Comparative Analysis of Sequence Polymorphism in Complete Organelle Genomes of the ‘Golden Tide’ Seaweed Sargassum horneri between Korean and Chinese Forms

Abstract

Drifting and inundating brown seaweed Sargassum horneri biomass is called “golden tide”, as it resembles golden massive algal blooms like green tides. This phenomenon occurs globally and its serious ecological impacts on coastal ecosystems have recently begun to be paid attention to. In the present study, by sequencing whole organelle genomes of Korean indigenous S. horneri, we aimed to develop novel molecular markers that can be used for differentiating indigenous from nonindigenous individuals. To this end, we analyzed sequence polymorphisms in mitochondrial (mt) and chloroplast (cp) genomes of two Korean benthic samples in comparison to Chinese ones as a reference. We mapped mt genomes of 34,620~34,628 bp and cp genomes of 123,982~124,053 bp for the Korean samples. In comparative analyses, mtDNA cytochrome c oxidase subunit II (cox2) gene showed the highest number of single nucleotide polymorphisms (SNPs) between Korean and Chinese individuals. NADH dehydrogenase subunit 7 (Nad7)-proline tRNA (trnP) intergenic spacer (IGS) in the mt genome showed a 14 bp insertion or deletion (indel) mutation. For the cp genome, we found a total of 54 SNPs, but its overall evolution rate was approximately four-fold lower than the mt genome. Interestingly, analysis of Ka/Ks ratio in the cp genome revealed a signature of positive selection on several genes, although only negative selection prevalent in mt genome. The ‘candidate’ genetic markers that we found can be applied to discriminate between Korean indigenous and nonindigenous individuals. This study will assist in developing a molecular-based early detection method for effectively managing nonindigenous S. horneri in Korean waters.

Immune-Enhancing Effects of Marine Algae Extracts: Modulation of Macrophage Activation by Sargassum horneri, Sargassum fusiforme, and Undaria pinnatifida

“…Sargassum horneri has also been recognized as an environmental pollutant, particularly on Jeju Island, Korea [55]. Fish farms were found to be polluted with it, and an unpleasant odor on the beaches could be observed owing to its presence [56], which is regarded as an economic burden [57]. Thus, the Korean government and researchers are constantly contributing to efforts to use these materials as beneficial materials [58,59].…”

Review and Perspectives of the Use of Alginate as a Polymer Matrix for Microorganisms Applied in Agro-Industry

“…As mentioned above, alginate can be obtained from numerous brown algae. A large amount of biomass of the brown alga Sargassum horneri, known as "golden tide" has recently caused a severe ecological impact on coastal ecosystems in many countries [134]. Massive algal blooms are a menace to the economy and tourist attractions of affected countries.…”

Effects of extraction methods for a new source of biostimulant from Sargassum horneri on the growth of economically important red algae, Neopyropia yezoensis

“…What to do with all the excess biomass of this species is major problem in the region. S. horneri has not been studied as a source of biostimulants, but other Sargassum species have been suggested as a potential source for biostimulants applicable to farming 19 , 20 . Namely, lentils ( Lens esculenta ) exposed to Sargassum vulgare extract (5%), showed an improvement in growth 21 .…”