A census of nuclear cyanobacterial recruits in the plant kingdom

PLoS One. 2015 Mar 20;10(3):e0120527. doi: 10.1371/journal.pone.0120527. eCollection 2015.

Abstract

The plastids and mitochondria of the eukaryotic cell are of endosymbiotic origin. These events occurred ~2 billion years ago and produced significant changes in the genomes of the host and the endosymbiont. Previous studies demonstrated that the invasion of land affected plastids and mitochondria differently and that the paths of mitochondrial integration differed between animals and plants. Other studies examined the reasons why a set of proteins remained encoded in the organelles and were not transferred to the nuclear genome. However, our understanding of the functional relations of the transferred genes is insufficient. In this paper, we report a high-throughput phylogenetic analysis to identify genes of cyanobacterial origin for plants of different levels of complexity: Arabidopsis thaliana, Chlamydomonas reinhardtii, Physcomitrella patens, Populus trichocarpa, Selaginella moellendorffii, Sorghum bicolor, Oryza sativa, and Ostreococcus tauri. Thus, a census of cyanobacterial gene recruits and a study of their function are presented to better understand the functional aspects of plastid symbiogenesis. From algae to angiosperms, the GO terms demonstrated a gradual expansion over functionally related genes in the nuclear genome, beginning with genes related to thylakoids and photosynthesis, followed by genes involved in metabolism, and finally with regulation-related genes, primarily in angiosperms. The results demonstrate that DNA is supplied to the nuclear genome on a permanent basis with no regard to function, and only what is needed is kept, which thereby expands on the GO space along the related genes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cyanobacteria / classification
  • Cyanobacteria / genetics*
  • Gene Transfer, Horizontal
  • Genetic Variation
  • Genome
  • Genome, Mitochondrial
  • Genome, Plastid
  • Plants / genetics*
  • Plastids / genetics
  • Symbiosis*

Grants and funding

This work was supported by the grants from the National Science and Technology Major Project of China (2013ZX08002004-007; 2014ZX08010004-004), the International Collaboration Project of the Chinese Ministry of Science and Technology, and the Innovative Foundation of Huazhong University of Science and Technology (2014QN124). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.