DGARM/C10orf76/ARMH3 for Ceramide Transfer Zone at the Endoplasmic Reticulum-Distal Golgi Contacts.

Phosphatidylinositol 4-monophosphate (PtdIns(4)P) is one of the key membrane components which mark the membrane contact sites. In the mammalian Golgi complex, PtdIns(4)P is produced at various subregions via specific mechanisms for each site. Particularly, PtdIns(4)P pools generated at the distal Golgi regions are pivotal for the determination of membrane contacts between the endoplasmic reticulum (ER) and Golgi, at which inter-organelle lipid transport takes place. In this short review, we will focus on C10orf76 (or ARMH3), which we propose to rename as DGARM after a distal Golgi armadillo repeat protein, for its function in generating a PtdIns(4)P pool crucial for ER-to-distal Golgi ceramide transport. We further discuss from the viewpoint of the evolutionary conservation of DGARM.

The Long-Distance Transport of Some Plant Hormones and Possible Involvement of Lipid-Binding and Transfer Proteins in Hormonal Transport.

Adaptation to changes in the environment depends, in part, on signaling between plant organs to integrate adaptive response at the level of the whole organism. Changes in the delivery of hormones from one organ to another through the vascular system strongly suggest that hormone transport is involved in the transmission of signals over long distances. However, there is evidence that, alternatively, systemic responses may be brought about by other kinds of signals (e.g., hydraulic or electrical) capable of inducing changes in hormone metabolism in distant organs. Long-distance transport of hormones is therefore a matter of debate. This review summarizes arguments for and against the involvement of the long-distance transport of cytokinins in signaling mineral nutrient availability from roots to the shoot. It also assesses the evidence for the role of abscisic acid (ABA) and jasmonates in long-distance signaling of water deficiency and the possibility that Lipid-Binding and Transfer Proteins (LBTPs) facilitate the long-distance transport of hormones. It is assumed that proteins of this type raise the solubility of hydrophobic substances such as ABA and jasmonates in hydrophilic spaces, thereby enabling their movement in solution throughout the plant. This review collates evidence that LBTPs bind to cytokinins, ABA, and jasmonates and that cytokinins, ABA, and LBTPs are present in xylem and phloem sap and co-localize at sites of loading into vascular tissues and at sites of unloading from the phloem. The available evidence indicates a functional interaction between LBTPs and these hormones.

Orthogonal Targeting of SAC1 to Mitochondria Implicates ORP2 as a Major Player in PM PI4P Turnover.

Oxysterol-binding protein (OSBP)-related proteins (ORPs) 5 and 8 have been shown to deplete the lipid phosphatidylinositol 4-phosphate (PI4P) at sites of membrane contact between the endoplasmic reticulum (ER) and plasma membrane (PM). This is believed to be caused by transport of PI4P from the PM to the ER, where PI4P is degraded by an ER-localized SAC1 phosphatase. This is proposed to power the anti-port of phosphatidylserine (PS) lipids from ER to PM, up their concentration gradient. Alternatively, ORPs have been proposed to sequester PI4P, dependent on the concentration of their alternative lipid ligand. Here, we aimed to distinguish these possibilities in living cells by orthogonal targeting of PI4P transfer and degradation to PM-mitochondria contact sites. Surprisingly, we found that orthogonal targeting of SAC1 to mitochondria enhanced PM PI4P turnover independent of targeting to contact sites with the PM. This turnover could be slowed by knock-down of soluble ORP2, which also has a major impact on PM PI4P levels even without SAC1 over-expression. The data reveal a role for contact site-independent modulation of PM PI4P levels and lipid antiport.

OSBP is a Major Determinant of Golgi Phosphatidylinositol 4-Phosphate Homeostasis.

The lipid phosphatidylinositol 4-phosphate (PI4P) plays a master regulatory role at Golgi membranes, orchestrating membrane budding, non-vesicular lipid transport and membrane organization. It follows that harmonious Golgi function requires strictly maintained PI4P homeostasis. One of the most abundant PI4P effector proteins is the oxysterol binding protein (OSBP), a lipid transfer protein that exchanges trans-Golgi PI4P for ER cholesterol. Although this protein consumes PI4P as part of its lipid anti-porter function, whether it actively contributes to Golgi PI4P homeostasis has been questioned. Here, we employed a series of acute and chronic genetic manipulations, together with orthogonal targeting of OSBP, to interrogate its control over Golgi PI4P abundance. Modulating OSBP levels at ER:Golgi membrane contact sites produces reciprocal changes in PI4P levels. Additionally, we observe that OSBP has a high capacity for PI4P turnover, even at orthogonal organelle membranes. However, despite also visiting the plasma membrane, endogenous OSBP makes no impact on PI4P levels in this compartment. We conclude that OSBP is a major determinant of Golgi PI4P homeostasis.

OSBP is a major determinant of Golgi phosphatidylinositol 4-phosphate homeostasis.

The lipid phosphatidylinositol 4-phosphate (PI4P) plays a master regulatory role at Golgi membranes, orchestrating membrane budding, non-vesicular lipid transport and membrane organization. It follows that harmonious Golgi function requires strictly maintained PI4P homeostasis. One of the most abundant PI4P effector proteins is the oxysterol binding protein (OSBP), a lipid transfer protein that exchanges trans Golgi PI4P for ER cholesterol. Although this protein consumes PI4P as part of its lipid anti-porter function, whether it actively contributes to Golgi PI4P homeostasis has been questioned. Here, we employed a series of acute and chronic genetic manipulations, together with orthogonal targeting of OSBP, to interrogate its control over Golgi PI4P abundance. Modulating OSBP levels at ER:Golgi membrane contact sites produces reciprocal changes in PI4P levels. Additionally, we observe that OSBP has a high capacity for PI4P turnover, even at orthogonal organelle membranes. However, despite also visiting the plasma membrane, endogenous OSBP makes no impact on PI4P levels in this compartment. We conclude that OSBP is a major determinant of Golgi PI4P homeostasis.

The expanding roles of PI4P and PI(4,5)P2 at the plasma membrane: Role of phosphatidylinositol transfer proteins.

Phosphoinositides are phosphorylated derivatives of phosphatidylinositol, a phospholipid that is synthesised at the endoplasmic reticulum. The plasma membrane contains the enzymes to phosphorylate phosphatidylinositol and is therefore rich in the phosphorylated derivatives, PI4P and PI(4,5)P2. PI(4,5)P2 is a substrate for phospholipase C and during cell signaling, PI(4,5)P2 levels are reduced. Here I discuss a family of proteins, phosphatidylinositol transfer proteins (PITPs) that can restore PI(4,5)P2 levels.

Orthogonal targeting of SAC1 to mitochondria implicates ORP2 as a major player in PM PI4P turnover.

Oxysterol binding protein (OSBP)-related proteins (ORPs) 5 and 8 have been shown to deplete the lipid phosphatidylinositol 4-phosphate (PI4P) at sites of membrane contact between the endoplasmic reticulum (ER) and plasma membrane (PM). This is believed to be caused by transport of PI4P from the PM to the ER, where PI4P is degraded by an ER-localized SAC1 phosphatase. This is proposed to power the anti-port of phosphatidylserine (PS) lipids from ER to PM, up their concentration gradient. Alternatively, ORPs have been proposed to sequester PI4P, dependent on the concentration of their alternative lipid ligand. Here, we aimed to distinguish these possibilities in living cells by orthogonal targeting of PI4P transfer and degradation to PM-mitochondria contact sites. Surprisingly, we found that orthogonal targeting of SAC1 to mitochondria enhanced PM PI4P turnover independent of targeting to contact sites with the PM. This turnover could be slowed by knock-down of soluble ORP2, which also has a major impact on PM PI4P levels even without SAC1 over-expression. The data reveal a role for contact site-independent modulation of PM PI4P levels and lipid antiport.

Proceedings of the Eleventh International Meeting on Neuroacanthocytosis Syndromes.

The 11th International Meeting on Neuroacanthocytosis Syndromes was held on September 15th-17th, 2023 at the University Hospital Campus in Homburg/Saar, Germany. The meeting followed the previous ten international symposia, the last of which was held online due to restrictions due to COVID19, in March 2021. The setting of the meeting encouraged interactions, exchange of ideas, and networking opportunities among the participants from around the globe, including basic and clinical scientists, clinicians, and especially patients, their relatives and caregivers. A total of about 20 oral communications were presented in five scientific sessions accompanied by a keynote lecture, a "Poster-Blitz" session, the "Glenn Irvine Prize" lecture and a panel discussion about "Patient registries, international cooperation & future perspectives". In summary, attendees discussed recent advances and set the basis for the next steps, action points, and future studies in close collaboration with the patient associations, which were actively involved in the whole process.

TMEM241 is a UDP-N-acetylglucosamine transporter required for M6P modification of NPC2 and cholesterol transport.

Accurate intracellular cholesterol traffic plays crucial roles. Niemann Pick type C (NPC) proteins NPC1 and NPC2, are two lysosomal cholesterol transporters that mediate the cholesterol exit from lysosomes. However, other proteins involved in this process remain poorly defined. Here, we find that the previously unannotated protein TMEM241 is required for cholesterol egressing from lysosomes through amphotericin B-based genome-wide CRISPR-Cas9 KO screening. Ablation of TMEM241 caused impaired sorting of NPC2, a protein utilizes the mannose-6-phosphate (M6P) modification for lysosomal targeting, resulting in cholesterol accumulation in the lysosomes. TMEM241 is a member of solute transporters 35 nucleotide sugar transporters family and localizes on the cis-Golgi network. Our data indicate that TMEM241 transports UDP-N-acetylglucosamine (UDP-GlcNAc) into Golgi lumen and UDP-GlcNAc is used for the M6P modification of proteins including NPC2. Furthermore, Tmem241-deficient mice display cholesterol accumulation in pulmonary cells and behave pulmonary injury and hypokinesia. Taken together, we demonstrate that TMEM241 is a Golgi-localized UDP-GlcNAc transporter and loss of TMEM241 causes cholesterol accumulation in lysosomes because of the impaired M6P-dependent lysosomal targeting of NPC2.

Apoplastic and Symplasmic Markers of Somatic Embryogenesis.

Somatic embryogenesis (SE) is a process that scientists have been trying to understand for many years because, on the one hand, it is a manifestation of the totipotency of plant cells, so it enables the study of the mechanisms regulating this process, and, on the other hand, it is an important method of plant propagation. Using SE in basic research and in practice is invaluable. This article describes the latest, but also historical, information on changes in the chemical composition of the cell wall during the transition of cells from the somatic to embryogenic state, and the importance of symplasmic communication during SE. Among wall chemical components, different pectic, AGP, extensin epitopes, and lipid transfer proteins have been discussed as potential apoplastic markers of explant cells during the acquisition of embryogenic competence. The role of symplasmic communication/isolation during SE has also been discussed, paying particular attention to the formation of symplasmic domains within and between cells that carry out different developmental processes. Information about the number and functionality of plasmodesmata (PD) and callose deposition as the main player in symplasmic isolation has also been presented.

A comprehensive investigation of lipid-transfer proteins from Cicer arietinum disentangles their role in plant defense against Helicoverpa armigera-infestation.

Lipid Transfer Proteins (LTPs) play a crucial role in synthesizing lipid barrier polymers and are involved in defense signaling during pest and pathogen attacks. Although LTPs are conserved with multifaceted roles in plants, these are not yet identified and characterized in Cicer arietinum. In this study, a genome-wide analysis of LTPs was executed and their physiochemical properties, biochemical function, gene structure analysis, chromosomal localization, promoter analysis, gene duplication, and evolutionary analysis were performed using in silico tools. Furthermore, tissue-specific expression analysis and gene expression analysis during pest attack was also conducted for the LTPs. A total of 48 LTPs were identified and named as CaLTPs. They were predicted to be small unstable proteins with "Glycolipid transfer protein" and "Alpha-Amylase Inhibitors, Lipid Transfer and Seed Storage" domains, that are translocated to the extracellular region. CaLTPs were predicted to possess 3-4 introns and were located on all the eight chromosomes of chickpea with half of the CaLTPs being localized on chromosomes 4, 5, and 6, and found to be closely related to LTPs of Arabidopsis thaliana and Medicago trancatula. Gene duplication and synteny analysis revealed that most of the CaLTPs have evolved due to tandem or segmental gene duplication and were subjected to purifying selection during evolution. The promoters of CaLTPs had development-related, phytohormone-responsive, and abiotic and biotic stress-related cis-acting elements. A few CaLTP transcripts exhibited differential expression in diverse tissue types, while others showed no/very low expression. Out of 20 jasmonate-regulated CaLTPs, 14 exhibited differential expression patterns during Helicoverpa armigera-infestation, indicating their role in plant defense response. This study identified and characterized CaLTPs from an important legume, C. arietinum, and indicated their involvement in plant defense against H. armigera-infestation, which can be further utilized to explore lipid signaling during plant-pest interaction and pest management.

Different tether proteins of the same membrane contact site affect the localization and mobility of each other.

Membrane contact sites enable the exchange of metabolites between subcellular compartments and regulate organelle dynamics and positioning. These structures often contain multiple proteins that tether the membranes, establishing the apposition and functionalizing the structure. In this work, we used drug-inducible tethers in vivo in Saccharomyces cerevisiae to address how different tethers influence each other. We found that the establishment of a region of membrane proximity can recruit tethers, influencing their distribution between different locations or protein complexes. In addition, restricting the localization of one tether to a subdomain of an organelle caused other tethers to be restricted there. Finally, we show that the mobility of contact site tethers can also be influenced by other tethers of the same interface. Overall, our results show that the presence of other tethers at contact sites is an important determinant of the behavior of tethering proteins. This suggests that contact sites with multiple tethers are controlled by the interplay between specific molecular interactions and the cross-influence of tethers of the same interface.

A synthetic glycodendropeptide induces methylation changes on regulatory T cells linked to tolerant responses in anaphylactic-mice.

Introduction: Lipid transfer proteins (LTPs) are allergens found in a wide range of plant-foods. Specifically, Pru p 3, the major allergen of peach, is commonly responsible for severe allergic reactions. The need for new alternatives to conventional food allergy treatments, like restrictive diets, suggests allergen immunotherapy as a promising option. It has been demonstrated that sublingual immunotherapy (SLIT) with synthetic glycodendropeptides, such as D1ManPrup3, containing mannose and Pru p 3 peptides induced tolerance in mice and that the persistence of this effect depends on treatment dose (2nM or 5nM). Moreover, it produces changes associated with differential gene expression and methylation profile of dendritic cells, as well as phenotypical changes in regulatory T cells (Treg). However, there are no works addressing the study of epigenetic changes in terms of methylation in the cell subsets that sustain tolerant responses, Treg. Therefore, in this work, DNA methylation changes in splenic-Treg from Pru p 3 anaphylactic mice were evaluated. Methods: It was performed by whole genome bisulphite sequencing comparing SLIT-D1ManPrup3 treated mice: tolerant (2nM D1ManPrup3), desensitized (5nM D1ManPrup3), and sensitized but not treated (antigen-only), with anaphylactic mice. Results: Most of the methylation changes were found in the gene promoters from both SLIT-treated groups, desensitized (1,580) and tolerant (1,576), followed by the antigen-only (1,151) group. Although tolerant and desensitized mice showed a similar number of methylation changes, only 445 genes were shared in both. Remarkably, interesting methylation changes were observed on the promoter regions of critical transcription factors for Treg function like Stat4, Stat5a, Stat5b, Foxp3, and Gata3. In fact, Foxp3 was observed exclusively as hypomethylated in tolerant group, whereas Gata3 was only hypomethylated in the desensitized mice. Discussion: In conclusion, diverse D1ManPrup3 doses induce different responses (tolerance or desensitization) in mice, which are reflected by differential methylation changes in Tregs.

Evolution of laboratory parameters in patients with lipid transfer protein syndrome after 3 years of immunotherapy.

Lipid transfer protein (LTP) syndrome is an increasingly prevailing disease, especially in the young population, with severely affected quality of life. Since 2013, a specific treatment, called sublingual immunotherapy (SLIT), with peach extract (SLIT-peach®) has been used, but with no long-term effectiveness studies. The main objective of the present study was to assess the long-term effectiveness of SLIT-peach® and to relate the clinical evolution of patients. This was an ambispective study conducted for 3 years. A total of 25 patients with LTP syndrome were selected and treated with SLIT-peach®. They underwent a provocation test in the first year with reintroduced foods that had produced symptoms in the past. Analytical determination of specific immunoglobulin E (IgE) and immunoglobulin G4 (IgG4) to peach (Pru p 3) was performed at the beginning of treatment, at the first year of initiation, and at the end of treatment. These data were compared with the control group comprising 14 patients with LTP syndrome without treatment. A statistically significant decrease in specific IgE to Pru p 3 at the end of the treatment and an increase in specific IgG4 to Pru p 3 1 year after treatment initiation were observed in the active group in relation to tolerance to foods with LTPs. These results indicate that food tolerance begins after the first year and is maintained after the end of 3 years of treatment. In conclusion, treatment with SLIT-peach® for 3 years is effective for patients with LTP syndrome, preventing the evolution of the disease, allowing patients to restart a diet with plant foods, and improving their quality of life.

Sequence Analysis and Biochemical Characteristics of Two Non-specific Lipid Transfer Proteins from Tartary Buckwheat Seeds.

INTRODUCTION: Plant non-specific lipid transfer proteins (nsLTPs) play an important role in plant resistance to various stresses, and show potential applications in agriculture, industrial manufacturing, and medicine. In addition, as more and more nsLTPs are identified as allergens, nsLTPs have attracted interest due to their allergenicity. Two nsLTPs from Tartary buckwheat have been isolated and identified. There is a need to study their biochemical characteristics and allergenicity. OBJECTIVE: The study aims to investigate the biochemical characteristics of two nsLTPs from Tartary buckwheat seeds and evaluate their potential allergenicity. METHODS: Two nsLTPs derived from Tartary buckwheat, namely FtLTP1a and FtLTP1b, were produced by gene cloning, expression, and purification. Sequence analysis and biochemical characteristics of the proteins, including lipid binding ability, α-amylase inhibition activity, antifungal activity, and allergenic activity, were investigated. RESULTS: High-purity recombinant FtLTP1a and FtLTP1b were obtained. FtLTP1a and FtLTP1b exhibited similar lipid binding and antifungal properties. Only FtLTP1b showed weak inhibitory activity against α-amylase. CONCLUSION: FtLTP1b could specifically bind IgE in the serum allergic to buckwheat and cross-react with pollen (w6). FtLTP1b is a novel allergenic member of the lipid-transfer protein 1 family found in Tartary buckwheat.

Non-specific LIPID TRANSFER PROTEIN 1 enhances immunity against tobacco mosaic virus in Nicotiana benthamiana.

Plant non-specific lipid transfer proteins (nsLTPs) are small, cysteine-rich proteins that play significant roles in biotic and abiotic stress responses; however, the molecular mechanism of their functions against viral infections remains unclear. In this study, we employed virus-induced gene-silencing and transgenic overexpression to functionally analyse a type-I nsLTP in Nicotiana benthamiana, NbLTP1, in the immunity response against tobacco mosaic virus (TMV). NbLTP1 was inducible by TMV infection, and its silencing increased TMV-induced oxidative damage and the production of reactive oxygen species (ROS), compromised local and systemic resistance to TMV, and inactivated the biosynthesis of salicylic acid (SA) and its downstream signaling pathway. The effects of NbLTP1-silencing were partially restored by application of exogenous SA. Overexpressing NbLTP1 activated genes related to ROS scavenging to increase cell membrane stability and maintain redox homeostasis, confirming that an early ROS burst followed by ROS suppression at the later phases of pathogenesis is essential for resistance to TMV infection. The cell-wall localization of NbLTP1 was beneficial to viral resistance. Overall, our results showed that NbLTP1 positively regulates plant immunity against viral infection through up-regulating SA biosynthesis and its downstream signaling component, NONEXPRESSOR OF PATHOGENESIS-RELATED 1 (NPR1), which in turn activates pathogenesis-related genes, and by suppressing ROS accumulation at the later phases of viral pathogenesis.

Diversity of Cationic Antimicrobial Peptides in Black Cumin (Nigella sativa L.) Seeds.

Black cumin (Nigella sativa L.) is known to possess a wide variety of antimicrobial peptides belonging to different structural families. Three novel antimicrobial peptides have been isolated from black cumin seeds. Two of them were attributed as members of the non-specific lipid transfer proteins family, and one as a defensin. We have made an attempt of using the proteomic approach for novel antimicrobial peptides search in N. sativa seeds as well. The use of a well-established approach that includes extraction and fractionation stages remains relevant even in the case of novel peptides search because of the lacking N. sativa genome data. Novel peptides demonstrate a spectrum of antimicrobial activity against plant pathogenic organisms that may cause economically important crop diseases. These results obtained allow considering these molecules as candidates to be applied in "next-generation" biopesticides development for agricultural use.

Improving In Vitro Detection of Sensitization to Lipid Transfer Proteins: A New Molecular Multiplex IgE Assay.

SCOPE: LTP-syndrome is characterized by sensitization (IgE) to multiple non-specific lipid transfer proteins (nsLTPs) with a variable clinical outcome. The treatment is primarily based on offending food avoidance. However, the determination of Pru p 3-specific IgE is currently the main diagnostic tool to assess sensitization to nsLTPs. Herein, the study evaluates improvement of LTP-syndrome diagnosis and clinical management using a new IgE multiplex-immunoblot assay with a high diversity of food nsLTPs. METHODS AND RESULTS: An EUROLINE-LTP strip with 28 recombinant nsLTPs from 18 allergenic sources is designed. In total the study investigates 38 patients with LTP-syndrome and compares results from the nsLTPs (LTP-strip) with the respective food extracts of Prick-by-prick (PbP) testing. The agreement exceeds 70% for most nsLTPs, e.g., Pru p 3 (100%), Mal d 3 (97%), Pru av 3 (89%), Pha v 3 isoforms (87%/84%), Ara h 9 (82%), Cor a 8 (82%), and Jug r 3 (82%). The functionality and allergenic relevance of nine recombinant nsLTPs are proven by Basophil activation testing (BAT). CONCLUSIONS: The new IgE multiplex-immunoblot nsLTP assay shows a good diagnostic performance allowing culprit food assessment. Negative results from LTP-strip may indicate potentially tolerable foods, improving diet intervention and patients' quality of life.

EAACI Molecular Allergology User's Guide 2.0.

Since the discovery of immunoglobulin E (IgE) as a mediator of allergic diseases in 1967, our knowledge about the immunological mechanisms of IgE-mediated allergies has remarkably increased. In addition to understanding the immune response and clinical symptoms, allergy diagnosis and management depend strongly on the precise identification of the elicitors of the IgE-mediated allergic reaction. In the past four decades, innovations in bioscience and technology have facilitated the identification and production of well-defined, highly pure molecules for component-resolved diagnosis (CRD), allowing a personalized diagnosis and management of the allergic disease for individual patients. The first edition of the "EAACI Molecular Allergology User's Guide" (MAUG) in 2016 rapidly became a key reference for clinicians, scientists, and interested readers with a background in allergology, immunology, biology, and medicine. Nevertheless, the field of molecular allergology is moving fast, and after 6 years, a new EAACI Taskforce was established to provide an updated document. The Molecular Allergology User's Guide 2.0 summarizes state-of-the-art information on allergen molecules, their clinical relevance, and their application in diagnostic algorithms for clinical practice. It is designed for both, clinicians and scientists, guiding health care professionals through the overwhelming list of different allergen molecules available for testing. Further, it provides diagnostic algorithms on the clinical relevance of allergenic molecules and gives an overview of their biology, the basic mechanisms of test formats, and the application of tests to measure allergen exposure.

A non-specific lipid transfer protein, NtLTPI.38, positively mediates heat tolerance by regulating photosynthetic ability and antioxidant capacity in tobacco.

Non-specific lipid transfer proteins (nsLTPs) play an important role in plant growth and stress resistance; however, their function in tobacco remains poorly understood. Therefore, to explore the function of NtLTP in response to high temperature, we identified an NtLTPI.38 from tobacco, obtained its overexpression and knockout transgenic plants, and further studied their response to heat stress (42 °C). The results showed that NtLTPI.38 overexpression in tobacco reduced chlorophyll degradation, alleviated the high temperature damage to photosynthetic organs, and enhanced the photosynthetic capacity of tobacco under heat stress. NtLTPI.38 overexpression in heat-stressed tobacco increased the contents of soluble sugar and protein, proline, and flavonoid substances, reduced the relative conductivity, and decreased H2O2, O2•-, and MDA accumulation, and increased the enzymatic antioxidant activities, such as superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX), compared to wild type (WT) and knockout mutant plants. RT-PCR confirmed that the expression levels of antioxidant enzymes and thermal stress-related genes were significantly upregulated under thermal stress in overexpression plants. Therefore, NtLTPI.38 enhanced heat tolerance in tobacco by mitigating photosynthetic damage and improving osmoregulation and antioxidant capacity. These results provided the theoretical basis and a potential resource for further breeding projects to improve heat tolerance in plants.