Nickel-induced oxidative stress and phospholipid remodeling in cucumber leaves.

Nickel phytotoxicity has been attributed, among others, to oxidative stress. However, little is known about Ni-induced phospholipid modifications, including the oxidative ones. Accumulation of reactive oxygen species (ROS), antioxidative enzyme activities, malondialdehyde and the early lipid oxidation products contents, membrane permeability, phospholipid profile as well as phospholipid unsaturation degree were studied in the 1st and the 2nd leaves of hydroponically grown cucumber seedlings subjected to Ni stress. Compared to the 2nd leaf the 1st one showed stronger visual Ni toxicity symptoms, higher Ni, O2.- and H2O2 accumulation as well as greater enhancement in membrane permeability. Enzyme activities were differently influenced by Ni stress, however most pronounced changes were generally found in the 1st leaf. Ni treatment resulted in oxidation of leaf lipids, which was evidenced by appearance of increased contents of MDA and the early produced oxylipins. Among the latter 9-hydroxyoctadecatrienoic acid (9-HOTrE) and 13-hydroxyoctadecatrienoic acid (13-HOTrE) contents showed the most pronounced increase in response to Ni treatment. Exposure to the metal led to the changes in the leaf phospholipid profile and increased degree of phospholipid unsaturation. The obtained results have been discussed in relation to the difference in Ni stress severity between the 1st and the 2nd leaves.

A new long-acting analgesic formulation for postoperative pain management.

Local anesthetics (LA), as part of multimodal analgesia, have garnered significant interest for their role in delaying the initiation of opioid therapy, reducing postoperative opioid usage, and mitigating both hospitalization duration and related expenses. Despite numerous endeavors to extend the duration of local anesthetic effects, achieving truly satisfactory long-acting analgesia remains elusive. Drawing upon prior investigations, vesicular phospholipid gels (VPGs) emerge as promising candidates for extended-release modalities in small-molecule drug delivery systems. Therefore, we tried to use the amphiphilicity of phospholipids to co-encapsulate levobupivacaine hydrochloride and meloxicam, two drugs with different hydrophilicity, to obtain a long-term synergistic analgesic effect. Initially, the physicochemical attributes of the formulation were characterized, followed by an examination of its in vitro release kinetics, substantiating the viability of extending the release duration of the dual drugs. Sequentially, in vivo investigations encompassing pharmacokinetic profiling and assessment of analgesic efficacy were undertaken, revealing a prolonged release duration of up to 120 h and attainment of optimal postoperative analgesia. Subsequently, inquiries into the mechanism underlying synergistic analgesic effects and safety evaluations pertinent to the delivery strategy were pursued. In summation, we successfully developed a promising formulation to achieve long-acting analgesia.

Cryo-EM reconstruction of oleate hydratase bound to a phospholipid membrane bilayer.

Oleate hydratase (OhyA) is a bacterial peripheral membrane protein that catalyzes FAD-dependent water addition to membrane bilayer-embedded unsaturated fatty acids. The opportunistic pathogen Staphylococcus aureus uses OhyA to counteract the innate immune system and support colonization. Many Gram-positive and Gram-negative bacteria in the microbiome also encode OhyA. OhyA is a dimeric flavoenzyme whose carboxy terminus is identified as the membrane binding domain; however, understanding how OhyA binds to cellular membranes is not complete until the membrane-bound structure has been elucidated. All available OhyA structures depict the solution state of the protein outside its functional environment. Here, we employ liposomes to solve the cryo-electron microscopy structure of the functional unit: the OhyA•membrane complex. The protein maintains its structure upon membrane binding and slightly alters the curvature of the liposome surface. OhyA preferentially associates with 20-30 nm liposomes with multiple copies of OhyA dimers assembling on the liposome surface resulting in the formation of higher-order oligomers. Dimer assembly is cooperative and extends along a formed ridge of the liposome. We also solved an OhyA dimer of dimers structure that recapitulates the intermolecular interactions that stabilize the dimer assembly on the membrane bilayer as well as the crystal contacts in the lattice of the OhyA crystal structure. Our work enables visualization of the molecular trajectory of membrane binding for this important interfacial enzyme.

Rescue of Familial Lecithin:Cholesterol Acyltranferase Deficiency Mutations with an Allosteric Activator.

Lecithin:cholesterol acyltransferase (LCAT) deficiencies represent severe disorders characterized by aberrant cholesterol esterification in plasma, leading to life-threatening conditions. This study investigates the efficacy of Compound 2, a piperidinyl pyrazolopyridine allosteric activator that binds the membrane-binding domain of LCAT, in rescuing the activity of LCAT variants associated with disease. The variants K218N, N228K, and G230R, all located in the cap and lid domains of LCAT, demonstrated notable activity restoration in response to Compound 2. Molecular dynamics simulations and structural modeling indicate that these mutations disrupt the lid and membrane binding domain, with Compound 2 potentially dampening these structural alterations. Conversely, variants such as M252K and F382V in the cap and a/b-hydrolase domain, respectively, exhibited limited or no rescue by Compound 2. Future research should prioritize in vivo investigations that would validate the therapeutic potential of Compound 2 and related activators in familial LCAT deficiency patients with mutations in the cap and lid of the enzyme. Significance Statement Lecithin:cholesterol acyltranferase (LCAT) catalyzes the first step of reverse cholesterol transport, namely the esterification of cholesterol in HDL particles. Somatic mutations in LCAT lead to excess cholesterol in blood plasma and, in severe cases, kidney failure. In this study we show that recently discovered small molecule activators can rescue function in LCAT deficient variants when the mutations occur in the lid and cap domains of the enzyme.

Untargeted metabolomics reveals the mechanism of amantadine toxicity on Laminaria japonica.

The antiviral agent amantadine is frequently detected in seawater and marine organisms. Because of increasing concentrations, amantadine has become a contaminant of emerging concern. This compound has toxic effects on the brown algae Laminaria japonica. The effects of amantadine on the biological processes of L. japonica and the corresponding toxic mechanisms remain unclear. In this study, amantadine toxicity on L. japonica was investigated using histopathological and physiological characteristics combined with metabolomics analysis. Changes in metabolites were determined by untargeted metabolomics after exposure to 107 ng/L amantadine for 72 h. The catalase activity in the exposure group slightly increased, whereas the superoxide dismutase activity greatly decreased. An increase in the malondialdehyde concentration was observed after amantadine exposure, which suggested that lipid peroxidation and cell damage occurred. Metabolomics analysis showed that there were 406 differentially expressed metabolites after amantadine exposure. These were mainly phospholipids, amino acids, purines, and their derivatives. Inhibition of the glycerophospholipid metabolism affected the lipid bilayer and cell structure, which was aligned with changes in histological observation. Changes in amino acids led to perturbation of protein synthesis and induced oxidative stress through interference with glutathione metabolism and tyrosine metabolism. Amantadine also interfered with energy metabolism in L. japonica by disturbing the tricarboxylic acid cycle and purine metabolism. The results of this study provide new insights into the mechanism of amantadine toxicity on L. japonica.

Esterified styrene-maleic acid copolymer modified silica as mixed-mode polymer-brush stationary phases for chromatographic separation.

Styrene-maleic acid (SMA) copolymer has received much attention for its excellent solubilization characteristics. In this work, SMA copolymer brush-based chromatographic stationary phases were exploited and developed for the first time. First, SMA copolymer brush was in situ grown on the surface of spherical silica via living/controlled reversible addition-fragmentation chain transfer (RAFT) polymerization method. Subsequently, as a proof-of-concept demonstration, the copolymer was esterified by diethylene glycol mono-2-ethylhexyl ether (DGME) and 2-(2-ethylhexyloxy) ethanol (EHOE), respectively. The obtained Sil-SMA-DGME and Sil-SMA-EHOE copolymer-brush chromatographic stationary phases were characterized by transmission electron microscopy, Fourier transform infrared spectrometer, X-ray photoelectron spectroscopy, and thermogravimetric analysis, respectively. The chromatographic retention mechanism indicated that both the two packed columns exhibited hydrophilic/reverse mixed-mode retention modes. The maximum column efficiency was up to 71,000 N/m. The chromatographic separation performance evaluation indicated that the novel kind of stationary phases had excellent separation capabilities for hydrophilic, hydrophobic compounds and phospholipid standards. In addition, by combination with mass spectrometry identification, the Sil-SMA-DGME column was further exploited for separation and identification of phospholipids in human lung cancer cells. Totally, 9 classes including 186 phospholipid species were successfully identified. The results demonstrated the promising application prospects of the novel kind of SMA copolymer-brush chromatographic stationary phases.

A Comparative Study on the Composition and Structure of Human Milk Phospholipids and its Natural Resources: Based on a Similarity Evaluation Model.

Human milk phospholipids (HMPLs) play an indispensable role in the neurodevelopment and growth of infants. In this study, a total of 37 phospholipid fatty acid (PLFA) species and 139 phospholipid molecular species were detected from human milk and other natural phospholipid sources (including 5 animal-derived species and 2 plant species). Moreover, a similarity evaluation model for HMPLs was established, including phospholipid classes, PLFAs, and phospholipid molecular species, to evaluate their natural substitutes. The closest scores for HMPL substitute in these three dimensions was 0.89, 0.72, and 0.77, which belonged to mare milk, goat milk, and camel milk, respectively. The highest comprehensive similarity score was obtained by camel milk at 0.75, while the lowest score was observed in soybean phospholipid (0.22). Therefore, these results not only monitored the stereochemical structure of HMPLs and their substitutes, but also further provided new insights for the development of infant formulae.

The non-enzymatic oxidation of phosphatidylethanolamine and phosphatidylserine and their intriguing roles in inflammation dynamics and diseases.

Phosphatidylethanolamine (PE) and phosphatidylserine (PS), along with phosphatidylcholine (PC), are key phospholipids (PL) in cell membranes and lipoproteins, prone to oxidative modifications. Their oxidized forms, OxPE and OxPS, play significant roles in inflammation and immune response. This review explores their structural oxidative changes under non-enzymatic conditions and their roles in physiological and pathological contexts, influencing inflammation, and immunity. Specific oxidations of PE and PS significantly alter their physicochemical properties, leading to enhanced biological functions, reduced activity, or inactivation. OxPE may show pro-inflammatory actions, similar to well-documented OxPC, while the OxPS pro-inflammatory effects are less noted. However, OxPS and OxPE have also shown an antagonistic effect against lipopolysaccharides (LPS), suggesting a protective role against exacerbated immune responses, similar to OxPC. Further research is needed to deepen our understanding of these less-studied OxPL classes. The role of OxPE and OxPS in disease pathogenesis remains largely unexplored, with limited studies linking them to Alzheimer's disease, diabetes, rheumatoid arthritis, traumatic brain injury, and skin inflammation. These findings highlight the potential of OxPE and OxPS as biomarkers for disease diagnosis, monitoring, and therapeutic targeting.

Polar Localization Analysis of Anionic Phospholipids and Their Binding Proteins in Arabidopsis Pollen Tubes.

Pollen tubes are typical polarized growth cells whose elongation occurs only in tip regions and is highly dependent on precise and ordered exocytosis/endocytosis in the top regions of the tubes. Although anionic phospholipids have been proven to be involved in regulating vesicle trafficking and the proper localization and functions of proteins in pollen tubes, the underlying cellular and molecular mechanisms remain poorly understood. To further understand how anionic phospholipids are involved in vesicle trafficking and in the control of protein localization and functions, assay methods to analyze the polar localization of anionic phospholipids and their binding proteins, and identifying phospholipid-protein interactions, should be developed. Here, we describe detailed protocols for analyzing anionic phospholipid polar localization and colocalization with their binding proteins in Arabidopsis pollen tubes and examining phospholipid-protein interactions in vitro.

Architecture and function of yeast phosphatidate phosphatase Pah1 domains/regions.

Phosphatidate (PA) phosphatase, which catalyzes the Mg2+-dependent dephosphorylation of PA to produce diacylglycerol, provides a direct precursor for the synthesis of the storage lipid triacylglycerol and the membrane phospholipids phosphatidylcholine and phosphatidylethanolamine. The enzyme controlling the key phospholipid PA also plays a crucial role in diverse aspects of lipid metabolism and cell physiology. PA phosphatase is a peripheral membrane enzyme that is composed of multiple domains/regions required for its catalytic function and subcellular localization. In this review, we discuss the domains/regions of PA phosphatase from the yeast Saccharomyces cerevisiae with reference to the homologous enzyme from mammalian cells.

Beyond Skin Deep: Phospholipid-Based Nanovesicles as Game-Changers in Transdermal Drug Delivery.

Transdermal administration techniques have gained popularity due to their advantages over oral and parenteral methods. Noninvasive, self-administered delivery devices improve patient compliance and control drug release. Transdermal delivery devices struggle with the skin's barrier function. Molecules over 500 Dalton (Da) and ionized compounds don't permeate through the skin. Drug encapsulation in phospholipid-based vesicular systems is the most effective skin delivery technique. Vesicular carriers include bi-layered liposomes, ultra-deformable liposomes, ethanolic liposomes, transethosomes, and invasomes. These technologies enhance skin drug permeation by increasing formula solubilization, partitioning into the skin, and fluidizing the lipid barrier. Phospholipid-based delivery systems are safe and efficient, making them a promising pharmaceutical and cosmeceutical drug delivery technique. Still, making delivery systems requires knowledge about the physicochemical properties of the drug and carrier, manufacturing and process variables, skin delivery mechanisms, technological advances, constraints, and regulatory requirements. Consequently, this review covers recent research achievements addressing the mentioned concerns.

[Changes and significance of oxidized phospholipids and endothelial nitric oxide synthase in the acute stage of Kawasaki disease]. / å·å´Žç— æ€¥æ€§æœŸæ°§åŒ–ç£·è„‚å’Œå† çš®ä¸€æ°§åŒ–æ°®åˆé ¶çš„å˜åŒ–åŠæ„ä¹‰.

OBJECTIVES: To investigate the changes in the serum levels of oxidized phospholipids (OxPLs) and endothelial nitric oxide synthase (eNOS) and their association with coronary artery disease (CAL) in children in the acute stage of Kawasaki disease (KD), as well as the clinical significance of OxPLs and eNOS. METHODS: A prospective study was conducted on 95 children in the acute stage of KD (KD group). According to the presence of absence of CAL, the KD group was further divided into a CAL subgroup and a non-CAL (NCAL) subgroup. Thirty children with fever due to lower respiratory tract infection were enrolled as the fever group. Thirty healthy children who underwent physical examination were enrolled as the healthy control group. The above groups were compared in terms of general information and serum levels of OxPLs, eNOS and other laboratory indexes, and the correlation between OxPLs level and eNOS level was analyzed. RESULTS: The KD group had a significantly higher level of OxPLs and a significantly lower level of eNOS compared with the fever group and the healthy control group (P<0.05). After treatment, the children with KD had a significantly decreased OxPLs level and a significantly increased eNOS level (P<0.05). Compared with the NCAL subgroup, the CAL subgroup had a significantly higher level of OxPLs and a significantly lower level of eNOS (P<0.05). Among the children of KD, the level of OxPLs was negatively correlated with that of eNOS (rs=-0.353, P<0.05). CONCLUSIONS: Serum OxPLs and eNOS in the acute stage of KD may be involved in the development of CAL in children with KD, and therefore, they may be used as the biomarkers to predict CAL in these children.

Evaluation of simplified ester-linked fatty acid analysis (ELFA) for phospholipid fatty acid (PLFA) analysis of bacterial population.

Phospholipid fatty acid (PLFA) analysis is used for characterizing microbial communities based on their lipid profiles. This method avoids biases from PCR or culture, allowing data collection in a natural state. However, PLFA is labor-intensive due to lipid fractionation. Simplified ester-linked fatty acid analysis (ELFA), which skips lipid fractionation, offers an alternative. It utilizes base-catalyzed methylation to derivatize only lipids, not free fatty acids, and found glycolipid and neutral lipid fractions are scarcely present in most bacteria, allowing lipid fractionation to be skipped. ELFA method showed a high correlation to PLFA data (r = 0.99) and higher sensitivity than the PLFA method by 1.5-2.57-fold, mainly due to the higher recovery of lipids, which was 1.5-1.9 times higher than with PLFA. The theoretical limit of detection (LOD) and limit of quantification (LOQ) for the ELFA method indicated that 1.54-fold less sample was needed for analysis than with the PLFA method. Our analysis of three bacterial cultures and a simulated consortium revealed the effectiveness of the ELFA method by its simple procedure and enhanced sensitivity for detecting strain-specific markers, which were not detected in PLFA analysis. Overall, this method could be easily used for the population analysis of synthetic consortia.

The influence mechanism of phospholipids structure and composition changes caused by oxidation on the formation of flavor substances in sturgeon caviar.

The oxidation-induced phospholipids (PLs) underwent structural and compositional analysis, alongside the establishment of a simulation system to verify the link between phospholipid oxidation and flavor substances formation in sturgeon caviar. Structural alterations of PLs were tracked using 31P and 1H nuclear magnetic resonance (NMR), electron spin resonance spectroscopy (ESR), and Raman spectroscopy. The findings revealed a reduction in phosphatidylcholine (PC) and phosphatidylethanolamine (PE) from 82.3% and 10.4% to 58.2% and 5.8% respectively. Free radical signals exhibited an initial increase followed by a decrease. The diminished intensity in Raman spectra at 970 and 1080 cm-1 indicated reduced fat unsaturation attributable to PLs oxidation. Correlation analysis highlighted a significant association between PC and PE containing C22:6, C20:5, C20:4, and C18:2 with flavor substances, suggesting their role as key precursors for flavor development. This study established a theoretical basis for understanding the change of flavor quality in sturgeon caviar during storage.

Extracellular vesicles as a hydrolytic platform of secreted phospholipase A2.

Extracellular vesicles (EVs) represent small vesicles secreted from cells, including exosomes (40-150 nm in diameter), which are released via the multivesicular endosomal pathway, and microvesicles and ectosomes (100-1000 nm), which are produced by plasma membrane budding. Broadly, EVs also include vesicles generated from dying cells, such as apoptotic bodies (5-10 µm), as well as exomeres (< 50 nm), which are very small, non-membranous nanoparticles. EVs play important roles in cell-to-cell signaling in various aspects of cancer, immunity, metabolism, and so on by transferring proteins, microRNAs (miRNAs), and metabolites as cargos from donor cells to recipient cells. Although lipids are one of the major components of EVs, they have long been recognized as merely the "wall" that partitions the lumen of the vesicle from the outside. However, it has recently become obvious that lipid composition of EVs influences their properties and functions, that EVs act as a carrier of a variety of lipid mediators, and that lipid mediators are produced in EV membranes by the hydrolytic action of secreted phospholipase A2s (sPLA2s). In this article, we will make an overview of the roles of lipids in EVs, with a particular focus on sPLA2-driven mobilization of lipid mediators from EVs and its biological significance.

Short leukocyte telomere length and high plasma phospholipid fatty acids increase the risk of type 2 diabetes.

In the last 40 years, there has been a notable rise in the occurrence of diabetes within China, leading to the country now having the highest number of individuals affected by this condition globally. This prospective observational study examined the effect of different baseline relative leukocyte telomere length (RTL) and the combined effect of baseline RTL and plasma phospholipid fatty acid (PPFA) on the risk of developing diabetes. Adults from Ningxia Province who underwent baseline and follow-up surveys were included in the study. The correlation between the baseline RTL and PPFA was investigated using a multiple linear regression model. The combined effects of baseline RTL and PPFA levels on the risk of developing type 2 diabetes mellitus (T2DM) were investigated using a Cox regression model with time as the covariate. A total of 1461 study subjects were included in this study. According to the diagnostic criteria of the Chinese Diabetes Society, 141 subjects developed T2DM during the follow-up period. The baseline age was negatively correlated with RTL. After adjustment for age, C16:0, C18:1 n-9, C20:4 n-6, C20:3 n-3, and monounsaturated fatty acid (MUFA) concentrations were negatively correlated with RTL. Multiple linear regression analysis showed that C16:0 and MUFA concentrations influenced RTL. Subjects with shorter RTL at baseline had a higher risk of developing diabetes than those with longer RTL. Subjects with shorter RTL and higher C16:0 and MUFA concentrations at baseline had a higher risk of developing T2DM than those with longer RTL and lower C16:0 and MUFA concentrations. Our findings indicated that PPFA affects changes in RTL. In addition, RTL and PPFA are associated with the occurrence of T2DM.

Antibacterial effect of the metal nanocomposite on Escherichia coli.

Ag nanocomposites (NAs) have been found to induce irreversible harm to pathogenic bacteria, however, NAs tend to aggregate easily when used alone. These nanocomposites also show increased toxicity and their underlying antibacterial mechanism is still unknown. In short, practical applications of NA materials face the following obstacles: elucidating the mechanism of antibacterial action, reducing cytotoxicity to body cells, and enhancing antibacterial activity. This study synthesized a core-shell structured ZnFe2O4 @Cu-ZIF-8 @Ag (FUA) nanocomposite with high antibacterial activity and low cytotoxicity. The nanocomposites achieved a 99.99 % antibacterial rate against Escherichia coli (E. coli) and tetracycline-resistant E. coli (T - E. coli), in under 20 min at 100 µg/mL. The nanocomposites were able to inactivate E. coli due to the gradual release of Cu2+, Zn2+, and Ag+ ions, which synergistically form •OH from FUA in an aerobic environment. The presence of •OH has significant effects on the antibacterial activity. The released metal ions combine with •OH to cause damage to the bacterial cell wall, resulting in the leakage of electrolytes and ions. Moreover, in comparison to NA, the toxicity of FUA is considerably reduced. This study is expected to inspire the development of other silver-based nanocomposite materials for the inactivation of drug-resistant bacteria.

UPLC-MS based lipidomics analysis on optimization of soybean phosphatidylethanolamine extraction.

Soybean-derived phosphatidylethanolamine (PE) is a valuable phospholipid component yet its high-purity form is costly and its molecular structure is poorly understood. The present study combined solvent extraction and cryopurification to purify PE. The optimal extraction conditions were as follows: material-liquid ratio 1:15 (g/mL), ethanol base concentration 100:4 (Vanhydrous ethanol /V25% ammonia), extraction temperature 40 °C, time 60 min, extraction twice. The cryopurification conditions were: material-liquid ratio 1:60, ethanol base concentration 100:6 (Vanhydrous ethanol/V25% ammonia), freezing temperature - 20 °C, time 20 h. UPLC-QTOF-MS/MS analysis revealed phospholipid composition of raw material, crude product, and purified product. The results showed that the purity of PE in the purified products was 76.74%, and the yield was 72.43% under optimal conditions. 181 phospholipid molecules were quantified. The study successfully explored high-purity PE preparation method and the composition of PE product. It provides a basis for the subsequent exploration of its biofunction and potential applications.

Successful treatment with rituximab in anti-phospholipid syndrome nephropathy associated with systemic lupus erythematosus: A case report and literature review.

Anti-phospholipid syndrome (APS) nephropathy is an autoimmune disease that is sometimes accompanied by systemic lupus erythematosus (SLE). Here, we report the use of rituximab to treat a case of APS nephropathy in a SLE patient with recurrent vascular thrombosis. A 52-year-old woman, who had been diagnosed with SLE 11 years earlier, was referred to a nephrology clinic for evaluation of azotaemia and proteinuria. She had experienced spontaneous abortion at 35 years of age. The patient had been diagnosed with right popliteal thrombosis at 39 years of age, and with left pulmonary artery thrombosis and SLE at 41 years of age. Before admission, she was undergoing anticoagulant and immunosuppressive therapies, with follow-up in the rheumatology clinic. At her last outpatient clinic visit before admission, she exhibited mild bilateral lower-limb pitting oedema, impaired renal function and proteinuria. Renal biopsy revealed arteriolar wall thickening, with thrombi in the capillary lumina and marked inflammatory cell infiltration in the interstitium. The patient was treated with warfarin and high-dose corticosteroids. Intravenous rituximab (500 mg) was also administered twice at a 4-week interval. Her renal function did not worsen any further, and her proteinuria decreased. Here we report the successful use of rituximab to treat APS nephropathy in a patient with SLE, who had progressive renal insufficiency.

Growing in phosphorus-impoverished habitats in south-western Australia: How general are phosphorus-acquisition and -allocation strategies among Proteaceae, Fabaceae and Myrtaceae species?

Numerous phosphorus (P)-acquisition and -utilisation strategies have evolved in plants growing in severely P-impoverished environments. Although these strategies have been well characterised for certain taxa, like Proteaceae, P-poor habitats are characterised by a high biodiversity, and we know little about how species in other families cope with P scarcity. We compared the P-acquisition and leaf P-allocation strategies of Fabaceae and Myrtaceae with those of Proteaceae growing in the same severely P-impoverished habitat. Myrtaceae and Fabaceae exhibited multiple P-acquisition strategies: P-mining by carboxylates or phosphatases, P uptake facilitated by carboxylate-releasing neighbours, and dependence on the elevated soil P availability after fire. Surprisingly, not all species showed high photosynthetic P-use efficiency (PPUE). Highly P-efficient species showed positive correlations between PPUE and the proportion of metabolite P (enzyme substrates), and negative correlations between PPUE and phospholipids (cellular membranes) and nucleic acid P (mostly ribosomal RNA), while we found no correlations in less P-efficient species. Overall, we found that Myrtaceae and Fabaceae used a wider range of strategies than Proteaceae to cope with P scarcity, at both the rhizosphere and leaf level. This knowledge is pivotal to better understand the mechanisms underlying plant survival in severely nutrient-impoverished biodiverse ecosystems.