Pangenome-based trajectories of intracellular gene transfers in Poaceae unveil high cumulation in Triticeae

• DOI: 10.1093/plphys/kiad319
• Publication Date: 2023-05-30T09:39:38Z
• Authors: Yongming Chen; Yiwen Guo; Xiaoming Xie; Zihao Wang; Lingfeng Miao; Zhengzhao Yang; Yuannian Jiao; Chaojie Xie; Jie Liu; Zhaorong Hu; Mingming Xin; Yingyin Yao; Zhongfu Ni; Qixin Sun; Huiru Peng; Weilong Guo
• Keywords: 2. Zero hunger; Evolution, Molecular; Oryza; 15. Life on land; Poaceae; Zea mays; Triticum; Genome, Plant; Research Article

Abstract Intracellular gene transfers (IGTs) between the nucleus and organelles, including plastids and mitochondria, constantly reshape the nuclear genome during evolution. Despite the substantial contribution of IGTs to genome variation, the dynamic trajectories of IGTs at the pangenomic level remain elusive. Here, we developed an approach, IGTminer, that maps the evolutionary trajectories of IGTs using collinearity and gene reannotation across multiple genome assemblies. We applied IGTminer to create a nuclear organellar gene (NOG) map across 67 genomes covering 15 Poaceae species, including important crops. The resulting NOGs were verified by experiments and sequencing data sets. Our analysis revealed that most NOGs were recently transferred and lineage specific and that Triticeae species tended to have more NOGs than other Poaceae species. Wheat (Triticum aestivum) had a higher retention rate of NOGs than maize (Zea mays) and rice (Oryza sativa), and the retained NOGs were likely involved in photosynthesis and translation pathways. Large numbers of NOG clusters were aggregated in hexaploid wheat during 2 rounds of polyploidization, contributing to the genetic diversity among modern wheat accessions. We implemented an interactive web server to facilitate the exploration of NOGs in Poaceae. In summary, this study provides resources and insights into the roles of IGTs in shaping interspecies and intraspecies genome variation and driving plant genome evolution.