Complete Mitogenomes of Two Aragoa Species and Phylogeny of Plantagineae (Plantaginaceae, Lamiales) Using Mitochondrial Genes and the Nuclear Ribosomal RNA Repeat.

Jeffrey P Mower,Kirsten Wolff,Natalia Pabón-Mora,Lilly Hanley,Favio González

doi:10.3390/plants10122673

Abstract

Aragoa, comprising 19 high-altitude North Andean species, is one of three genera in the Plantagineae (Plantaginaceae, Lamiales), along with Littorella and Plantago. Based primarily on plastid data and nuclear ITS, Aragoa is sister to a clade of Littorella + Plantago, but Plantagineae relationships have yet to be assessed using multigene datasets from the nuclear and mitochondrial genomes. Here, complete mitogenomes were assembled for two species of Aragoa (A. abietina and A. cleefii). The mitogenomes of both species have a typical suite of genes for 34 proteins, 17 tRNAs, and three rRNAs. The A. abietina mitogenome assembled into a simple circular map, with no large repeats capable of producing alternative isoforms. The A. cleefii mitogenomic map was more complex, involving two circular maps bridged by a substoichiometric linear fragment. Phylogenetics of three mitochondrial genes or the nuclear rRNA repeat placed Aragoa as sister to Littorella + Plantago, consistent with previous studies. However, P. nubicola, the sole representative of subg. Bougueria, was nested within subg. Psyllium based on the mitochondrial and nuclear data, conflicting with plastid-based analyses. Phylogenetics of the nuclear rRNA repeat provided better resolution overall, whereas relationships from mitochondrial data were hindered by extensive substitution rate variation among lineages.

Highlights

Aragoa is a genus of 19 woody shrubs that reside at high altitudes in the páramos of the Northern Andes of Colombia and Venezuela [1,2,3]
We performed an analysis of the nuclear ribosomal RNA cluster, which includes genes for 18S, 5.8S, and 26S rRNAs separated by ITS1 and ITS2 regions
We describe the complete mitogenomes of two Aragoa species and compare the phylogenetic signal for Plantagineae relationships using mitochondrial and nuclear loci with previous plastid phylogenomic results

Summary

Introduction

Aragoa is a genus of 19 woody shrubs that reside at high altitudes in the páramos of the Northern Andes of Colombia and Venezuela [1,2,3]. We performed an analysis of the nuclear ribosomal RNA (rRNA) cluster, which includes genes for 18S, 5.8S, and 26S rRNAs separated by ITS1 and ITS2 regions This dataset combined available data from GenBank with extracted nuclear rRNA sequences present in previous assemblies used to capture the plastid genome [8] and from the assemblies performed in this study. Using these data, we describe the complete mitogenomes of two Aragoa species and compare the phylogenetic signal for Plantagineae relationships using mitochondrial and nuclear loci with previous plastid phylogenomic results

Methods

Results

Conclusion