Exploring the limits for reduction of plastid genomes: a case study of the mycoheterotrophic orchids Epipogium aphyllum and Epipogium roseum.

ABSTRACT: The question on the patterns and limits of reduction of plastid genomes in nonphotosynthetic plants and the reasons of their conservation is one of the intriguing topics in plant genome evolution. Here, we report sequencing and analysis of plastid genome in nonphotosynthetic orchids Epipogium aphyllum and Epipogium roseum, which, with sizes of 31 and 19 kbp, respectively, represent the smallest plastid genomes characterized by now. Besides drastic reduction, which is expected, we found several unusual features of these "minimal" plastomes: Multiple rearrangements, highly biased nucleotide composition, and unprecedentedly high substitution rate. Only 27 and 29 genes remained intact in the plastomes of E. aphyllum and E. roseum-those encoding ribosomal components, transfer RNAs, and three ad

SUBMITTER: Schelkunov MI 

PROVIDER: S-EPMC4419786 | biostudies-literature | 2015 Jan

REPOSITORIES: biostudies-literature