Organellar genomes of the putative Hawaiian endemic species Gibsmithia punonomaewa (Gigartinales, Rhodophyta): First available genomes for the Dumontiaceae

We have reported the first mitochondrial (GenBank accession PV035080) and chloroplast (GenBank accession PV035081) genomes for a representative of the gigartinalean family Dumontiaceae (Gibsmithia punonomaewa). High-throughput sequencing yielded both organellar genomes for the holotype specimen of Gibsmithia punonomaewa, a recently described species that is also a putative endemic to the mesophotic zone of the Hawaiian Islands. Gene content and order of the 26,428-bp mitochondrial genome are conserved relative to other available genomes of the Gigartinales. The genome contains 52 genes, including 25 protein-coding sequences (CDSs), 3 rRNAs, and 24 tRNAs, as well as one group II intron in a trnI-GAU tRNA. The chloroplast genome is 185,316 bp in length and contains 236 genes, including 203 CDSs, three rRNAs, and 30 tRNAs, and one group II intron in a trnM-CAU tRNA. Both organellar genomes displayed high synteny compared to close relatives in the order Gigartinales, with unique features restricted to several open reading frames. Phylogenomic analyses of the mitochondrial and chloroplast genomes with other gigartinalean representatives yielded well-resolved phylogenies that supported an early diverging position of the Dumontiaceae within the order Gigartinales.