Theses and Dissertations

Issuing Body

Mississippi State University


Klink, Vincent

Committee Member

Gordon, Donna M.

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



Degree Name

Master of Science

Degree Name

Doctor of Philosophy (Ph.D)


College of Arts and Sciences


College of Agriculture and Life Sciences


Department of Biological Sciences


College of Agriculture and Life Sciences


The histone 2A (H2A) variant Z (H2A.Z) regulates gene expression, replacing H2A predominately at +1 nucleosomes. Whereas, H2A.Z can act as either a positive or negative transcriptional regulator, this research focuses on its transcriptional activation role. This thesis focuses on examining the Glycine max HTA9 gene family (H2A.Z9). The Arabidopsis thaliana HTA9 protein sequence was used to query the G. max proteome resulting in identification of five H2A.Z9 (H2A.Z9-1-5) paralogs. H2A.Z9-1, H2A.Z9-2, H2A.Z9-4, and H2A.Z9-5 are expressed within Heterodera glycines-parasitized root cells undergoing defense. All 5 paralogs, including H2A.Z9-3, were studied in transgenic-functional analyses. Data demonstrates that H2A.Z9 overexpression leads to a 60-70% reduction in H. glycines- parasitism with no effect on root growth. In contrast, H2A.Z9 knockdown by RNAi results in a 3.5-5.0-fold increase in H. glycines-parasitism with no effect on root growth. These results demonstrate that H2A.Z9 is important to G. max defense toward H. glycines-parasitism and indicate possible redundant or specific roles for each paralog.


Teaching Assistantship, Department of Biological Sciences

Available for download on Monday, May 15, 2023