Loss of mitogenome-encoded respiratory genes complemented by nuclear transcripts in halophyte Pandanus odorifer (Forssk.) Kuntze

The mitochondrial genomes possess genes of five complexes involved in respiration. Mitochondrial gene content greatly varies across eukaryotes. Frequent gene losses have been reported in the mitogenomes of halophytes. In this study, we report, assemble, and annotate complete mitochondrial genome of a halophyte Pandanus odorifer (Forssk.) Kuntze (Pandanaceae). It is a commercially important species for its essential oil. It grows naturally in coastal regions and can withstand winds as well as salt sprays. The mitogenome of P. odorifer is circular with length of 330,962 bp. The genome contains 33 protein coding genes, 3 rRNAs, and 6 tRNAs. The analysis revealed that the important respiratory genes ccmC, cox1, nad1, nad4, and nad9 were pseudogenized in mitogenome but nuclear encoded copies of cox1, nad1, and nad9 were recovered. The phylogenetic analysis placed P. odorifer sister to P. tectorius. Further, mitogenome was compared with the other monocot mitogenomes for their gene contents. Thus, the study provides first complete mitochondrial genome for the family Pandanaceae and order Pandanales.