Most plant species can form symbioses with arbuscular mycorrhizal fungi (AMFs), which may enhance the host plant’s acquisition of soil nutrients. In contrast to phosphorus nutrition, the molecular mechanism of mycorrhizal nitrogen (N) uptake remains largely unknown, and its physiological relevance is unclear. Here, we identified a gene encoding an AMF-inducible ammonium transporter, ZmAMT3;1, in maize (Zea mays) roots. ZmAMT3;1 was specifically expressed in arbuscule-containing cortical cells and the encoded protein was localized at the peri-arbuscular membrane. Functional analysis in yeast and Xenopus oocytes indicated that ZmAMT3;1 mediated high-affinity ammonium transport, with the substrate $NH4+$ being accessed, but likely translocating uncharged NH₃. Phosphorylation of ZmAMT3;1 at the C-terminus suppressed transport activity. Using ZmAMT3;1-RNAi transgenic maize lines grown in compartmented pot experiments, we demonstrated that substantial quantities of N were transferred from AMF to plants, and 68%–74% of this capacity was conferred by ZmAMT3;1. Under field conditions, the ZmAMT3;1-dependent mycorrhizal N pathway contributed >30% of postsilking N uptake. Furthermore, AMFs downregulated ZmAMT1;1a and ZmAMT1;3 protein abundance and transport activities expressed in the root epidermis, suggesting a trade-off between mycorrhizal and direct root N-uptake pathways. Taken together, our results provide a comprehensive understanding of mycorrhiza-dependent N uptake in maize and present a promising approach to improve N-acquisition efficiency via plant–microbe interactions.

Metabolic syndrome is the pathological basis of cardiovascular and cerebrovascular diseases and type 2 diabetes. With the prevalence of modern lifestyles, the incidence of metabolic syndrome has risen rapidly. In recent years, marine sulfate polysaccharides (MSPs) have shown positive effects in the prevention and treatment of metabolic syndrome, and they mainly come from seaweeds and marine animals. MSPs are rich in sulfate and have stronger biological activity compared with terrestrial polysaccharides. MSPs can alleviate metabolic syndrome by regulating glucose metabolism and lipid metabolism. In addition, MSPs prevent and treat metabolic syndrome by interacting with gut microbiota. MSPs can be degraded by gut microbes to produce metabolites such as short chain fatty acids (SCFAs) and free sulfate and affect the composition of gut microbiota. The difference between MSPs and other polysaccharides lies in the sulfation pattern and sulfate content, therefore, which is very important for anti-metabolic syndrome activity of MSPs. This review summarizes the latest findings on effects of MSPs on metabolic syndrome, mechanisms of MSPs in treatment/prevention of metabolic syndrome, interactions between MSPs and gut microbiota, and the role of sulfate group and sulfation pattern in MSPs activity. However, more clinical trials are needed to confirm the potential preventive and therapeutic effects on human body. It may be a better choice to develop new functional foods containing MSPs for dietary intervention in metabolic syndrome.

The effect of commercial processing methods on the nutritional value of ready‐to‐eat (RTE) sea cucumber Apostichopus japonicas was examined in this study. RTE sea cucumber products named RTE‐T and RTE‐V were prepared by two commercial methods, traditional processing, and vacuum cooking, respectively. Proximate, polysaccharide and mineral element composition, amino acid profiles, and true retention values of RTE sea cucumber products were evaluated and compared. Both commercial processing methods significantly changed the nutrient composition in RTE products, except that of Zn and Cu. Comparison of true retention values among RTE products showed that novel commercial method of vacuum cooking resulted in lower nutrient loss and had a shorter processing time than traditional processing. However, soaking after vacuum cooking significantly increased the nutrient loss of RTE sea cucumber. Therefore, vacuum cooking without soaking may be a promising alternative for producing RTE sea cucumber products with high nutritional quality.

The sea cucumber (Apostichopus japonicus) is a high-priced and appreciated food. Output of cultured sea cucumber has been increasing in China. From a nutritional point of view, there is still limited data on the chemical composition of cultured sea cucumber from pond and cage aquaculture. Therefore, the nutritional value of sea cucumber from 4 important aquaculture regions of Dalian, Yantai, Qingdao, and Putai in China were evaluated in the present work. The proximate composition, except for protein, and the profiles of amino acid and fatty acid were significantly different among the aquaculture regions, especially, saturated fatty acids (SFA), monounsaturated fatty acids (MUFA), and polyunsaturated fatty acids (PUFA). The cultured sea cucumbers were rich in glutamine (66.90–71.60 g kg⁻¹), glycine (54.30–58.90 g kg⁻¹), and leucine (29.20–32.40 g kg⁻¹) and showed a high content in PUFA (35.26%–46.47%), especially eicosapentaenoic (EPA, 10.04%–16.04%). All cultured sea cucumber have the recommended essential amino acid/total amino acid (0.33–0.35), lysine/arginine (0.66–0.74), and n-6/n-3 ratio (0.52–1.88) for good health status of humans and very low level of atherogenic and thrombogenic indices (0.20–0.36 and 0.21–0.29, respectively). The results indicate that the cultured sea cucumber has a nutritional value perfectly compatible with nutritious and healthy diets

Aquatic products are gaining popularity due to their delicacy and high nutrient value. However, they are perishable, with a short shelf-life. Frozen storage is associated with adverse effects, leading to protein oxidation and degradation, thereby altering the protein’s structural integrity and subsequently influencing the palatability of protein-based food products. To address these challenges, novel antifreeze peptides have gained significant attention. Antifreeze peptides are a class of small molecular weight proteins or protein hydrolysates that offer protection to organisms in frozen or sub-frozen environments. They offer distinct advantages over conventional commercial antifreeze agents and natural antifreeze proteins. This review provides an overview of the current state of research on antifreeze agents, elucidates their characteristics and mechanisms, and examines their applications in aquatic products. Furthermore, the article offers insights into the prospective development and application prospects of antifreeze peptides.

Polysaccharide from marine shellfish has various bioactivities. In this study, the effects of polysaccharide from Patinopecten yessoensis skirt (PS) on boosting immune response in mice were evaluated, and the potential mechanisms were explored. The results showed that PS administration effectively increased the serum IgG and IgM levels, implying that PS had immune response-boosting properties. Moreover, PS administration could modulate the composition of the gut microbiota, and significantly improve short-chain fatty acids (SCFAs) metabolism, especially butyrate metabolism. Of note, the expression of the Tlr2, Tlr7, MyD88, Tnfa, and Il1b genes in toll-like receptor (TLR) signaling pathway was significantly increased. In summary, PS could boost immune response by modulating the gut microbiota and SCFAs metabolism correlating with the activation of the TLR signaling pathway. Therefore, PS can be developed as a special ingredient for functional product.