The complete mitochondrial genome of Cycas debaoensis revealed unexpected static evolution in gymnosperm species
A recent research entitled ‘The complete mitochondrial genome of Cycas debaoensis revealed unexpected static evolution in gymnosperm species’ had been reported in PLoS One on 22th July 2021.
Gymnosperms, with approximately 1,000 species, are considered as economically and ecologically significant plants as they account for roughly 40% of the world’s forests flora. Mitochondrial genomes of vascular plants are well known for their liability in architecture evolution. However, the evolutionary features of mitogenomes at intra-generic level are seldom studied in vascular plants, especially among gymnosperms.
Habib et al. (Fairy Lake Botanical Garden, Shenzhen & CAS) assembled the mitochondrial genome of Cycas debaoensis (413,715 bp) and compared it with C. taitungensis, mt genome of representative gymnosperms, and other major land plant lineages. Mitogenomes of Cycas are highly conserved in both gene content and gene order. The stability of Cycas mt genomes and lack of recombinations is unexpected in the case of their highly repetitive mt genomes. These repeated sequences significantly contributed to the fairly large size of introns. This stability of Cycas mt genome is positively correlated to the expansion of three DSBR protein families in Cycas nuclear genome.
Fig. The mitogenome of Cycas debaoensis (A), RNA-editing events in C. debaoensis (B), and mitochondrial gene order rearrangements in major land plant groups (C).
The mitogenome of C. debaoensis allow us to understand structural dynamics of early seed plant mitogenomes and provides an opportunity for further comparative studies and enhance our understanding regarding stability of gymnosperm mitogenome at inter-species level by comparing it with the available mitogenomes of gymnosperms, and the factors affecting structural rearrangements and genetic basis underlying.
Dr. Sadaf Habib, a Pakistani post-doctoral fellow jointly supervised by Prof. Zhang Shouzhou of Fairy Lake Botanical Garden and Prof. Liao Wenbo of Sun Yat-sen University, is the first author. Prof. Zhang Shouzhou and Prof. Liao Wenbo are the co-corresponding authors. Prof. Liu Yang and Dr. Dong Shanshan from Fairy Lake Botanical Garden also participated in the work. The Cycad genome project was funded by the Biodiversity Survey and Assessment Project (No. 2019HJ2096001006) of the Ministry of Ecology and Environment, China, to Prof. Zhang Shouzhou.
