Ancient Horizontal Gene Transfers from Plastome to Mitogenome of a Nonphotosynthetic Orchid, Gastrodia pubilabiata (Epidendroideae, Orchidaceae)

Gastrodia pubilabiata is a nonphotosynthetic and mycoheterotrophic orchid belonging to subfamily Epidendroideae. Compared other typical angiosperm species, the plastome of G. dramatically reduced in size only 30,698 base pairs (bp). This reduction has led loss most photosynthesis-related genes some housekeeping plastome, which now contains 19 protein coding genes, three tRNAs, rRNAs. In contrast, species 79 30 four study decoded entire mitogenome pubilabiata, consisted 44 contigs with total length 867,349 bp. Its contained 38 nine The gene content similar plant mitogenomes even though twice as large ones. To determine possible transfer events between individual BLASTN searches were conducted, using all available sequences flowering sequences. Plastid rRNA fragments found at high frequency mitogenome. Seven plastid (ndhC, ndhJ, ndhK, psaA, psbF, rpoB, rps4) also identified pubilabiata. Phylogenetic trees these seven suggested that horizontal (HGT) from occurred before losses photosynthesis related leading lineage phylogeny orchid, it was estimated HGT might have approximately million years ago.