Phytophthora nicotianae is a plant-pathogenic oomycete, posing a serious threat to global agriculture due to its highly destructive infections and challenges in management. To explore a biologically based disease management strategy, we investigated Streptomyces ardesiacus HL-06, which produces phenazine-1-carboxamide (PCN), a potent anti-oomycete metabolite that effectively suppresses the growth of P. nicotianae in vitro and reduces tobacco black shank severity by over 80% under field conditions, surpassing the efficacy of commercial fungicides. Mechanistically, we identified CDC48, a AAA+ ATPase essential for mitochondrial homeostasis, as the direct molecular target of PCN. Drug affinity responsive target stability (DARTS), molecular docking, and isothermal titration calorimetry revealed that PCN binds to CDC48's ATPase domain, thereby disrupting mitochondrial protein quality control. This interaction leads to mitochondrial cristae loss, ATP synthase inhibition, and reactive oxygen species (ROS) accumulation, ultimately triggering oomycete apoptosis. This is the first report of a phenazine compound targeting a eukaryotic AAA+ ATPase, revealing a novel mode of action against oomycete pathogens. Our findings integrate microbial ecology with chemical biology, positioning PCN as a promising eco-friendly candidate for sustainable plant disease management.

CaM-binding Protein 60-like G (CBP60g) and Systemic Acquired Resistance Deficient 1 (SARD1) are key immune signalling regulators that redundantly promote salicylic acid (SA) biosynthesis and plant immunity. Pathogen effectors often target these immune nodes to suppress plant defence. However, the role of bacterial effectors in disabling CBP60g and SARD1 to increase plant susceptibility remains unclear. In this study, we show that RipAW, an E3 ligase effector from Ralstonia solanacearum , induces root architecture changes and enhances plant susceptibility to R. solanacearum in Est::RipAW transgenic plants. The constitutively expressed RipAW (C177S) , lacking E3 ligase activity, did not affect root architecture or plant susceptibility, indicating that RipAW's E3 ligase activity is crucial for these phenotypes. Transcriptional profiling of Est::RipAW plants revealed strong up-regulation of CBP60g and SARD1, while the SA signalling pathway remained in a basal state. Transient expression of RipAW and CBP60g in Nicotiana benthamiana showed that RipAW associates with CBP60g and affects its stability. Genetic analysis revealed that loss-of-function mutations in CBP60g and SARD1 increased plant susceptibility to R. solanacearum, but did not enhance RipAW-mediated pathogen growth. Furthermore, growth of the R. solanacearum Δ RipAW null mutant strain was reduced in wild-type plants but restored in cbp60g/sard1 mutant plants, confirming that the promotion of RipAW on bacterial growth is dependent on CBP60g and SARD1. Surprisingly, CBP60g and SARD1 were not involved in R. solanacearum -induced and RipAW-triggered root architecture changes. Overall, our findings demonstrate that RipAW increases plant susceptibility to R. solanacearum via both CBP60g/SARD1-dependent and -independent pathways.

Cucumber target spot, a major disease that threatens cucumber production, is caused by Corynespora cassiicola. Cyclobutrifluram, a novel succinate dehydrogenase inhibitor (SDHI) developed by Syngenta, has demonstrated strong inhibitory activity against various plant pathogenic fungi and nematodes. However, its antifungal spectrum, resistance risk as well as underlying mechanisms of resistance in C. cassiicola remain poorly understood. In this study, cyclobutrifluram exhibited potent inhibitory activity against anamorphic fungi and selected ascomycetes, with the mean sensitivity of C. cassiicola isolates to the fungicide being 0.98 ± 1.26 μg/mL. Additionally, five laboratory-derived cyclobutrifluram-resistant mutants showed comparable or lower biological fitness than their respective parental isolates. The resistant mutants and field isolates were also found to possess nine distinct point mutations in the CcSdhB, CcSdhC or CcSdhD genes. Finally, cyclobutrifluram exhibited positive cross-resistance with other SDHIs, with the resistance levels varying depending on the specific mutations present. In conclusion, cyclobutrifluram was found to be effective against anamorphic fungi and selected ascomycetes. C. cassiicola’s risk of resistance development to cyclobutrifluram was assessed as moderate to high and was primarily associated with mutations in CcSdh genes. The antifungal spectrum of cyclobutrifluram was investigated. C. cassiicola’s risk of resistance development to cyclobutrifluram was classified as moderate to high. Specific point mutations in CcSdh genes conferred resistance to cyclobutrifluram.

This study investigated the impact of lactic acid bacteria (LAB) sequential fermentation on viable counts and apple juice quality. The optimal fermentation conditions were obtained by a step-by-step optimization process, including pH 4.5, temperature 37 °C, the second inoculation time 16 h, total fermentation time 40 h and fermentation sequence (first 21,805 + 21,828, second 20,241). Under the optimal conditions, sequential fermentation allowed LAB to experience two logarithmic phases, increasing viable counts to 1.38 × 108 CFU/mL, exceeding simultaneous fermentation for 24 h and 40 h by 4.10 × 107 CFU/mL and 5.40 × 107 CFU/mL, respectively. This process enhanced sugar utilization, yielding more lactic acid and polyphenols. Furthermore, sequential fermentation improved DPPH (71.71 %) and ABTS (84.79 %) scavenging rates, and enriched volatile compounds, particularly beta-Damascenone, potentially contributing to floral and richer apple flavor. Sequential fermentation also achieved optimal sensory acceptability. This study proposes a novel strategy for high-density LAB fermentation to produce high-quality apple juice.

Fruit spine density is an important commercial trait for cucumber (Cucumis sativus L.). Most North China-type cucumbers that are grown over large areas have a dense-spine phenotype, which directly affects the appearance quality, storage, and transportation of the fruits. Here, we isolated a novel few spines mutant (fs2) from the wild-type (WT) inbred line WD1, a North China-type cucumber with high density fruit spines, by an ethyl methanesulfonate (EMS) mutagenesis treatment. Genetic analysis revealed that the phenotype of fs2 is controlled by a single recessive nuclear gene. We fine-mapped the fs2 locus using F2 and BC1 populations (1,802 and 420 individuals, respectively), which showed that the candidate gene of FS2 (Csa4G652850) encodes an ARID-HMG transcription factor containing an AT-rich interaction domain (ARID) and a high mobility group box domain (HMG). One SNP (C to T) and one InDel (a 40-bp deletion) in the coding region of FS2 result in amino acid variation and premature translation termination in the fs2 mutant, respectively. FS2 was found to be highly expressed in the apical buds and young ovaries. In addition, experiments suggest that FS2 participates in the regulation of fruit spine initiation by activating the expression of the Tril gene in cucumber. This work provides not only an important reference for understanding the molecular mechanisms of fruit spine development but also an important resource for fruit appearance quality breeding in cucumber.

Pichia kudriavzevii could resist high concentrations of sodium selenite and efficiently biotransform over 80% of the absorbed selenium. However, the specific molecular mechanisms underlying this biotransformation remain unclear. This study aimed to investigate the mechanism of selenium biotransformation focusing on selenium transport, detoxification, reduction, and the formation of organic selenium compounds through a comprehensive approach combining transcriptomic, proteomic, and non-targeted metabolomic analyze. Results showed that the JEN1 gene was responsible for selenium transport, while the upregulation of cysJ, , CYSK, , TRXB1 and sat genes as well as the involvement of glutathione, are crucial for the accumulation of organic selenium. Furthermore, GSTY2, , TRXB1 and GPX3 were pivotal genes in Se(IV) reduction and their corresponding proteins were key proteins. Additionally, the enhanced expression of genes related to antioxidant enzymes ( GSTY2 , TRXB1, , and GPX3), ), ABC transports, heat shock proteins and antioxidant enzymes proteins (GSTY2, TRXB1, and GPX3) collectively contributed to selenium tolerance, detoxification and protection against oxidative damage. GO and KEGG analysis highlighted alterations in amino acid metabolism, carbohydrate metabolism, and energy metabolism in the selenium biotransformation process. These findings provide novel insight into the mechanisms of selenium biotransformation in P. kudriavzevii and its application in the fields of the food industry.

AbstractDiverse pathogen effectors convergently target conserved components in plant immunity guarded by intracellular nucleotide‐binding domain leucine‐rich repeat receptors (NLRs) and activate effector‐triggered immunity (ETI), often causing cell death. Little is known of the differences underlying ETI in different plants triggered by the same effector. In this study, we demonstrated that effector RipAW triggers ETI on Nicotiana benthamiana and Nicotiana tabacum. Both the first 107 amino acids (N1‐107) and RipAW E3‐ligase activity are required but not sufficient for triggering ETI on N. benthamiana. However, on N. tabacum, the N1‐107 fragment is essential and sufficient for inducing cell death. The first 60 amino acids of the protein are not essential for RipAW‐triggered cell death on either N. benthamiana or N. tabacum. Furthermore, simultaneous mutation of both R75 and R78 disrupts RipAW‐triggered ETI on N. tabacum, but not on N. benthamiana. In addition, N. tabacum recognizes more RipAW orthologs than N. benthamiana. These data showcase the commonalities and specificities of RipAW‐activated ETI in two evolutionally related species, suggesting Nicotiana species have acquired different abilities to perceive RipAW and activate plant defences during plant–pathogen co‐evolution.

AbstractMicroRNAs (miRNAs) play an essential role as non‐coding‐RNA‐type epigenetic regulators in response to high‐temperature stress in plants. There are crucial roles for global transcriptional regulation under SUMO (small ubiquitin‐related MOdifier) stress response (SSR). However, the molecular mechanisms underlying its downstream regulation remain unclear. In this study, SUMO‐specific chromatin immunoprecipitation sequencing analysis detected specific binding in the promoter region of miRNAs under high‐temperature stress. A correlation analysis between this binding and miRNA profiling revealed that the location of SUMO on the chromosome was correlated with the expression pattern of miRNAs, particularly miR398a and miR824a. In contrast, knockout mutants of the SSR‐dependent SUMO E3 ligase SAP AND MIZ 1 in Arabidopsis exhibited opposing trends in target gene expression for the SUMO‐related miRNAs compared to the wild type. Multi‐omics correlation analyses identified 34 SUMO‐candidate proteins that might be involved in the regulation of miRNA response to high‐temperature stress. Therefore, we propose a potential model whereby high‐temperature exposure induces nuclear entry of SUMO molecules, modifying specific transcription factors that bind to miRNA gene promoters and potentially regulate miRNA expression.

This study researched a Se-enriched dominant Pichia kudriavzevii 1845 for its potential as a selenium (Se) supplement. The results showed that under optimal conditions, the total Se amount within Se-enriched P. kudriavzevii 1845 (SeY) was 680.86 ± 20.98 μg/g, with organic forms accounting for 84.88 ± 1.52%. Importantly, Se-enrichment did not negatively affect the ultrastructure of the strain, and nanoparticles were observed on the surface and inside of SeY. The enriched Se was transferred from the surface to the interior and evenly distributed in the cytoplasm of yeast. Additionally, Se enrichment significantly improved the probiotic abilities of the strain, including hydrophobicity and auto-aggregation. The survival rate of SeY during gastrointestinal digestion was not affected. Furthermore, SeY exhibited increased antioxidant properties, such as radical scavenging capacity and antioxidative enzymes. This research demonstrated that SeY has great potential as a Se supplement to address Se deficiency.

This study is the first to demonstrate the yeast Pichia kudriavzevii can effectively deliver Se and investigate the distribution and species of Se in Se-enriched P. kudriavzevii. Results showed that P. kudriavzevii can accumulate Se and convert 84.883% of absorbed Se into organic forms, of which 78.338% was incorporated into protein, 1.978% combined with polysaccharides, and 0.456% bound to nucleic acid. Besides, water-soluble, salt-soluble, and alkali-soluble proteins account for 49.398%, 1.867%, and 20.628% of selenoprotein, respectively. The dominant Se species were SeCys2 and MeSeCys. Additionally, Se-enrichment enhanced nutritional value of P. kudriavzevii by increasing the levels of amino acids, iron, and zinc. The activity of key rate-limiting enzyme sephosphate synthetase involved in Se biotransformation was improved after Se enrichment. The extracellular pH results suggest that Se enrichment ability can be further enhanced by elevating pH. These results suggest P. kudriavzevii holds great promise as an effective vehicle for delivering Se.

BACKGROUND:Polyamine oxidase (PAO) is a crucial enzyme involved in the breakdown of polyamines (PAs) in plants. It not only regulates the levels of PAs, but also plays a role in the oxidative decomposition of PAs and the release of stress-related signals, contributing to the plant's response and resistance to various adversities. While there have been numerous studies on the response of PAO to stress in other crops, there is a lack of research on this topic in potatoes, a major food crop. RESULTS:In this study, we aimed to explore the biological function of the StPAO gene in potato growth and development, as well as its expression patterns under stress. Using bioinformatics methods, we identified 14 StPAO genes in the potato genome. Protein sequence comparisons revealed a high similarity between the PAO proteins of potato and Arabidopsis. Chromosomal mapping and gene structure analysis showed that the StPAO genes were not evenly distributed on the chromosome and all contained an amino-oxidase domain. Furthermore, analysis of the promoters of these genes revealed the presence of abiotic and stress-related cis-acting elements, indicating their potential role in responding to different stresses. To investigate the expression patterns of these genes under stress, we used qRT-PCR to study their response to high temperature, drought, and ABA stress. Our results showed that StPAO6 and StPAO10 were significantly up-regulated under high temperature stress, indicating that they were involved in the process of potato resistance to high temperatures. Similarly, StPAO1, StPAO3, and StPAO4 were significantly up-regulated under drought stress, indicating their potential role in potatoes' responses to drought. After ABA treatment, the expression levels of StPAO4, StPAO5, StPAO7, and StPAO14 were significantly up-regulated, suggesting their involvement in chemical defense mechanisms. Interestingly, the expression of StPAO11-13 was inhibited by all three stresses. CONCLUSIONS:In conclusion, our study highlights the multifunctional nature of the StPAO gene family in potatoes, which plays a crucial role in coping with various stresses. This research deepens our understanding of the potato StPAO gene family and provides a reference for future studies on its function. It also serves as a theoretical basis for breeding stress-resistant potato varieties in the future.

Inflammatory bowel disease (IBD) poses persistent challenges due to its chronic and recurrent nature, exacerbated by the unsatisfactory outcomes of the traditional treatment approaches. In this study, we developed a dietary supplement, selenium-enriched Pichia kudriavzevii (SeY), to alleviate dextran sulfate sodium-induced colitis in mice. The newly developed functional food shows dual-functional activity, acting both as a probiotic and a reliable source of organic selenium. This study aimed to investigate the preventive effects of SeY against dextran sulfate sodium-induced colitis in mice and elucidate the underlying mechanisms. Results showed that SeY, especially at high doses (HSeY), significantly ameliorated colitis symptoms, reduced colonic damage, attenuated inflammatory responses, and mitigated oxidative stress. Furthermore, HSeY strengthened intestinal barrier function by increasing goblet cell numbers, upregulating MUC2 expression, and enhancing tight junction proteins (ZO-1, claudin-1, and occludin). Additionally, HSeY alleviated gut microbiota dysbiosis by promoting the colonization of beneficial bacteria such as norank-f-Muribaculaceae and Bacteroides, while suppressing harmful microorganisms such as norank-f-norank-o-Clostridia-UCG-014. The altered gut microbiota also affected gut metabolism, with differential metabolites primarily associated with amino acids, such as tryptophan metabolism, contributing to the mitigation of oxidative stress and inflammatory responses. Further studies involving antibiotic-mediated depletion of gut flora and fecal microbiota transfer trials corroborated that the preventive effect of HSeY against IBD relied on the gut microbiota. This study provides vital insights into colitis prevention and advances selenium-enriched fortified food-targeted nutritional interventions.

In this study, we screened probiotics with alcohol degrading function and studied the antioxidant activity of fermented apple juice and its protective effect on alcoholic liver injury in mice. Lactobacillus helveticus CICC6064 was screened by the test of alcohol degradation and simulated gastrointestinal digestion in vitro. The antioxidant activity, polyphenol and flavonol concentrations of fermented apple juice were increased. Animal experiments showed that compared with other experimental groups, Lactobacillus helveticus CICC6064 fermented apple juice could reduce the concentration of alcohol in serum of mice significantly, meanwhile, it also can protect the liver by reducing the pro-inflammatory cytokines (TNF-α, IL-1β, IL-2, and IL-6), increasing anti-inflammatory cytokines (IL-10), reducing oxidative stress in the body (increasing SOD, GST, CAT, reducing NO), reducing liver toxicity index (ALT, AST, GGT, ALP), and reducing liver lipid accumulation.

Systemic acquired resistance (SAR) is activated by local infection and confers enhanced resistance against subsequent pathogen invasion. Salicylic acid (SA) and N-hydroxypipecolic acid (NHP) are two key signaling molecules in SAR and their levels accumulate during SAR activation. Two members of plant-specific Calmodulin-Binding Protein 60 (CBP60) transcription factor family, CBP60g and SARD1, regulate the expression of biosynthetic genes of SA and NHP. CBP60g and SARD1 function as master regulators of plant immunity and their expression levels are tightly controlled. Although there are numerous reports on regulation of their expression, the specific mechanisms by which SARD1 and CBP60g respond to pathogen infection are not yet fully understood. This study identifies and characterizes the role of the LAZARUS 1 (LAZ1) and its homolog LAZ1H1 in plant immunity. A forward genetic screen was conducted in the sard1-1 mutant background to identify mutants with enhanced SAR-deficient phenotypes (sard mutants), leading to the discovery of sard6-1, which maps to the LAZ1 gene. LAZ1 and its homolog LAZ1H1 were found to be positive regulators of SAR through regulating the expression of CBP60g and SARD1 as well as biosynthetic genes of SA and NHP. Furthermore, Overexpression of LAZ1, LAZ1H1 and its homologs from Nicotiana benthamiana and potato enhanced resistance in N. benthamiana against Phytophthora pathogens. These findings indicate that LAZ1 and LAZ1H1 are evolutionarily conserved proteins that play critical roles in plant immunity.

Insufficient selenium intake can lead to serious health problems. However, most research on the functional properties of selenium-enriched probiotics has focused on sub-health conditions or disease models, with limited studies involving healthy subjects. Additionally, previous research has primarily explored the direct effects of selenium itself, neglecting its influence on gut microbiota and metabolism. This study aimed to explore whether long-term intake of Pichia kudriavzevii enriched with selenium affected gut microbiota and host metabolism in mice and to identify microbiota and metabolites related to beneficial outcomes. Results demonstrated that selenium-enriched P. kudriavzevii (SeY) exhibited non-toxic properties, did not cause colon or liver damage, enhanced antioxidant capacity, and reduced inflammation in a selenium dose-dependent manner. Additionally, SeY supplementation significantly altered the gut microbiota. High-dose SeY (HSeY) elevated the abundance of beneficial bacteria such as Lactobacillus and suppressed harmful bacteria such as Eubacterium nodatum group, Prevotellaceae_NK3B31_group, and unclassified_f__Lachnospiraceae. Low-dose SeY (LSeY) increased the abundance of Faecalibaculum. The strain without enriched selenium exhibited higher levels of Akkermansia compared to selenium-enriched strains. Both strains, with or without enriched selenium, stimulated the production of short-chain fatty acids. Non-targeted metabolomics analysis revealed that HSeY treatment regulated various metabolic pathways, such as tryptophan metabolism, tyrosine metabolism, and arginine biosynthesis. LSeY treatment modulated tyrosine metabolism, secondary bile acid metabolism, bile secretion, and primary bile acid metabolism. P. kudriavzevii regulated the metabolism of purine, arginine, proline, and tryptophan. Our study highlights the promise of SeY supplementation in regulating host metabolism and the gut microbiota, offering insights into its implications for promoting health.

Hyperuricemia has evolved into a global public health concern, and applying probiotics fermented apple juice holds promise for alleviating this condition. This study aimed to investigate the biotransformation and metabolic features of urate-lowering probiotics sequentially fermented dealcoholized apple juice (PSFA), and assess its ameliorative effects and potential mechanisms on hyperuricemia mice. Results showed that CICC 6074 and 20,292 possessed excellent purine, nucleotide and nucleoside degradation and acid and bile salt resistance; sequential fermentation decreased the fructose in apple juice, and viable counts reached 3.76 x 108 CFU/mL. Histopathological analysis showed that PSFA ameliorated kidney damage in hyperuricemia mice. Furthermore, PSFA significantly reduced Urea, Creatinine and Uric acid levels in hyperuricemia mice; and inhibited xanthine oxidase activity and the expression of pro-inflammatory factors. Importantly, PSFA reversed gut microbiota dysbiosis and raised the abundance of beneficial bacteria (Lactobacillush, Faecalibaculum and Lachnospiraceae_NK4A136_group). KEGG and COG functional prediction results revealed that the potential mechanism of PSFA to ameliorate hyperuricemia may be lipid metabolism and glycolysis pathways.

Cytokinin signalling plays both positive and negative roles in plant resistance to pathogens. It is not clear whether the role of cytokinin changes at the different stages of pathogen infection. Arabidopsis thaliana sequentially exhibits distinct root morphological symptoms during Ralstonia solanacearum infection, which offers a good system to investigate function of cytokinin in the whole pathogen infection process. Using this system, we found increase of cytokinin signalling by Lonely Guy 2 (LOG2) overexpression or depletion of type-A Arabidopsis Response Regulators (ARRs), negative regulators of cytokinin signalling pathway, promoted cell death, wilting symptom and bacterial growth, but attenuated primary root growth inhibition and lateral root formation. The decrease of cytokinin signalling by mutation on Isopentenyl Transferases (IPTs) inhibited root hair formation, cell death, wilting symptom and bacterial colonisation. Application of different concentration of exogenesis 6-benzylaminopurine (6-BA) showed first promoted, then decreased root hair formation. Moreover, application of 6-BA accelerated cell death but suppressed lateral root formation and primary root growth inhibition. The diverse roles of cytokinin in these different root disease phenotypes suggested function of cytokinin during plant responses to R. solanacearum is cell type-specific, which provides new insights on roles of cytokinin signalling in regulation on plant-pathogen interactions.

Glutathione peroxidase-like enzyme is an important enzymatic antioxidant in plants. It is involved in scavenging reactive oxygen species, which can effectively prevent oxidative damage and improve resistance. GPXL has been studied in many plants but has not been reported in potatoes, the world's fourth-largest food crop. This study identified eight StGPXL genes in potatoes for the first time through genome-wide bioinformatics analysis and further studied the expression patterns of these genes using qRT-PCR. The results showed that the expression of StGPXL1 was significantly upregulated under high-temperature stress, indicating its involvement in potato defense against high-temperature stress, while the expression levels of StGPXL4 and StGPXL5 were significantly downregulated. The expression of StGPXL1, StGPXL2, StGPXL3, and StGPXL6 was significantly upregulated under drought stress, indicating their involvement in potato defense against drought stress. After MeJA hormone treatment, the expression level of StGPXL6 was significantly upregulated, indicating its involvement in the chemical defense mechanism of potatoes. The expression of all StGPXL genes is inhibited under biotic stress, which indicates that GPXL is a multifunctional gene family, which may endow plants with resistance to various stresses. This study will help deepen the understanding of the function of the potato GPXL gene family, provide comprehensive information for the further analysis of the molecular function of the potato GPXL gene family as well as a theoretical basis for potato molecular breeding.

Tomato early blight is a significant disease that causes substantial losses to tomato yield and quality. Mefentrifluconazole, an isopropanol-azole subgroup of triazole fungicides, has been registered in China for controlling various plant diseases, including tomato early blight, grape anthracnose, and apple brown spot. However, limited information is available on the mefentrifluconazole resistance risk and mechanism in plant pathogens. The sensitivity to mefentrifluconazole of 122 isolates of Alternaria alternata, one of the causal agents of tomato early blight, collected from different provinces in China, was evaluated. The results showed a unimodal curve for the sensitivity frequency, with an average EC50 of 0.306 μg/mL. Through fungicide adaption, six resistant mutants (N4, N5, T4, T5, NG1, and NG10) were obtained from three parental isolates, with a mutation frequency of 3.28×10-4 and resistance factors ranging between 19 and 147. The survival fitness of the resistant mutants, except for NG1, was significantly lower than that of their parental isolates. Positive cross-resistance was observed between mefentrifluconazole and difenoconazole or fenbuconazole, whereas no cross-resistance was found with three non-DMI fungicides. Furthermore, three distinct point mutations were detected in the AaCYP51 protein of the resistant mutants: I300S in T4 and T5; A303T in N4, NG1, and NG10; and A303V in N5. Compared to the parental isolates, the AaCYP51 gene was overexpressed in all six resistant mutants when treated with mefentrifluconazole. In summary, the resistance risk of A. alternata to mefentrifluconazole was low, and point mutations and overexpression of the AaCYP51 gene were identified as contributing factors to mefentrifluconazole resistance in A. alternata.

BackgroundOxathiapiprolin, an oxysterol-binding protein inhibitor (OSBPI), shows unexceptionable inhibitory activity against plant pathogenic oomycetes. FRAC (Fungicide Resistance Action Committee) classifies it into the mode of action group F9 (lipid homeostasis and transfer/storage), but very little is known about the lipid metabolism of oomycete pathogens when subjected to oxathiapiprolin. ResultsIn this study, seven lipid categories and 1435 lipid molecules were identified in Phytophthora sojae, among which glycerolipids, glycerophospholipids, and sphingolipids account for 30.10%, 50.59%, and 7.28%, respectively. These lipids were categorized into 31 subclasses, which varied to different extents when treated with oxathiapiprolin. A total of 11 lipid subclasses showed significant changes. Among them, 10 lipid subclasses, lysophosphatidylcholine (LPC), lysophosphatidylethanolamine (LPE), phosphatidylcholine (PC), phosphatidylserine (PS), ceramide (Cer), triglyceride (TG), (o-acyl)-1-hydroxy fatty acid, diglycosylceramide, sphingoshine (So), and sitosterol ester, were significantly up-regulated, while digalactosyldiacylglycerol was the only lipid that was significantly down-regulated by a factor of almost three. These lipid molecules were further analyzed at the lipid species level. A total of 542 species were significantly altered when treated with oxathiapiprolin, including 212 glycerolipids [186 TG and 26 diglycerides (DG)], 167 glycerophospholipids (38 PC, 15 LPC, 19 LPE, seven PS, etc.), 156 sphingolipids (146 Cer, four So, etc.), and some other lipid molecules. Finally, from the orthogonal partial least-squares discrimination analysis model, variable importance for the projection score analysis showed that Cer, TG, and some glycerophospholipids contribute to the metabolic disorder when subjected to oxathiapiprolin. ConclusionGlycerolipids, glycerophospholipids, and sphingolipids in P. sojae undergo significant changes with oxathiapiprolin treatment. These results provided valuable information for further understanding the function of the target protein and the mode of action of OSBPIs in oomycetes. (c) 2022 Society of Chemical Industry.