The complete chloroplast genome sequence of Sargassum fusiforme is presented here. Circular mapping revealed that the complete chloroplast DNA sequence of S. fusiforme was 124,298 bp in length and had an overall AT content of 69.57%, including 137 protein-coding genes, 2 open reading frames, 28 transfer RNA genes, and 6 ribosomal RNA genes. The phylogenetic tree based on Bayesian shows that all kinds of Phaeophyceae were clustered into two monophyletic groups.
Sargassum fusiforme is an important economic seaweed in East Asia. In this study, we characterized the complete chloroplast genome sequence of S. fusiforme using PacBio long-read sequencing technology. It had a circular mapping molecular with the length of 124,286 bp, with a large single-copy region (LSC, 73,437 bp) and a small single copy region (SSC, 40,131 bp) separated by a pair of inverted repeats (IRs, 5,359 bp). The cp genome contained 173 genes including 139 protein-coding, 6 rRNA, and 28 tRNA genes. The phylogenomic analysis indicated that S. fusiforme is closely related to S. thunbergii.
To better understand the mechanism of inherent salt resistance in Jerusalem artichoke (Helianthus tuberosus L.), physiological and metabolic responses of tubers at the initiation stage of sprouting under different salt stress levels were evaluated in the present study. As a result, 28 metabolites were identified using proton nuclear magnetic resonance (1H-NMR) spectroscopy. Jerusalem artichoke tubers showed minor changes in metabolic response under moderate salt stress when they had not yet sprouted, where metabolism was downregulated at the start of sprouting and then upregulated significantly after plants became autotrophic. However, mild and severe salt stress levels caused different metabolic response patterns. In addition, the accumulation of fructose and sucrose was enhanced by moderate salt stress, while glucose was highly consumed. Aspartate and asparagine showed accelerated accumulation in sprouting Jerusalem artichoke tubers that became autotrophic, suggesting the enhancement of photosynthesis by moderate salt stress.
Aquatic agriculture in heavy-metal-polluted coastal areas faces major problems due to heavy metal transfer into aquatic organisms, leading to various unexpected changes in nutrition and primary and/or secondary metabolism. In the present study, the dual role of heavy metal copper (Cu) played in the metabolism of photosynthetic organism, the edible seaweed Sargassum fusiforme, was evaluated by characterization of biochemical and metabolic responses using both 1H NMR and GC-MS techniques under acute (47 µM, 1 day) and chronic stress (8 µM, 7 days). Consequently, photosynthesis may be seriously inhibited by acute Cu exposure, resulting in decreasing levels of carbohydrates, e.g., mannitol, the main products of photosynthesis. Ascorbate may play important roles in the antioxidant system, whose content was much more seriously decreased under acute than that under chronic Cu stress. Overall, these results showed differential toxicological responses on metabolite profiles of S. fusiforme subjected to acute and chronic Cu exposures that allowed assessment of impact of Cu on marine organisms.