Theses and Dissertations


Keshav Sharma

Issuing Body

Mississippi State University


Klink, Vincent

Committee Member

Lawrence, Gary W.

Committee Member

Lu, Shien

Committee Member

Wang, Ying

Date of Degree


Original embargo terms

Visible MSU Only 3 Years

Document Type

Dissertation - Open Access


Biological Sciences

Degree Name

Doctor of Philosophy

Degree Name

Doctor of Philosophy (Ph.D)


College of Arts and Sciences


Department of Biological Sciences


The initial interaction of vesicle and the target membrane prior to their fusion is called vesicle tethering, a process mediated by an octameric protein complex called the exocyst. The exocyst connects vesicles and binds them to phosphatidylinositol 4, 5-biphosphate (PI (4,5) P2), located on the plasma membrane. The exocyst complex is located at the target site, helping to prepare the soluble N-ethylmaleimide-sensitive fusion protein attachment protein (SNAP) receptor (SNARE) for docking and subsequent release of vesicular contents after fusion. The importance of the exocyst in cellular processes is inevitable since it performs central roles in exocytosis thereby inducing SNARE-mediated membrane fusion. The study presented here is concentrated on the role of exocyst genes during the defense response in Glycine max (soybean) against the plant- parasitic nematode Heterodera glycines known as the soybean cyst nematode (SCN). Using developmental genomics analysis, G. max root cells that have been induced by H. glycines through their pathogenic activities to develop into nurse cells known as a syncytium have been isolated by laser capture microdissection (LCM). RNA isolated from these cells undergoing resistant reactions in two different G. max genotypes have been used in gene expression profiling experiments that have led to the identification of the genes employed in this analysis. The results demonstrate the involvement of exocyst components in the defense process that G. max has toward H. glycines. Related studies also show the involvement of RPM1-INTERACTING PROTEIN 4 (RIN4) functioning in this defense process.