Project description:This study provides a first large-scale cloning and characterization of Porphyra miRNAs and their predicted targets. These miRNAs belong to 224 conserved miRNA families and 7 are novel in Porphyra. These miRNAs add to the growing database of new miRNA and lay the foundation for further understanding of miRNA function in the regulation of Porphyra yezoensis development.
Project description:This study provides a first large-scale cloning and characterization of Porphyra miRNAs and their predicted targets. These miRNAs belong to 224 conserved miRNA families and 7 are novel in Porphyra. These miRNAs add to the growing database of new miRNA and lay the foundation for further understanding of miRNA function in the regulation of Porphyra yezoensis development. We constructed a small RNA library from Porphyra yezoensis.
Project description:Porphyra is a macrophytic red alga of the Bangiales that is important ecologically and economically. We describe the genomes of three bacteria in the phylum Planctomycetes (designated P1, P2 and P3) that were isolated from blades of Porphyra umbilicalis (P.um.1). These three Operational Taxonomic Units (OTUs) belong to distinct genera; P2 belongs to the genus Rhodopirellula, while P1 and P3 represent undescribed genera within the Planctomycetes. Comparative analyses of the P1, P2 and P3 genomes show large expansions of distinct gene families, which can be widespread throughout the Planctomycetes (e.g., protein kinases, sensors/response regulators) and may relate to specific habitat (e.g., sulfatase gene expansions in marine Planctomycetes) or phylogenetic position. Notably, there are major differences among the Planctomycetes in the numbers and sub-functional diversity of enzymes (e.g., sulfatases, glycoside hydrolases, polysaccharide lyases) that allow these bacteria to access a range of sulfated polysaccharides in macroalgal cell walls. These differences suggest that the microbes have varied capacities for feeding on fixed carbon in the cell walls of P.um.1 and other macrophytic algae, although the activities among the various bacteria might be functionally complementary in situ. Additionally, phylogenetic analyses indicate augmentation of gene functions through expansions arising from gene duplications and horizontal gene transfers; examples include genes involved in cell wall degradation (e.g., κ-carrageenase, alginate lyase, fucosidase) and stress responses (e.g., efflux pump, amino acid transporter). Finally P1 and P2 contain various genes encoding selenoproteins, many of which are enzymes that ameliorate the impact of environmental stresses that occur in the intertidal habitat.
Project description:Porphyra/Pyropia seaweeds are promising sources for functional foods development, offering a rich macro- and micronutrient profiles. In New Zealand (NZ), endemic Porphyra/Pyropia species (karengo), exhibit considerable variability driven by geography, seasonality, and climate, which may influence their nutritional quality. Despite their use as traditional foods, the NZ Porphyra/Pyropia remain underutilized commercially, in part due to the lack of biomolecular characterisation, particularly their bioactive protein components, hindering evidence-based species selection for seaweed farming commercialisation and functional food development. This study presents the first proteomic characterization of three NZ Porphyra/Pyropia species: Pyropia virididentata, Pyropia cinnamomea, and Porphyra GRB complex. Mass spectrometry-based proteomics analysis identified differences in the phycobiliprotein composition among the species, with the Porphyra GRB complex containing higher levels of phycocyanin. Using the protein sequence information, in silico gastrointestinal digestion analysis predicted that phycobiliproteins from NZ Porphyra/Pyropia seaweeds can potentially release bioactive peptides capable of inhibiting angiotensin-converting enzyme (ACE) and dipeptidyl peptidase-IV (DPP-IV) activities. Sequence-based allergenicity prediction indicated possible cross-reactivity between NZ Porphyra/Pyropia β-phycoerythrin and β-phycocyanin against the β-phycocyanin allergen from spirulina, which is associated with a low incidence of allergy. Proximate analysis revealed that NZ Porphyra/Pyropia seaweeds have high protein (26–30.2 %) and carbohydrate (48.3–50.9 %) contents, and low fat and free sugar levels. Amino acid profiling further showed that NZ Porphyra/Pyropia seaweeds are relatively rich in sulphur-containing amino acids and umami-associated amino acids. Overall, these findings highlight the potential of NZ Porphyra/Pyropia seaweeds as a novel plant-based protein source for functional food applications.