Assembly and analysis of first genomes of chloroplast and mitochondria of seashore paspalum and the gene transfer among the organelles and nucleus

Background Mitochondria and chloroplast are intracellular organelles that generate energy for the cells in plants. Seashore paspalum ( Paspalum vaginatum Sw.), a halophytic, warm-season grass, has excellent tolerance capacity towards abiotic stress and is related to various grain crops. The nuclei genome of P. vaginatum has been reported recently, while information on the chloroplast and mitochondrial genomes of P. vaginatum is unavailable so far. Results The genomes of cytoplasmic organelles (mitochondria and chloroplast) of a warm-season turfgrass with superior salt tolerance ( Paspalum vaginatum ) were sequenced and assembled. The 504,515-bp and 140,483-bp genome maps of mitochondria and chloroplast contains a detailed list of protein-coding genes (PCGs), rRNAs and tRNAs. The mitochondrial genome contains large number of small and large repeats, and has little sequence similarity with its relatives such as maize and sorghum. The 580 and 432 RNA editing sites were predicted on 41 PCGs of mitochondrial genome. In the P. vaginatum mitochondrial genome, 185 sequence fragments of nuclear sequences were found, accounting for 16.95% of the total length. 7 chloroplast-derived genes had the 100% similarity with 6 mitochondrial PCGs. Transcriptomic changes in a few PCGs targeted to the two organelles were revealed during salt stress. Conclusions This study provides a better understanding of knowledge on plant mitochondrial and chloroplast genomes in seashore paspalum.