Dissecting mitogenomic conflict to illuminate angiosperm deep phylogeny: Sequence and architectural evidence
Liyun Nie, Jie Wang, Lei Huang, Jiali Kong, Bao Nie, Luke R. Tembrock, Shanshan Dong, Ravi Tiwari, Hui Wang, Shenglong Kan, Xinhui Zou, Zhiqiang Wu
Abstract
Deep relationships in the angiosperm tree of life remain highly controversial. To address this, we first assembled the complete mitochondrial genomes for Ceratophyllum demersum and Chloranthus sessilifolius , confirming a well-supported sister relationship that starkly conflicts with nuclear and plastid data. To dissect this classic cyto-nuclear conflict, we developed the ‘PhyloForensics’ framework, a novel diagnostic approach to systematically identify sources of phylogenetic instability. This framework revealed that signal heterogeneity (topological entropy variance) and information content (the proportion of informative sites) are the primary drivers of gene-tree conflict. Empirically validating this, we show that removing a small subset of “loudly conflicted” genes resolves deep-level incongruence, yielding a single, highly-supported topology previously obscured by noise. Finally, complementing this sequence-based resolution, we demonstrate that mitogenome architecture provides powerful phylogenetic signals, revealing predictable, mitogenome-wide evolutionary patterns, such as a significant negative correlation between branch length and both GC content and RNA editing sites. By integrating a validated conflict-resolution framework with architectural genomics, our study provides a comprehensive strategy for navigating the complexities of deep evolutionary histories. • The first complete mitogenomes for Ceratophyllum and Chloranthus establish a robust case study for cyto-nuclear conflict. • A novel diagnostic framework reveals signal heterogeneity, not evolutionary rate, as the primary driver of phylogenetic conflict. • Filtering a small subset of "loudly conflicted" genes resolves deep-level incongruence and reveals a single, highly-supported topology. • Mitogenome architecture provides a powerful, complementary source of non-sequence-based phylogenetic signal. • Mitogenome-wide evolutionary correlations are uncovered, linking substitution rates to GC content and RNA editing.