ANNOUNCING DEFENSE SEMINAR: EMILY ROGGENKAMP
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Email“GENETIC INVESTIGATION OF THE MAIZE PATHOGEN PHYLLACHORA MAYDIS”
Genetics and Genome Sciences
Defense Seminar
June 28, 2024
9:30 AM
FST Room 162
EMAIL LAUREN COLBY FOR ZOOM INFO
Committee:
Dr. Martin Chilvers (PI)
Dr. C. Robin Buell
Dr. Addie Thompson
Dr. Frances Trail
Phyllachora maydis is a fungal pathogen that causes the disease tar spot of maize (Zea mays). Though P. maydis was first identified in Mexico in 1904, the pathogen has only been detected in the United States since 2015. Since this introduction to the US, P. maydis has been observed in many states across the Midwest and Canada causing devastating yield losses under conducive conditions. P. maydis produces black stromata on maize foliage that resemble spots of tar. A necrotic lesion can often form surrounding the tar spot stroma termed the fisheye lesion. Much speculation has arisen surrounding the causal agents of this lesion associated with P. maydis. Additionally, P. maydis is considered an obligate biotroph that grows on living host tissue and cannot be cultured axenically and artificial inoculations in controlled environments have previously not been reproducible. Thus, previous understanding of this pathogen was scarce, and related species within the classified order had not been extensively studied. Therefore, this dissertation has focused on providing methods and initial genetic information for future understanding of the tar spot of maize pathosystem. First, a detection assay specific to P. maydis was developed. Second, the P. maydis genome and annotation were improved providing gene content information. Next, maize differential expression was investigated in response to the tar spot pathogen. Lastly, microbial communities were explored to understand the fisheye lesion development between countries. Overall, these studies provide tools and knowledge which has furthered the research on this pathosystem.
