Abstract Detail

Systematics

Chalopin, Domitille [1], Clark, Lynn [2], Wysocki, William [3], Duvall, Mel [4], Bennetzen, Jeffrey [5].

The use of transposable elements as fingerprint tools to resolve the hybrid origin of the bamboo lineage.

The bamboos (Bambusoideae, Poaceae) constitute the third most diverse subfamily of grasses and represent the only major grass lineage to diversify primarily in association with forests. About 1700 described species have been classified into three main tribes, Olyreae (herbaceous bamboos), Bambuseae (tropical woody bamboos) and Arundinarieae (temperate woody bamboos). While nuclear gene analyses were consistent with a common origin of the woody tribes, plastome phylogenomic analyses strongly suggested paraphyly of the woody bamboos, with Bambuseae sister to Olyreae. The objective of the current study was to clarify the origin and history of the three bamboo tribes. We collected 53 species of bamboos spread across the different tribes and generated low-depth sample sequence data, from which plastid genomes were assembled and nuclear repeats (interspersed elements and simple repeats) were analyzed. For the first time within the bamboos, we analyzed both plastid and nuclear genomes in the same study and using the same species. We infer a hybridization event between an Olyreae ancestor and woody ancestor A that gave rise to the allotetraploid Bambuseae, with capture of the Olyreae plastome and subsequent dominance of the Olyreae nuclear genome in the Neotropical woody bamboos. We also infer a second hybridization event between woody ancestors A and B that gave rise to the Arundinarieae with retention of that plastome. The Paleotropical Bambuseae arose from either a third hybridization event (between woody A and the Olyreae ancestor, with capture of the Olyreae plastome but dominance of the woody A nuclear genome) or splitting of the ancestral allotetraploid Bambuseae, but with dominance of the woody A nuclear genome in this lineage. A third nuclear genome was incorporated into the Paleotropical Bambuseae lineage prior to its major diversification, but this history remains ambiguous. As a complement to plastome and nuclear genes, which are usually used to establish species relationships, we also demonstrated that facile transposable element analysis can provide a powerful fingerprint tool to establish lineage origin and history.

1 - Universite de Lyon, Laboratoire de Biologie et Modélisation de la Cellule, ENS de Lyon, CNRS UMR 5239, INSERM U1210, 15 parvis Descartes, Lyon, France
2 - Iowa State University, Department Of Ecology, Evolution, And Organismal Biology, 251 Bessey Hall, 2200 Osborn Dr., Ames, IA, 50011, United States
3 - University of Chicago, Center for Data Intensive Sciences, Chicago, IL, USA
4 - Northern Illinois University, Plant Molecular And Bioinformatics Center And Department Of Biology, 1425 W Lincoln Hwy, Dekalb, IL, 60115, United States
5 - University of Georgia, Department of Genetics, 120 Green Street, Athens, GA, 30602-7223, USA

Keywords:
Bambusoideae
bamboo evolution
transposable elements
ancient hybridization
allopolyploidy.

Presentation Type: Oral Paper
Session: SYS1, Systematics I: Land plants, Gymnosperms to Rosids part 1
Location: Tucson H/Starr Pass
Date: Monday, July 29th, 2019
Time: 3:00 PM
Number: SYS1007
Abstract ID:854
Candidate for Awards:None