Abstract Detail

Recent Topics Posters

Eserman, Lauren [1], Leebens-Mack, Jim [2].

Evolution and development of tubers in sweet potato and other morning glories.

The repeated evolution of complex morphological traits has long been of interest to evolutionary biologists. In morning glories (ca. 700 species), species that produce starch-rich tuberous storage roots, such as sweet potato, are often more closely related to species that produce only fibrous roots than they are to other tuber-forming species. It appears that this trait has been independently derived multiple times; however, it is unclear whether having fibrous or tuberous roots is the ancestral condition in morning glories. Therefore, we are interested in understanding whether the molecular components of tuber formation are shared across all morning glories or whether tuber formation has evolved independently multiple times. This question is being addressed using two main approaches, transcriptome sequencing and evaluations of root anatomy. Pairs of closely related species were sampled broadly from across the morning glory phylogeny. Both early developing tuberous roots and fibrous roots were sampled from tuber-forming species and only fibrous roots were sampled from species that do not make tubers for transcriptome and anatomical analyses. Previous work so far implicates the involvement of two genes in sweet potato tuber formation. One of these genes (IbMADS1, a MADS-box transcription factor) is highly expressed in tubers compared to fibrous roots; in contrast, the other gene (IbEXP1, an α-expansin gene) is highly expressed in fibrous roots and other vegetative tissue compared to tubers. Therefore, if the molecular building blocks for tuber formation are present in all morning glories, we expect to see similar patterns of up- and down-regulation of these genes in species from across the morning glory phylogeny. In contrast, if this pattern of differential gene expression is not shared across all species, this would suggest that tubers have been independently derived multiple times in the evolutionary history of morning glories. These predictions will be discussed in light of gene expression data as well as comparisons of root anatomy.

1 - University of Georgia, Plant Biology, 2502 Miller Plant Sciences, Athens, GA, 30602, United States
2 - University Of Georgia, Plant Biology, 2502 Miller Plant Sciences, Athens, GA, 30602, USA

Keywords:
sweet potato
Ipomoea
Root Anatomy
morning glory.

Presentation Type: Recent Topics Poster
Session: P
Location: /
Date: Monday, July 28th, 2014
Time: 5:30 PM
Number: PRT003
Abstract ID:1240
Candidate for Awards:None