Abstract Detail

Evolutionary Developmental Biology (Evo-Devo)

Howarth, Dianella [1], Lee, Aaron [2], Rahman-Vyas, Hiba [3], Walker, Joseph [4], Donoghue, Michael [5], Smith, Stephen [6], Clement, Wendy [7].

Gene duplication and loss within the CUP-SHAPED COTYLEDON (CUC) family correlates with fusion in honeysuckles (Lonicera, Caprifoliaceae).

Diversification in plant form commonly arises from changes in fusion of various plant tissues. Genes that regulate organ fusion include members of the NAM clade of NAC transcription factors, especially CUC (CUP-SHAPED COTYLEDON), which have been shown to affect organ boundaries in leaves and floral organs. Honeysuckles (Lonicera, Caprifoliaceae) display a variety of fused and unfused floral, fruit, and leaf structures with many independent origins, providing a natural system to study the molecular and developmental evolution of organ fusion. To begin exploring organ fusion in Lonicera, we used molecular and computational approaches to recover CUC and related NAC genes in Lonicera and relatives. De novo assemblies were generated from seven Lonicera genome skimming libraries, five Lonicera floral transcriptome libraries, and six transcriptome libraries from other Dipscales species. Additionally, transcriptomes from public data repositories were utilized for four Dipsacales species. All of these data represented the phylogenetic breadth of the Dipsacales. Putative gene copies were recovered using BLAST, and gene trees combining new and published data were constructed to assess the evolution of CUC-like genes in Dipsacales. Phylogenetic analyses of these data supported the recovery of Dipsacales sequences from all six of the hypothesized angiosperm NAM clades (based on A. thaliana and O. sativa sequences). We found Dipsacales sequences in each of the two clades that have been shown to regulate fusion, CUC1/2 and CUC3. However, within the Caprifoliaceae, including Lonicera, our findings suggest that there has been a duplication of CUC1/2 and a potential genomic loss of CUC3. The loss of CUC3 is correlated with a marked increase in transitions in extrafloral fusion that occurs across the Caprifoliaceae. This appears to be the first reported case of the loss of this major angiosperm wide transcription factor in a plant lineage. We also discuss duplication patterns in other NAM genes, and possible broad expression patterns hypothesized from floral transcriptome data from all six of the NAM genes. Moving forward, we hope to study CUC gene evolution in the context of fusion morphology within the clade. This research demonstrates the utility of genome skimming in studying Lonicera gene evolution, and it highlights the potential for establishing Lonicera as a model lineage to study organ fusion.

1 - St. John's University, Department Of Biological Sciences, St. Albert Hall Rm 257, 8000 Utopia Pkwy, Jamiaca, NY, 11439, United States
2 - The College of New Jersey, Biology, 2000 Pennington Road, Ewing, NJ, 08628, USA
3 - The College of New Jersey, Biology, 2000 Pennington Rd., Ewing, NJ, 08628, USA
4 - University of Cambridge, Sainsbury Laboratory, UK
5 - Yale University, Department Of Ecology And Evolutionary Biology, Po Box 208106, New Haven, CT, 06511, United States
6 - University of Michigan, Department of Ecology and Evolutionary Biology, Ann Arbor, MI, 48103, USA
7 - The College Of New Jersery, Dept. Of Biology, 2000 Pennington Road, Ewing, NJ, 08628, United States

Keywords:
CUP-SHAPED COTYLEDON
CUC
NAM
Lonicera
Caprifoliaceae
Dipsacales
fusion.

Presentation Type: Oral Paper
Session: EVDV1, Evolutionary Developmental Biology (Evo-Devo)
Location: Tucson E/Starr Pass
Date: Monday, July 29th, 2019
Time: 4:30 PM
Number: EVDV1012
Abstract ID:809
Candidate for Awards:None