Ecological and evolutionary significance of genomic GC content diversity in monocots

TLDR

A large-scale survey of genomic nucleotide composition across monocots enabled the first rigorous test of its biological significance in plants. The authors aim to develop a stratified sampling approach combined with a quantile regression‑like phylogenetic analysis to study GC content diversity. They applied this stratified sampling of distribution data and phylogenetic quantile regression to assess GC content across monocot genomes. They found that GC content correlates with genome size and holocentric chromosome structure, may have driven ecological shifts such as the rise of grass‑dominated biomes, and identified groups with unusually high or low GC content that warrant further study.

Abstract

Significance Our large-scale survey of genomic nucleotide composition across monocots has enabled the first rigorous testing, to our knowledge, of its biological significance in plants. We show that genomic DNA base composition (GC content) is significantly associated with genome size and holocentric chromosomal structure. GC content may also have deep ecological relevance, because changes in GC content may have played a significant role in the evolution of Earth’s biota, especially the rise of grass-dominated biomes during the mid-Tertiary. The discovery of several groups with very unusual GC contents highlights the need for in-depth analysis to uncover the full extent of genomic diversity. Furthermore, our stratified sampling method of distribution data and quantile regression-like logic of phylogenetic analyses may find wider applications in the analysis of spatially heterogeneous data.