Tissues and industrial co-products formed during alginate extraction from <i>Laminaria hyperborea</i> provide different metabolite profiles depending on harvest season

The metabolic profiles of different tissues and industrially relevant co-products of alginate extraction from Laminaria hyperborea samples harvested in different seasons were assessed using Hydrophilic Interaction Liquid Chromatography – Mass Spectrometry (HILIC-MS). Positive and negative mode MS data, predicted exact mass data and matching with database and literature searches, allowed the putative identification of 57 major metabolites. The metabolites ranged from known and abundant components (e.g., iodide, mannitol, and various betaines) to components not previously noted in this species and 11 major components which could not be identified. The levels of these components varied between tissues and co-products with some metabolites seemingly specific to certain samples. The components also varied between winter and summer harvested material, perhaps reflecting seasonality in their biosynthesis and accumulation in the tissues and co-products. The approach applied in this work could assess when components of potential specific commercial interest were maximally accumulated and help plan the most efficient exploitation of the harvested biomass. It could also be used to define variation in components in L. hyperborea from different locations or potential biotopes of this species. This initial work extends our ability to understand the phenotype of seaweeds whilst also identifying new components and new commercial opportunities

An Integrated Assessment of the Horticulture Sector in Northern Australia to Inform Future Development

The horticulture sector in northern Australia, covering north of Western Australia (WA), Northern Territory (NT), and north Queensland (QLD), contributes $1.6 billion/year to the Australian economy by supplying diverse food commodities to meet domestic and international demand. To date, the Australian Government has funded several studies on developing the north’s agriculture sector, but these primarily focused on land and water resources and omitted an integrated, on-ground feasibility analysis for including farmers’/growers’ perspectives. This study is the first of its kind in the north for offering a detailed integrated assessment, highlighting farmers’ perspectives on the current state of the north’s horticulture sector, and related challenges and opportunities. For this, we applied a bottom-up approach to inform future agriculture development in the region, involving a detailed literature review and conducting several focus group workshops with growers and experts from government organisations, growers’ associations, and regional development agencies. We identified several key local issues pertaining to crop production, availability of, and secure access to, land and water resources, and workforce and marketing arrangements (i.e., transport or processing facilities, export opportunities, biosecurity protocols, and the role of the retailers/supermarkets) that affect the economic viability and future expansion of the sector across the region. For example, the availability of the workforce (skilled and general) has been a challenge across the north since the start of the COVID-19 pandemic in 2020. Similarly, long-distance travel for farm produce due to a lack of processing and export facilities in the north restricts future farm developments. Any major investment should be aligned with growers’ interests. This research highlights the importance of understanding and incorporating local growers’ and researchers’ perspectives, applying a bottom-up approach, when planning policies and programs for future development, especially for the horticulture sector in northern Australia and other similar regions across the globe where policy makers’ perspectives may differ from farmers

Flavonoid profiling and transcriptome analysis reveals new gene–metabolite correlations in tubers of Solanum tuberosum L.

Anthocyanin content of potato tubers is a trait that is attracting increasing attention as the potential nutritional benefits of this class of compound become apparent. However, our understanding of potato tuber anthocyanin accumulation is not complete. The aim of this study was to use a potato microarray to investigate gene expression patterns associated with the accumulation of purple tuber anthocyanins. The advanced potato selections, CO97216-3P/PW and CO97227-2P/PW, developed by conventional breeding procedures, produced tubers with incomplete expression of tuber flesh pigmentation. This feature permits sampling pigmented and non-pigmented tissues from the same tubers, in essence, isolating the factors responsible for pigmentation from confounding genetic, environmental, and developmental effects. An examination of the transcriptome, coupled with metabolite data from purple pigmented sectors and from non-pigmented sectors of the same tuber, was undertaken to identify these genes whose expression correlated with elevated or altered polyphenol composition. Combined with a similar study using eight other conventional cultivars and advanced selections with different pigmentation, it was possible to produce a refined list of only 27 genes that were consistently differentially expressed in purple tuber tissues compared with white. Within this list are several new candidate genes that are likely to impact on tuber anthocyanin accumulation, including a gene encoding a novel single domain MYB transcription factor

Metabolomic approach to identifying bioactive compounds in berries:advances toward fruit nutritional enhancement

Plant polyphenolics continue to be the focus of attention with regard to their putative impact on human health. An increasing and ageing human population means that the focus on nutrition and nutritional enhancement or optimisation of our foodstuffs is paramount. Using the raspberry as a model, we have shown how modern metabolic profiling approaches can be used to identify the changes in the level of beneficial polyphenolics in fruit breeding segregating populations and how the level of these components is determined by genetic and/or environmental control. Interestingly, the vitamin C content appeared to be significantly influenced by environment (growth conditions) whilst the content of the polyphenols such as cyanidin, pelargonidin and quercetin glycosides appeared much more tightly regulated, suggesting a rigorous genetic control. Preliminary metabolic profiling showed that the fruit polyphenolic profiles divided into two gross groups segregating on the basis of relative levels of cyanidin-3-sophoroside and cyanidin-3-rutinoside, compounds implicated as conferring human health benefits

Genetic and Environmental Effects on Tannin Composition in Strawberry (Fragaria × ananassa) Cultivars Grown in Different European Locations

Strawberry cultivars grown at different locations in Europe showed genotype- and environment-dependent variation in total phenol and anthocyanin contents. This study focused on the compositional diversity of tannins from these cultivars using a high-throughput liquid chromatography–mass spectrometric (LC-MS) technique. Cultivars grown in Germany showed differences in the relative amounts of proanthocyanidins (PACs) and ellagitannins (ETs). Cultivars grown at three different European locations showed differences in their PAC/ET balance. ‘Elsanta’ grown in Switzerland had higher levels of ET-derived than PAC-derived signals compared to ‘Elsanta’ grown in Germany and Denmark. The trend to increased ET-derived signals was also noted for ‘Clery’ grown in Switzerland over Germany and was apparent for ‘Korona’ grown in Denmark over Germany. The altered ET/PAC balance was confirmed by conventional LC-MS analysis, which highlighted specific changes in composition rather than a general increase in ET components. These findings are discussed with respect to the environmental conditions at the different European locations

IDENTIFICATION OF COMPONENTS IN KAZAKHSTAN HONEYS THAT CORRELATE WITH ANTIMICROBIAL ACTIVITY AGAINST WOUND AND SKIN INFECTING MICROORGANISMS

Background: Antimicrobial drug resistance is a major public health threat that can render infections including wound and skin infections untreatable. The discovery of new antimicrobials is critical. Approaches to discover novel antimicrobial therapies have included investigating the antimicrobial activity of natural sources such as honey. In this study, the anti-microbial activity and chemical composition of 12 honeys from Kazakhstan and medical grade manuka honey were investigated. Methods: Agar well diffusion and broth culture assays were used to determine anti-microbial activity against a range of skin and wound infecting micro-organisms. Folin-Ciocalteu method was used to determine the total phenol content of the honeys and non-targeted liquid chromatography analysis was performed to identify components that correlated with antimicrobial activity. Results: In the well diffusion assay, the most susceptible micro-organisms were a clinical isolate of Methicillin resistant Staphylococcus aureus (MRSA) and Enterococcus faecalis (ATCC 19433). Buckwheat & multi-floral honey from Kazakhstan demonstrated the highest antimicrobial activity against these two micro-organisms. Kazakhstan honeys with a buckwheat floral source, and manuka honey had the highest total phenol content. Non-targeted liquid chromatography analysis identified components that correlated with anti-microbial activity as hydroxyphenyl acetic acid, p-coumaric acid, (1H)–quinolinone, and abscisic acid. Conclusions: The Kazakhstan honeys selected in this study demonstrated antimicrobial activity against wound and skin infecting micro-organisms. Compounds identified as correlating with antimicrobial activity could be considered as potential bioactive agents for the treatment of wound and skin infections

A Transcript and Metabolite Atlas of Blackcurrant Fruit Development Highlights Hormonal Regulation and Reveals the Role of Key Transcription Factors

Blackcurrant fruit collected at six stages of development were assessed for changes in gene expression using custom whole transcriptome microarrays and for variation in metabolite content using a combination of liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry. Principal components analysis demonstrated that fruit development could be clearly defined according to their transcript or metabolite profiles. During early developmental stages, metabolite profiles were dominated by amino acids and tannins, whilst transcript profiles were enriched in functions associated with cell division, anatomical structure morphogenesis and cell wall metabolism. During mid fruit development, fatty acids accumulated and transcript profiles were consistent with seed and embryo development. At the later stages, sugars and anthocyanins accumulated consistent with transcript profiles that were associated with secondary metabolism. Transcript data also indicated active signaling during later stages of fruit development. A targeted analysis of signaling networks revealed a dynamic activation and repression of almost 60 different transcripts encoding transcription factors across the course of fruit development, many of which have been demonstrated as pivotal to controlling such processes in other species. Transcripts associated with cytokinin and gibberellin were highly abundant at early fruit development, whilst those associated with ABA and ethylene tended to be more abundant at later stages. The data presented here provides an insight into fruit development in blackcurrant and provides a foundation for further work in the elucidation of the genetic basis of fruit quality