Fig. 2.

Plastome expression profiles of three representative Cymbidium species. The expression levels of one mycoheterotrophic (C. macrorhizon), one terrestrial (C. ensifolium), and one epiphytic (C. mannii) orchid plastome are shown. All of these representative species exhibited extensive ndh gene pseudogenization and/or loss events and with similar high-level expression profiles. Read coverages (with a cutoff of 100000) for each genomic site are plotted along each chromosome. Pseudogenized ndh genes are highlighted with asterisks and the ancestral locations of lost ndh genes are marked with arrows.