Date of Graduation


Document Type


Degree Name

Master of Science in Entomology (MS)

Degree Level





Ashley Dowling

Committee Member

John Rupe

Second Committee Member

Ken Korth


agriculture, nematode, plant resistance, transgenic plant


Soybean (Glycine max), an important economic crop native to East Asia, is grown worldwide for its edible beans. Soybean plants are vulnerable to a wide range of diseases, and nematodes are among the worst pests of soybean. The southern root-knot nematode (Meloidogyne incognita) and soybean cyst nematode (Heterodera glycines) are both notable nematode pests of soybean, with the soybean cyst nematode causing more than 30% of total yield loss in the US. Numerous attempts have been made to control soybean nematodes over the past several decades, and genetic engineering technology has received a lot of attention in recent years. Plant elicitor peptides (Peps) are endogenous polypeptides consisting of amino acids that can trigger innate immune defense in plants and are present in various plant species, including soybean. GmPep3 are plant elicitor peptides present in soybean and the gene GmPROPEP3 regulates the synthesis of GmPep3 in soybean. In this study, two independent nematode bioassays were conducted to investigate whether GmPep3 treatment and the insertion of GmPROPEP3 in susceptible soybean cultivar Magellan could enhance soybean defense towards the southern root-knot nematode and the soybean cyst nematode, and whether different treatments on soybean have any effect on soybean growth. According to the results, the GmPep3 treatment and the insertion of GmPROPEP3 in Magellan have no negative effect on soybean growth. However, whether the treatments have any positive effects on soybean growth needs further investigation. The root-knot nematode bioassay results suggested that there were no significant differences in egg number between treatment groups, while the soybean cyst nematode result indicated that both transgenic lines were resistant to soybean cyst nematodes. However, the data presented in this study is insufficient, and future experiments are necessary in order to support the current conclusion.