Potato genomics three ways: quantification of endoreduplication in tubers, a romp through the transposon terrain, and elucidation of flower color regulation

Investigations of potato (Solanum tuberosum) have been hampered by its complicated genetics and high genetic load. This dissertation applies genome reduction techniques to investigate a broad swath of genomic and physiological phenomena. It begins with the presentation and evaluation of a protocol to characterize endoreduplication within potato tubers, demonstrating substantial variation between tissue types and among wild species which may facilitate research into the genesis and growth of these starchy underground stems. Next, we transitioned to explore the distribution and consequences of a specific class of transposable element, Miniature Inverted Transposable Elements (MITEs), showing that they comprise approximately 5% of the potato genome, occur more frequently in genes with stress-related functions, and may be associated with changes, especially decreases, in gene expression. We then combined homology and sparsity based approaches to predict recent MITE activity, identifying five families as especially active. Finally, we expose the gene underlying the potato flower color locus, a homolog of AN2, while showing the effects it exerts on the flavonoid biosynthesis and fruit ripening pathways. This region was shown to be particularly dynamic, replete with MITEs and structural variants which we hypothesize to be the ultimate cause of differences in AN2 expression within the germplasm we examined. While the separate topics of this dissertation are quite disparate, each addresses an important topic in potato genetics, the in-depth study of which is only possible through the utilization of genomic reduction approaches to acquire homozygous genotypes for study and currently available genomic resources.

Name thesis:degree_name

Ph. D.

Level thesis:degree_level

doctoral

Discipline thesis:degree_discipline

Horticulture

Department dc:contributor.department

Horticulture

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

2018

Author dc:creator

• Laimbeer, Francis Parker Effingham

Chair dc:contributor.committeechair

• Veilleux, Richard E.

Committee members dc:contributor.committeemember

• Saghai-Maroof, Mohammad A.
• Bombarely Gomez, Aureliano
• Tokuhisa, James G.

• Solanum tuberosum
• potato
• endoreduplication
• flow cytometry
• ploidy
• transposons
• MITEs
• anthocyanins

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Dc Identifier Other

vt_gsexam:16698

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/84480