Theses and Dissertations

Issuing Body

Mississippi State University


Reichert, Nancy A.

Committee Member

Klink, Vincent

Committee Member

Wang, Ying

Committee Member

Lu, Shien

Committee Member

Li, Jiaxu

Date of Degree


Original embargo terms

Complete embargo for 2 years

Document Type

Dissertation - Open Access



Degree Name

Doctor of Philosophy (Ph.D)


College of Arts and Sciences


Department of Biological Sciences


An analysis of Glycine max homologs of the symbiosis genes DOES NOT MAKE INFECTIONS (DMI) DMI1, DMI2 and DMI3 was carried out as it relates to the defense response to Heterodera glycines parasitism. Transgenic analyses of the DMI1, DMI2 and DMI3 for overexpression showed decreased H. glycines parasitism while the analyses for RNAi showed increased H. glycines parasitism. The combination of decreased parasitism in the H. glycines-susceptible genotype G. max [Williams 82/PI 518671] and increased parasitism in the H. glycines resistant genotype G. max [Peking/PI 548402] is taken as the genes function in the defense process at some level. Prior analyses have shown that mitogen activated protein kinases (MAPKs) function in the defense response that has to H. glycines. A preliminary RNA seq analysis of MAPK3-1 and MAPK3-2 overexpressing roots reveal increased relative transcript abundance of DMI3, but only in the MAPK3-1 overexpressing roots. Additionally, examination of the expression profiles of two G. max MAPK3-1 and MAPK3-2 showed that their relative transcript abundances in some cases are influenced by DMI1, DMI2 and DMI3 expression. Taken together, the results show that the G. max DMI1, DMI2 and DMI3 function in the defense response to H. glycines and appear to involve MAPKs.