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Title: The chicken or the egg? Plastome evolution and an independent loss of the inverted repeat in papilionoid legumes
Summary

The plastid genome (plastome), while surprisingly constant in gene order and content across most photosynthetic angiosperms, exhibits variability in several unrelated lineages. During the diversification history of the legume family Fabaceae, plastomes have undergone many rearrangements, including inversions, expansion, contraction and loss of the typical inverted repeat (IR), gene loss and repeat accumulation in both shared and independent events. While legume plastomes have been the subject of study for some time, most work has focused on agricultural species in the IR‐lacking clade (IRLC) and the plant modelMedicago truncatula. The subfamily Papilionoideae, which contains virtually all of the agricultural legume species, also comprises most of the plastome variation detected thus far in the family. In this study three non‐papilioniods were included among 34 newly sequenced legume plastomes, along with 33 publicly available sequences, to assess plastome structural evolution in the subfamily. In an effort to examine plastome variation across the subfamily, approximately 20% of the sampling represents the IRLC with the remainder selected to represent the early‐branching papilionoid clades. A number of IR‐related and repeat‐mediated changes were identified and examined in a phylogenetic context. Recombination between direct repeats associated withycf2resulted in intraindividual plastome heteroplasmy. Although loss of the IR has not been reported in legumes outside of the IRLC, one genistoid taxon was found to completely lack the typical plastome IR. The role of the IR and non‐IR repeats in the progression of plastome change is discussed.

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Award ID(s):
1853024
NSF-PAR ID:
10449648
Author(s) / Creator(s):
 ;  ;  ;  ;  ;  ;  ;  
Publisher / Repository:
Wiley-Blackwell
Date Published:
Journal Name:
The Plant Journal
Volume:
107
Issue:
3
ISSN:
0960-7412
Page Range / eLocation ID:
p. 861-875
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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