapa researcher Daniel Sosa-Gómez, the study leader . The work was developed in Londrina, Paraná, at Embrapa Soybeans' labs, and relied on a collaboration with the La Plata National University (UNLP). “It is a fungus that occurs in several countries around the world. The sequencing allows us to learn about its different races and differentiate the most efficient strains for commercial biological control", he explains. According to the scientist, once each strain's behavior is known, it is possible to associate it with genetic identity and variations that occur in each place. Since the 1990s, Embrapa Soybeans has a collection of strains that occur in different parts of the world, such as Argentina, United States, Phillipines, Japan, Mexico and India. “By sequencing the genome and crossing information on the strains that are in our banks, we can better understand those with potential for the development of biological products, following the example of inoculants (see box), specifically the Bradirhizobium bacteria”, he details. The bioproducts The market for biological products has grown significantly in recent years and there is a prospect of expansion (see news article). Some of the bioproducts that are most widely known and adopted in Brazil include inoculants for biological nitrogen fixation. They contain bacteria that can remove nitrogen from the air and make it available for the plant (learn more on the page about about biological nitrogen fixation). The sequencing involved advanced bioinformatic techniques, with the use of specific computational tools for the reconstruction of the full genome sequence and for the collection and interpretation of molecular information related to each gene throughout the genome. “Basic research takes time because it is made from a large volume of DNA data, which is revised and organized through such tools, based on the knowledge we detain, and will facilitate the understanding of the relationship between the fungus' genes and its particularitities”, the researcher reports. The genome was filed in the public database of biological sequences, GenBank-NCBI-NIH, GenBank-NCBI-NIH, under the accession number SBHS00000000. Trying to escape fungicides Now a major challenge for the scientists is to make these biological control fungi survive fungicide applications in the farms. That is because the same products used against the soybean rust-causing fungus can also hit the caterpillar's natural enemy. Therefore, the researcher anticipates that, for the upcoming years, Embrapa will work on the selection of isolates that tolerate high doses of fungicides, such as those used to control Asian soybean rust. “Production systems are increasingly more complex and we cannot analyze pest control separately”, he affirms. That is the reason why the knowledge obtained from this research is so important: it is necessary to find alternatives to make production systems more and more balanced. “The fungus has an interesting trait: it only attacks the caterpillars, and thus has a rather selective performance, which benefits the balance in production systems in a general way”, explains Sosa-Gómez. The scientists believe that by identifying isolates of the Metarhizium fungus that tolerate high doses of the fungicides used to control the rust, it will be possible to find more balanced solutions for caterpillar control. The research also can help to identify the genes involved in fungicide resistance mechanisms. The study was published on the journal American Society for Microbiology (ASM), one of the most respected in the area worldwide, and is authored by the researchers Daniel Sosa-Gómez and Eliseu Binneck, from Embrapa Soybeans, and Cláudia López Lastra, from La Plata University, Buenos Aires, Argentina. How the fungus attacks the caterpillars With geographic distribution at a global level, the fungus Metarhizium rileyi attacks the caterpillars by initially forming a white layer (non-sporular fungus) over the insect, hence the popular name of “white disease” in the caterpillars. It is a regulating agent for the populations of the main caterpillars that affect major crops. Because of its selective and highly efficient performance in natural or agricultural conditions, the funguz has become an important biological agent for the development of bioinsecticides and the prospection of active biological components for different purposes. In the past, it used to be the basis for the development of biological control products, but it fell into disuse, and now has renewed potential for commercial exploration with the use of new techniques that allow better strain production. According to Sosa-Gómez, currently there are products base on the fungus being traded in South Africa. Photo: Daniel Sosa-Gómez Translation: Mariana Medeiros
Photo: Daniel Sosa-Gómez
Fungus Metarhizium rileyi attacks caterpillars that harm agriculture
Brazilian researchers conclude genetic sequencing of fungus that works as a natural enemy to several caterpillars that are harmful to agriculture.
The sequencing allows scientists to learn about the different races of the fungus Metarhizium rileyi and differentiate the most efficient strains for commercial biological control.
Advance paves the way for bioproducts for biological control.
The research can also help the identification of genes involved in mechanisms of resistance to fungicides, aiming at more balanced production systems.
The study was led by researchers from Embrapa Soybeans, in collaboration with La Plata National University (UNLP), Argentina, and published in a journal by the American Society for Microbiology (ASM).
Brazilian scientists concluded the genetic sequencing of a fungus that works as a natural enemy to several caterpillars that attack soybeans, corn and cotton. The research represents an important advance in the scientific knowledge about the fungus Metarhizium rileyi, known by soybean farmers as velvetbean-caterpillar white disease, and makes room for the development of new biological products in the medium and long run.
“This fungus works as a natural enemy to several caterpillars, like velvetbean caterpillar, the soybean looper, the fall armyworm, and cotton leafworm. It infects the caterpillar by contact with the tegument and does not need to be ingested to naturally work as biological control”, explains the Embrapa researcher Daniel Sosa-Gómez, the study leader . The work was developed in Londrina, Paraná, at Embrapa Soybeans' labs, and relied on a collaboration with the La Plata National University (UNLP).
“It is a fungus that occurs in several countries around the world. The sequencing allows us to learn about its different races and differentiate the most efficient strains for commercial biological control", he explains. According to the scientist, once each strain's behavior is known, it is possible to associate it with genetic identity and variations that occur in each place.
Since the 1990s, Embrapa Soybeans has a collection of strains that occur in different parts of the world, such as Argentina, United States, Phillipines, Japan, Mexico and India. “By sequencing the genome and crossing information on the strains that are in our banks, we can better understand those with potential for the development of biological products, following the example of inoculants (see box), specifically the Bradirhizobium bacteria”, he details.
The bioproducts
The market for biological products has grown significantly in recent years and there is a prospect of expansion (see news article). Some of the bioproducts that are most widely known and adopted in Brazil include inoculants for biological nitrogen fixation. They contain bacteria that can remove nitrogen from the air and make it available for the plant (learn more on the page about about biological nitrogen fixation).
The sequencing involved advanced bioinformatic techniques, with the use of specific computational tools for the reconstruction of the full genome sequence and for the collection and interpretation of molecular information related to each gene throughout the genome.
“Basic research takes time because it is made from a large volume of DNA data, which is revised and organized through such tools, based on the knowledge we detain, and will facilitate the understanding of the relationship between the fungus' genes and its particularitities”, the researcher reports. The genome was filed in the public database of biological sequences, GenBank-NCBI-NIH, GenBank-NCBI-NIH, under the accession number SBHS00000000.
Trying to escape fungicides
Now a major challenge for the scientists is to make these biological control fungi survive fungicide applications in the farms. That is because the same products used against the soybean rust-causing fungus can also hit the caterpillar's natural enemy. Therefore, the researcher anticipates that, for the upcoming years, Embrapa will work on the selection of isolates that tolerate high doses of fungicides, such as those used to control Asian soybean rust.
“Production systems are increasingly more complex and we cannot analyze pest control separately”, he affirms. That is the reason why the knowledge obtained from this research is so important: it is necessary to find alternatives to make production systems more and more balanced.
“The fungus has an interesting trait: it only attacks the caterpillars, and thus has a rather selective performance, which benefits the balance in production systems in a general way”, explains Sosa-Gómez. The scientists believe that by identifying isolates of the Metarhizium fungus that tolerate high doses of the fungicides used to control the rust, it will be possible to find more balanced solutions for caterpillar control. The research also can help to identify the genes involved in fungicide resistance mechanisms.
The study was published on the journal American Society for Microbiology (ASM), one of the most respected in the area worldwide, and is authored by the researchers Daniel Sosa-Gómez and Eliseu Binneck, from Embrapa Soybeans, and Cláudia López Lastra, from La Plata University, Buenos Aires, Argentina.
How the fungus attacks the caterpillars
With geographic distribution at a global level, the fungus Metarhizium rileyi attacks the caterpillars by initially forming a white layer (non-sporular fungus) over the insect, hence the popular name of “white disease” in the caterpillars. It is a regulating agent for the populations of the main caterpillars that affect major crops. Because of its selective and highly efficient performance in natural or agricultural conditions, the funguz has become an important biological agent for the development of bioinsecticides and the prospection of active biological components for different purposes.
In the past, it used to be the basis for the development of biological control products, but it fell into disuse, and now has renewed potential for commercial exploration with the use of new techniques that allow better strain production. According to Sosa-Gómez, currently there are products base on the fungus being traded in South Africa.
