The fungi Beauveria bassiana and Metarhizium anisopliae are known as insect pathogens, and a number of strains of each fungus have been commercialized as microbial insecticides throughout the world. Typically, spores of either fungus germinate on the cuticle of an insect,
penetrate through that cuticle, and grow through the insect’ s body, killing it within days. Beauveria, a white-colored fungus, has been described as an endophyte of corn, coffee, tomatoes, date palm, and poppy; endophytism in corn has received much attention in recent years. There is some question about the validity of the observations of endophytism, especially when they are based upon non-DNA techniques (isolation of fungus from assumed sterile explants of plant tissue). Metarhizium has not yet been observed as an endophyte.
We undertook this study to design a PCR protocol for assessing the presence or absence of M. anisopliae and B. bassiana within three different plant species (tomato, corn, and sugar beets). These fungi had been previously transformed to express the green fluorescent protein (egfp) and our goal was to use a portion of that egfp gene as a specific marker to identify the presence or absence of the fungi in artificially inoculated plants. We explored PCR reaction conditions to optimize amplification and identification of the marker DNA.
We successfully determined the PCR conditions for egfp identification in one strain of Metarhizium, however, strains of Beauveria have not yet been successfully amplified using the
egfp identification marker.
Rebecca Kollman, ’07 Sidney, MT
Majors: Secondary Education, Biology
Sponsor: Craig Tepper