The focus of my research in the Mitchum Lab was the molecular basis of plant-nematode interactions with an emphasis on the interaction between the soybean cyst nematode (SCN; Heterodera glycines) and its host plant, soybean. Sedentary endoparasitic nematodes, such as SCN, are the most economically important group of plant-parasitic nematodes. Crop damages caused by SCN result to over $1 billion dollars in soybean yield loss annually in the United States alone. SCN damages the plant by attaching itself to the soybean root system, where it forms a complex feeding site (called a syncytium) and drains vital nutrients from the plant. SCN also has the ability to survive in the soil as a cyst for up to 30 years without the presence of a host, making SCN even more difficult to control. As of today there are no known effective means of controlling this pest in agricultural fields. Therefore, understanding the molecular mechanisms that are involved in the pathogenicity and host resistance to cyst nematodes is critical for developing improved disease resistance strategies.

My research project was centered to two aspects:

• The role of phytohormones in the establishment of feeding sites in plant roots. This involves studying the expression and function of genes encoding biosynthetic and catabolic enzymes, hormone signaling pathway components, and response genes in both model plants and soybean.
• Understand the function of several cyst nematode parasitism gene candidates that are expressed in the esophageal gland cells during the process of parasitism. The majority of these genes encode secreted “pioneer” proteins meaning they have no homology to any other proteins in existing databases. RNA interference, ectopic expression in plants, and yeast two-hybrid are some of the tools used to explore the role of these genes in parasitism.

Soybean cyst nematode (SCN) female on root

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