Tef ( Eragrostis tef ) is an indigenous African cereal that is gaining global attention as a gluten-free “superfood” with high protein, mineral, and fibre contents. However, tef yields are limited by lodging and by losses during harvest owing to its small grain size (150× lighter than wheat). Breeders must also consider a strong cultural preference for white-grained over brown-grained varieties. Tef is relatively understudied with limited “omics” resources. Here, we resequence 220 tef accessions from an Ethiopian diversity collection and also perform multi-locational phenotyping for 25 agronomic and grain traits. Grain metabolome profiling reveals differential accumulation of fatty acids and flavonoids between white and brown grains. k -mer and SNP-based genome-wide association uncover important marker-trait associations, including a significant 70 kb peak for panicle morphology containing the tef orthologue of rice qSH1 —a transcription factor regulating inflorescence morphology in cereals. We also observe a previously unknown relationship between grain size, colour, and fatty acids. These traits are highly associated with retrotransposon insertions in homoeologues of TRANSPARENT TESTA 2 , a known regulator of grain colour. Our study provides valuable resources for tef research and breeding, facilitating the development of improved cultivars with desirable agronomic and nutritional properties.

To valorize sour jujube (Ziziphus acidojujuba) leaves, this work focused on the extraction, quantification, and bioactivity assessment of flavonoids. First, ultrasound-assisted extraction (UAE) was employed to extract total flavonoids from sour jujube leaves (SJL-TF), with the procedure optimized through single-factor design and response surface methodology (RSM). SJL-TF yield reached 48.47 +/- 0.36 mg/g under optimal circumstances, which included 61 % ethanol as extraction medium, an ultrasound power of 300 W, an extraction time of 33 min, and a liquid-solid ratio of 16 mL/g, showing higher extraction efficiency in comparison to the traditional Soxhlet extraction method. Scanning electron microscopy (SEM) analysis indicated that ultrasound treatment severely damaged the structural integrity of sour jujube leaves, which was more conducive to improving the SJL-TF yield. Then, polyamide resin chromatography was used to purify the crude SJL-TF extracts, increasing the SJL-TF purity by 3.2-fold to 74.58 +/- 0.63 %. By developing and validating a UPLC-QQQ-MS/MS method, ten main flavonoids in SJL-TF extracts, including catechin, rutin, isoquercetin, narirutin, nicotiflorin, quercitrin, phlorizin, luteolin, quercetin, and apigenin, were successfully detected concurrently for quality control purposes. Furthermore, the purified SJL-TF showed a strong ameliorative effect on dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) in mice, as evidenced by significant mitigation of colonic inflammation and pathological damage. Thus, this work will contribute to improving the application of sour jujube leaves, especially in the pharmaceutical sector.

Agricultural pathogens reduce annual crop yields by up to 40% and present a barrier to improving crop production to a level by which it will be able to support a global population of 9 billion by 2050. Current diagnostic methods are slow and lack specificity and typically rely on visual signs of infection, which appear late in the infection cycle. In this work, we explored whether the ambient ionization method rapid evaporative ionization mass spectrometry (REIMS) could be used to detect pathogen-specific biomarkers of infection against two important pathogens: the nematode Meloidogyne incognita and bacteria Pseudomonas syringae in the tomato plant (Solanum lycopersicum). Unlike previous implementations of REIMS for human clinical diagnostics, we explored the use of low-cost heating modalities in the form of a 450 nm laser and soldering iron (both below $200). After optimization, we found that the 450 nm laser provided the highest level of diagnostic classification accuracy and, importantly, could distinguish between infection causes with pathogen-specific biomarkers. This shows both the novel utility of REIMS for analysis of plant material, which would allow in situ and high-throughput analysis by the community for a broad range of plant metabolome applications, and also the potential of low-cost 450 nm lasers for use beyond this.

Metabolomics is one of the most widely used omics tools for deciphering the functional networks of the metabolites for crop improvement. However, it is technically demanding and costly. We propose a relatively inexpensive approach for metabolomics analysis in which metabolomics is combined with hyperspectral imaging via machine learning. This approach can be used to target important steps in flavonoid and lipid biosynthesis in rice. We extract 1848 hyperspectral indices and 887 metabolites from polished grains of 533 Oryza sativa accessions. Hyperspectral indices are then linked to metabolites through correlation analysis and modelling. Based on this, a total of 554 metabolites and 1313 hyperspectral indices are identified for further genome-wide association study (GWAS). By GWAS, we detect 17,509 significant locus-trait associations with 2882 single nucleotide polymorphisms (SNPs). Colocalization analysis links these SNPs to the corresponding metabolites and hyperspectral indices. We detect 6415 pairs of metabolites and hyperspectral indices within a linkage disequilibrium of 300 kb in the Oryza sativa genome. We then characterize 1761 candidate genes colocalized to these loci by transcriptomic analysis. We further verify novel candidate genes encoding a novel flavonoid (LOC_Os09g18450) and a flavonoid/lipid (LOC_Os07g11020) respectively by gene editing and overexpression in rice. Our findings indicate that hyperspectral imaging combined with machine learning methods could serve as a powerful tool for quickly and inexpensively assessing crop metabolites.

Chilling injury can limit the productivity of tomato (Solanum lycopersicum L.), especially in over-wintering greenhouse. We here explored the effect of the pre-application of chlorogenic acid (CGA) in mitigating the impact of chilling on tomato. Flowering plants subjected to either chilling (15 °C/5 °C, day/night) or pre-treatment with CGA followed by chilling for 6 days and then by a two-day control recovery period were compared to plants maintained at control conditions (25 °C/18 °C, day/night). Chilling significantly affected the expression of PSII CP43 Chlorophyll Apoprotein, NAD (P) H-Quinone Oxidoreductase Subunit 5 and ATP Synthase CF1 Beta Subunit, reduced leaf Fv/Fm and increased malondialdehyde (MDA) levels, suggesting elevated oxidative stress. These correlated with reduced shoot biomass. All these aspects were mitigated by pretreatment with CGA. Transcriptomic and metabolomic co-analysis indicated that CGA also suppressed the shikimate pathway, phenylpropanoid biosynthesis and phenylalanine accumulation but enhanced cinnamic acid and indole acetate synthesis. Hence, the pre-chilling CGA protected the tomato plant from chilling injury by maintaining light energy utilization and reprograming secondary metabolism. This study describes the mechanism through which CGA pre-treatment can be used to maintain tomato productivity under chilling conditions.

Nearly four decades have passed since fluorescence in situ hybridisation was first applied in plants to support molecular cytogenetic analyses across a wide range of species. Subsequent advances in DNA sequencing, bioinformatic analysis, and microscopy, together with the immunolocalisation of various nuclear components, have provided unprecedented insights into the cytomolecular organisation of the nuclear genome in both model and non-model plants, with crop species being perhaps the most significant. The ready availability of sequenced genomes is now facilitating the application of state-of-the-art cytomolecular techniques across diverse plant species. However, these same advances in genomics also pose a challenge to the future of plant molecular cytogenetics, as DNA sequence analysis is increasingly perceived as offering comparable insights into genome organisation. This perception persists despite the continued relevance of FISH-based approaches for the physical anchoring of genome assemblies to chromosomes. Furthermore, cytogenetic approaches cannot currently rival purely genomic methods in terms of throughput, standardisation, and automation. This review highlights the latest key topics in plant cytomolecular research, with particular emphasis on chromosome identification and karyotype evolution, chromatin and interphase nuclear organisation, chromosome structure, hybridisation and polyploidy, and cytogenetics-assisted crop improvement. In doing so, it underscores the distinctive contributions that cytogenetic techniques continue to offer in genomic research. Additionally, we critically assess future directions and emerging opportunities in the field, including those related to CRISPR/Cas-based live-cell imaging and chromosome engineering, as well as AI-assisted image analysis and karyotyping.

Pearl millet (Pennisetum glaucum) is a highly nutritious and climate resilient cereal cultivated on marginal lands in Asia and Africa underscoring its importance in global food security. Despite its nutritional value, the lipid and fatty acid variation and their genetic factors in pearl millet remain poorly understood. The Pearl Millet Inbred Germplasm Association Panel (PMiGAP), encompassing global diversity, provides a unique opportunity to explore these traits. This study investigated the variation in lipid and fatty acid composition within the PMiGAP population and applied GWAS to identify candidate genes. The total lipid content ranged from 3.93 % to 9.49 % with fourteen different fatty acids detected in this study. The linoleic acid and oleic acid were the most abundant fatty acids found in the PMiGAP. Palmitic acid varied from 4.35 % to 11.13 %, stearic acid from 0.12 % to 4.63 %, oleic acid from 7.33 % to 64.47 %, linoleic acid from 28.31 % to 85.51 %, and linolenic acid from 0.34 % to 1.69 %. Further, GWAS identified 64 significant marker-trait associations and 52 candidate genes within a 50 kb distance near these associations. The study provided novel insights on the genetic architecture of lipids and fatty acids, and a set of SNPs and candidate genes, which could be exploited in deriving pearl millet varieties through marker assisted breeding.

Bovine tuberculosis (bTB), caused by Mycobacterium bovis, is the most significant infectious disease of UK cattle. Badgers (Meles meles) can also be infected by M. bovis and may act as a source of infection for cattle. Management of infection risks could be supported by the availability of sensitive blood tests for bTB in badgers. We explored whether metabolomic changes in peripheral blood could be used for the diagnosis of bTB in wild, naturally infected badgers. Flow infusion electrospray - high-resolution mass spectrometry (FIE-HRMS) was used to assess the peripheral blood of trapped wild badgers (n = 148) for metabolite changes linked to bTB infection status. Infection status was established by culture, Dual Path Platform (DPP) and interferon (IFN-γ) blood tests or mycobacterial culture. Data were analysed by multivariate and receiver operating characteristic (ROC) curve analyses. Metabolite shifts were identified in badger blood samples associated with their corresponding infection status. Biochemical pathway analyses suggested that sphingolipid and glycerophospholipid metabolism was enriched in bTB badgers. However, some individual metabolites changes appeared to differ depending on badger sex. Our data shows that metabolomic assessment of peripheral blood can indicate bTB infection status. However, larger sample sizes are required to establish if our metabolites have potential as diagnostic biomarkers.

BACKGROUND:Early diagnosis of hypertension remains an important problem in cats. Lack of routine blood pressure screening in primary care practice, and the possibility of white coat artifact mean the discovery of a new diagnostic test, if less sensitive to short-term changes in blood pressure associated with veterinary care, would be useful. Identification of metabolomic changes in hypertensive cats could advance understanding of the pathogenesis of hypertension in cats, as well as identify novel biomarkers. OBJECTIVES:Use untargeted metabolomics to identify biochemical changes in cat plasma and urine between normotensive controls (NT) and hypertensive cats before treatment (HTpre); HTpre and hypertensive cats treated with amlodipine (HTtx). ANIMALS:Biobanked surplus plasma and urine samples were selected from client-owned cats (> 9 years old) that were NT (urine n = 17, plasma n = 19), HTpre (urine n = 13, plasma n = 19), or HTtx (urine n = 12, plasma n = 19). METHODS:Samples were profiled using flow infusion electrospray-high-resolution mass spectrometry, and differences assessed using univariate (paired or two sample t-tests) and multivariate (partial least squares discriminant analysis) methods using the R-based MetaboAnalyst platform. Tentative identifications of metabolites then were made using the MZedDb database. RESULTS:Significant (false discovery adjusted < 0.01) biochemical differences were observed between each of the sample groups. Biochemical changes in urine between HTpre and NT animals were linked to the tricarboxylic acid cycle, oxidative stress, steroid hormones, taurine metabolism, and phosphatidylinositol-3,4,5-trisphosphate. CONCLUSIONS:Metabolites altered in hypertensive cats were similar to those observed in other species.

Introduction2-methoxy-1,4-naphthoquinone (MNQ), a compound derived from Impatiens balsamina L., is recognized for its anti-inflammatory and antioxidant properties. However, the effects of D19, a derivative of MNQ, remain unexplored. This study aimed to elucidate the protective effect of D19 against lipopolysaccharide (LPS)-induced follicular granulosa cells (GCs) dysfunction in sheep and its underlying molecular mechanisms.MethodsAn in vitro model of GCs injury was established using LPS to induce inflammation and oxidative stress. The effects of D19 were evaluated by examining inflammatory response, oxidative stress, ferroptosis and steroidogenesis following treatment. Gene interference was applied to knock down GPX4 expression to validate its role in the protective mechanism of D19.ResultsD19 attenuated LPS-induced ferroptosis in GCs by restoring the expression of the key ferroptosis regulator GPX4. Subsequently, interfering with GPX4 activated NF-κB and upregulated the expression of inflammatory factors (TNF-α, IL-1β, IL-6) while disrupting NRF2 and inhibiting the expression of antioxidant-related factors (CAT, GSH-PX, SOD2). D19 effectively protected GCs from GPX4 deficiency-induced inflammation and oxidative damage. Furthermore, D19 mitigated ferroptosis caused by GPX4 deficiency and maintained iron metabolic homeostasis by restoring the morphology of GCs, increasing mitochondrial membrane potential, decreasing the accumulation of Fe2+ and lipid peroxides, and promoting the expression of GPX4 and FTH1. D19 also improved steroid hormone secretion abnormalities caused by GPX4 deficiency.DiscussionThese results demonstrate that D19 protects sheep follicular GCs from LPS-induced damage by modulating the GPX4-mediated ferroptosis signaling pathway, providing new potential drugs and therapeutic targets for addressing GCs dysfunction and follicular developmental abnormalities.

Abscisic acid (ABA) regulates key plant processes, including seed germination, dormancy, and abiotic stress responses. While its physiological role in germination is well-documented, the molecular mechanisms are still poorly understood. To address this, we analyzed transcriptomic and metabolomic changes in ABA-treated germinating barley (Hordeum vulgare) embryos. To map ABA-responsive gene expression across embryonic tissues, we employed the Visium Spatial Transcriptomics (10× Genomics). This approach, which remains technically challenging to be applied in plant tissues, enabled the precise localization of gene expression across six embryo regions, offering insights into tissue-specific expression patterns that cannot be resolved by traditional RNA-seq. Transcriptomic analysis indicated that ABA acts primarily as a germination repressor. Gene ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses linked ABA-inhibited genes to energy metabolism, lignin biosynthesis, cell wall organization, and photosynthesis, while induced genes were associated with environmental adaptation and phytohormone signaling. Differentially expressed genes (DEGs) correlated with metabolites involved in phytohormone pathways, including gibberellins, jasmonates, brassinosteroids, salicylic acid, auxins, and ABA metabolism. Comparisons with developing seed transcriptomes suggested an ABA-associated gene expression signature in embryos. Spatial transcriptomics technique made possible the precise identification of ABA-induced transcriptional changes within distinct embryonic tissues. Integrating transcriptomics, metabolomics and spatial transcriptomics defined the molecular signature of ABA-induced modulation of phytohormonal crosstalk, energy metabolism, and tissue-specific gene activity in germinating seeds. The successful use of spatial transcriptomics adds a novel layer of resolution for understanding tissue-specific ABA responses during barley seed germination. These findings offer new insights into the ABA role in seed germination and potential strategies for enhancing crop resilience.

Oats (Avena sativa L) is a temperate cereal and an important healthy cereal cultivated for food and feed. Therefore, understanding drought responses in oats could significantly impact oat production under harsh climatic conditions. In particular, drought during anthesis (flowering) affects grain filling, quality and yield. Here, we characterised metabolite responses of two Mediterranean oat (Avena sativa L.) cultivars, Flega and Patones, during drought stress at anthesis. In the more drought-tolerant Patones, the developing grains from the top (older) and bottom (younger) spikelets of primary panicle were found to be larger in size in response to drought, suggesting accelerated grain development. Flega showed a more rapid transition to flowering and grain development under drought. The metabolomes of source (sheath, flag leaf, rachis) and sink (developing grains) tissues from Patones showed differential accumulation in fatty acids levels, including α-linolenic acid, sugars and amino acids with drought. Flega showed enhanced energy metabolism in both source and sink tissues. Lower levels of glutathione in source tissues and the accumulation of ophthalmic acid in the grains of Flega were indicators of oxidative stress. Our study revealed two distinct metabolite regulatory patterns in these cultivars during drought at anthesis. In Patones, α-linolenic acid-associated processes may accelerate grain-filling, while in Flega oxidative stress appears to influence traits such as flowering time. Overall, this work provides a first insight into the metabolite regulation in oat's source and sink tissues during anthesis under drought stress.

Idiopathic pulmonary fibrosis (IPF) is a disease with a poor prognosis and no curative therapies. Fibroblast activation by transforming growth factor β1 (TGFβ1) and disrupted metabolic pathways, including the arginine–polyamine pathway, play crucial roles in IPF development. Polyamines are agonists of the calcium/cation-sensing receptor (CaSR), activation of which is detrimental for asthma and pulmonary hypertension, but its role in IPF is unknown. To address this question, we evaluated polyamine abundance using metabolomic analysis of IPF patient saliva. Furthermore, we examined CaSR functional expression in human lung fibroblasts (HLFs), assessed the anti-fibrotic effects of a CaSR antagonist, NPS2143, in TGFβ1-activated normal and IPF HLFs by RNA sequencing and immunofluorescence imaging, respectively; and NPS2143 effects on polyamine synthesis in HLFs by immunoassays. Our results demonstrate that polyamine metabolites are increased in IPF patient saliva. Polyamines activate fibroblast CaSR in vitro, elevating intracellular calcium concentration. CaSR inhibition reduced TGFβ1-induced polyamine and pro-fibrotic factor expression in normal and IPF HLFs. TGFβ1 directly stimulated polyamine release by HLFs, an effect that was blocked by NPS2143. This suggests that TGFβ1 promotes CaSR activation through increased polyamine expression, driving a pro-fibrotic response. By halting some polyamine-induced pro-fibrotic changes, CaSR antagonists exhibit disease-modifying potential in IPF onset and development.

Tan Spot disease is caused by the necrotrophic pathogen Pyrenophora tritici-repentis (Ptr) and poses a significant threat to global wheat production. Therefore, novel sources of resistance need to be identified, coupled with a fuller mechanistic understanding of host responses to Ptr. Herein, we characterise the interaction between a ToxA-positive Ptr strain and parental wheat lines from a multiparent advanced generation intercross (MAGIC) population. Genotypes displaying moderate resistance ('Robigus') or susceptibility ('Hereward') to Ptr challenge were identified and characterised through histological, metabolomic, and transcriptomic approaches. Histological investigations indicated the prominence of papilla-based defences in Robigus. Transcriptomic analyses could link this to the expression of barrier-related genes i.e. actin polymerisation, callose deposition, vesicle trafficking, and cellulose synthesis. Inhibiting actin polymerisation with cytochalasin E increased lesion numbers but did not augment lesion growth, suggesting the deployment of other defence mechanisms. These may be influenced by auxin, as its exogenous application exacerbated symptom development. Transcriptomic and metabolomic analyses in Hereward following challenge with Ptr suggested shifts in primary metabolism, affecting glycolysis, the TCA cycle, and the γ-aminobutyric acid (GABA) shunt. Activation of salicylic acid (SA)-associated genes, including NPR1 and WRKY33, was specific to Hereward, and exogenous SA increased susceptibility to Ptr in both genotypes. This study suggests barrier defences could be effective against Ptr as well as a lack of susceptibility factors like SA or the appropriate processing of IAA. These findings offer potential avenues for enhancing wheat resistance to Ptr.

Bitter orange flowers (BOF), a renowned medicinal and edible botanical resource, are rich in phenolic compounds with significant potential for health and industrial applications. However, efficient extraction and purification techniques for recovering bioactive phenolics remain underexplored. To address this gap, this study aimed to develop an eco-friendly integrated strategy combining natural deep eutectic solvent-ultrasound synergistic extraction (NADES-USE) with adsorptive purification for efficient recovery of total phenolics from BOF (BOF-TP). First, choline chloride-ethylene glycol (ChCl-EG) was determined to be the optimal extraction solvent from 12 synthesized NADESs and 3 common solvents. Employing Box-Behnken design (BBD), the optimized parameters for NADES-USE (38 % aqueous ChCl-EG, 18 mL/g, 345 W, 43 min, and 55 °C) resulted in a BOF-TP yield of 104.58 ± 0.34 mg/g, which was 1.30 to 2.16 times higher than those achieved with conventional solvents. Then, AB-8 resin demonstrated optimal adsorption-desorption performance for BOF-TP, with adsorption behavior strongly conforming to Langmuir isotherm and pseudo-second-order kinetic models. Thermodynamic analysis confirmed a spontaneous, exothermic physisorption process with decreasing entropy. The breakthrough curves and gradient elution curves were utilized to establish a chromatographic purification process for crude BOF-TP extracts, achieving a purity of 75.62 ± 0.95 %. Finally, a validated UPLC-Q/TOF-MS/MS method facilitated comprehensive chemical characterization and simultaneous quantification of seven bioactive compounds, serving as a basis for the quality control of purified BOF-TP extracts. In conclusion, this work demonstrates that the combination of NADES-USE and adsorptive purification offers significant potential for producing highly purified BOF-TP extract for further use in food and pharmaceutical applications.

Fagopyrum tataricum (Tartary buckwheat) is known for its high phenolic content, particularly rutin. High concentrations of these compounds secreted in the tissue culture medium can lead to its darkening and the eventual death of explants in in vitro cultures. This study aims to enhance the morphogenesis of F. tataricum callus cultures by utilising phenylalanine ammonia-lyase (PAL) inhibitors and polyvinylpyrrolidone (PVP) to mitigate oxidative browning and improve tissue viability. We analysed the response of protoplasts isolated from morphogenic callus to media supplemented with varying concentrations of PAL inhibitors (AIP, AOPP, OBHA) and PVP. The flow cytometry results revealed that 10 µM AIP and 1

Foxtail millet is a C4 crop rich in folate (FA). This study explores the roles of the 4-amino-4-deoxychorismate lyase (ADCL) - a member of the transaminase IV group of enzymes - in FA metabolism and conferred phenotypes. Phylogenetic comparisons identified diversity in the transaminase IV/ADCL gene family in the foxtail millet genome which was associated with genomic duplications. Molecular docking studies suggested that SiADCL1 bound most strongly to aminodeoxychorismate (ADC) and most likely had the highest catalytic activities. SiADCL1 which was highly expressed in roots, peduncles and flag leaves. Over-expression of SiADCL1 in Arabidopsis significantly increased total FA content (1.14-1.84 fold) and this was linked to a delayed flowering time. Metabolomic and transcriptomic characterization of the derived over-expression lines, found that FA promotes the change of methylation-related genes, ethylene synthesis, amino acid metabolism and flowering-related genes. This study revealed a potential gene coexpression network linked with FA and targeted key genes that could be exploited in foxtail millet breeding programs.

Stroke is one of the leading causes of adult disability affecting millions of people worldwide. Post-stroke cognitive and motor impairments diminish quality of life and functional independence. There is an increased risk of having a second stroke and developing secondary conditions with long-term social and economic impacts. With increasing number of stroke incidents, shortage of medical professionals and limited budgets, health services are struggling to provide a care that can break the vicious cycle of stroke. Effective post-stroke recovery hinges on holistic, integrative and personalized care starting from improved diagnosis and treatment in clinics to continuous rehabilitation and support in the community. To improve stroke care pathways, there have been growing efforts in discovering biomarkers that can provide valuable insights into the neural, physiological and biomechanical consequences of stroke and how patients respond to new interventions. In this review paper, we aim to summarize recent biomarker discovery research focusing on three modalities (brain imaging, blood sampling and gait assessments), look at some established and forthcoming biomarkers, and discuss their usefulness and complementarity within the context of comprehensive stroke care. We also emphasize the importance of biomarker guided personalized interventions to enhance stroke treatment and post-stroke recovery.

Postharvest events enhance fruit palatability, fragrance and sweetness and reduce sourness. With passion fruit (Passiflora edulis) the underlying molecular events occurring during the postharvest period remain largely unknown. In this study we define how passion fruit flavor alters during the postharvest period using integrated transcriptome and metabolome analyses. Passion fruits were stored under three conditions: room temperature, low temperature, and room temperature with a pre-fumigation with 100 mu M methyljasmonate (MeJA). During the postharvest period, organic acid content decreased but sugars and most volatiles increased. While both low temperature and MeJA treatment effectively delayed the aging process, MeJA better maintained fruit flavor. Transcriptomic and network modelling analyses targeted PeWRKY20 was a potential key regulator of the flavor of passion fruit. PeWRKY20 was shown to bind to the Malate Dehydrogenase 1 (PeMDH1) promoter to represses PeMDH1 expression. Transient assays in Nicotiana benthamiana leaves suggested that PeWRKY20 and PeMDH1 function oppositely to regulate the production of malic acid and volatiles, such as heptadecane, dimeththyl phthalate, and L-alpha-terpineol. Our work unravels a key regulatory hub in postharvest passion fruit development based on an association between malic acid and volatiles.

Introduction Tan Spot (TS) disease of wheat is caused by Pyrenophora tritici-repentis ( Ptr ), where most of the yield loss is linked to diseased flag leaves. As there are no fully resistant cultivars available, elucidating the responses of wheat to Ptr could inform the derivation of new resistant genotypes. Objectives The study aimed to characterise the flag-leaf metabolomes of two spring wheat cultivars ( Triticum aestivum L. cv. PF 080719 [PF] and cv. Fundacep Horizonte [FH]) following challenge with Ptr to gain insights into TS disease development. Methods PF and FH plants were inoculated with a Ptr strain that produces the necrotrophic toxin ToxA. The metabolic changes in flag leaves following challenge (24, 48, 72, and 96 h post-inoculation [hpi]) with Ptr were investigated using untargeted flow infusion ionisation-high resolution mass spectroscopy (FIE-HRMS). Results Both cultivars were susceptible to Ptr at the flag-leaf stage. Comparisons of Ptr - and mock-inoculated plants indicated that a major metabolic shift occurred at 24 hpi in FH, and at 48 hpi in PF. Although most altered metabolites were genotype specific, they were linked to common pathways; phenylpropanoid and flavonoid metabolism. Alterations in sugar metabolism as well as in glycolysis and glucogenesis pathways were also observed. Pathway enrichment analysis suggested that Ptr -triggered alterations in chloroplast and photosynthetic machinery in both cultivars, especially in FH at 96 hpi. In a wheat- Ptr interactome in integrative network analysis, “flavone and flavonol biosynthesis” and “starch and sucrose metabolism” were targeted as the key metabolic processes underlying PF–FH– Ptr interactions. Conclusion These observations suggest the potential importance of flavone and flavonol biosynthesis as well as bioenergetic shifts in susceptibility to Ptr . This work highlights the value of metabolomic approaches to provide novel insights into wheat pathosystems.