Somatic embryogenesis is the conversion of a somatic cell to a embryogenic cell,
effectively creating a true clone. The Phytocyanin-like arabinogalactan (PLA) protein has been
shown to enhance somatic embryogenesis of plant tissue in multiple plan species. Although the
details of how PLA is involved in somatic embryogenesis are not known, its effectiveness makes
the PLA protein a potential treatment to facilitate embryo formation in plant tissue culture.
Furthermore, the non-glycosylated form of the protein is still functional, which opens the door
for utilizing bacteria as an expression system to produce PLA protein. This thesis documents an
effort to express Dioscorea rotundata PLA proteins in E. coli in order to promote somatic
embryogenesis in yam tissue. Yam is an important ‘orphan crop’ of sub-Saharan Africa, where
this technology will contribute to propagation systems being developed for this plant. The work
starts with the identification of D. rotundata PLA genes and progressed to initial attempts at
expression of DrPLA proteins in E. coli. Appendices of this thesis also describe assistance with
other projects including characterization of yam culture ‘contaminants’ and likely endosymbionts
as well as several other side projects.
