Theses and Dissertations

Issuing Body

Mississippi State University


Reichert, Nancy

Committee Member

Klink, Vincent

Committee Member

Wang, Ying

Committee Member

Li, Jiaxu

Date of Degree


Original embargo terms

Complete embargo for 2 years

Document Type

Graduate Thesis - Open Access


Biological Sciences

Degree Name

Master of Science


College of Arts and Sciences


Department of Biological Sciences


The secretory pathway of G. max performs a prominent role in its defense to H. glycines parasitism, a finding reinforced by the identification of the SNARE-associated gene ALPHA-SNAP-5 being rhg1. Other proteins performing important roles in secretion are Sec61-ALPHA, Sec61-BETA and Sec61-GAMMA which bind to form a trimeric complex that imports proteins into the ER for their eventual secretion. Comparative analyses to the Saccharomyces cerevisiae Sec61ALPHA, Sec61BETA and Sec61GAMMA proteins, respectively, shows G. max has 4 Sec61-ALPHA, 9 Sec61-BETA and4 Sec61-GAMMA proteins. At least one paralog from each gene family is expressed in H. glycines-parasitized root cells in G. max, but while undergoing a defense process. The overexpression of one selected Sec61-ALPHA, Sec61-BETA and Sec61-GAMMA in the H. glycines-susceptible genotype G. max[Williams 82/PI 518671] leads to an engineered defense response. In contrast, RNAi of the same selected Sec61-ALPHA, Sec61-BETA and Sec61-GAMMA genes in the H. glycines-resistant genotype G. max[Peking/PI 548402] leads to an engineered susceptible response. The combined opposite outcomes of the Sec61-ALPHA, Sec61-BETA and Sec61-GAMMA gene overexpression and RNAi provides evidence that they function in the defense process, consistent with the hypothesis that the G. max secretion system plays a role in its defense to H. glycines parasitism.

Available for download on Monday, May 15, 2023