Biological and molecular characterization of pydiflumetofen and phenamacril dual-resistant Fusarium graminearum strains.

BACKGROUND: Fusarium head blight (FHB) caused by Fusarium graminearum species complex (FGSG) remains a major challenge to cereal crops and resistance to key fungicides by the pathogen threatens control efficacy. Pydiflumetofen, a succinate dehydrogenase inhibitor, and phenamacril, a cyanoacrylate fungicide targeting myosin I, have been applied to combat this disease. Nonetheless, emergence of pydiflumetofen resistance in a subset of field isolates alongside laboratory-induced facile generation of phenamacril-resistant isolates signals a critical danger of resistance proliferation. RESULTS: Our study investigates the development of dual resistance to these fungicides in F. graminearum. Utilizing pydiflumetofen-resistant (PyR) and -sensitive (PyS) isolates, we obtained dual-resistant (PyRPhR) and phenamacril-resistant (PySPhR) mutants on potato sucrose agar containing phenamacril. Mutation rates for phenamacril resistance were comparable between pydiflumetofen-resistant and -sensitive isolates, implying independent pathways for resistance development. The mutants compromised in fungal growth, competitive viability and deoxynivalenol production, suggesting fitness penalties for the dual-resistant mutants. However, no cross-resistance was found with tebuconazole or fludioxonil. In addition, we characterized four critical amino acid changes (S217L, C423R, K537T, E420G) in the Myo1 that were verified to confer phenamacril resistance in F. graminearum. CONCLUSION: This research indicates the possibility of resistance development for both pydiflumetofen and phenamacril in F. graminearum and emphasizes the need for fungicide resistance management for FHB. © 2024 Society of Chemical Industry.

Small holes, big impact: Stomata in plant-pathogen-climate epic trifecta.

The regulation of stomatal aperture opening and closure represents an evolutionary battle between plants and pathogens, characterized by adaptive strategies that influence both plant resistance and pathogen virulence. The ongoing climate change introduces further complexity, affecting pathogen invasion and host immunity. This review delves into recent advances on our understanding of the mechanisms governing immunity-related stomatal movement and patterning with an emphasis on the regulation of stomatal opening and closure dynamics by pathogen patterns and host phytocytokines. In addition, the review explores how climate changes impact plant-pathogen interactions by modulating stomatal behavior. In light of the pressing challenges associated with food security and the unpredictable nature of climate changes, future research in this field, which includes the investigation of spatiotemporal regulation and engineering of stomatal immunity, emerges as a promising avenue for enhancing crop resilience and contributing to climate control strategies.

Translation of nanotechnology-based implants for orthopedic applications: current barriers and future perspective.

The objective of bioimplant engineering is to develop biologically compatible materials for restoring, preserving, or altering damaged tissues and/or organ functions. The variety of substances used for orthopedic implant applications has been substantially influenced by modern material technology. Therefore, nanomaterials can mimic the surface properties of normal tissues, including surface chemistry, topography, energy, and wettability. Moreover, the new characteristics of nanomaterials promote their application in sustaining the progression of many tissues. The current review establishes a basis for nanotechnology-driven biomaterials by demonstrating the fundamental design problems that influence the success or failure of an orthopedic graft, cell adhesion, proliferation, antimicrobial/antibacterial activity, and differentiation. In this context, extensive research has been conducted on the nano-functionalization of biomaterial surfaces to enhance cell adhesion, differentiation, propagation, and implant population with potent antimicrobial activity. The possible nanomaterials applications (in terms of a functional nanocoating or a nanostructured surface) may resolve a variety of issues (such as bacterial adhesion and corrosion) associated with conventional metallic or non-metallic grafts, primarily for optimizing implant procedures. Future developments in orthopedic biomaterials, such as smart biomaterials, porous structures, and 3D implants, show promise for achieving the necessary characteristics and shape of a stimuli-responsive implant. Ultimately, the major barriers to the commercialization of nanotechnology-derived biomaterials are addressed to help overcome the limitations of current orthopedic biomaterials in terms of critical fundamental factors including cost of therapy, quality, pain relief, and implant life. Despite the recent success of nanotechnology, there are significant hurdles that must be overcome before nanomedicine may be applied to orthopedics. The objective of this review was to provide a thorough examination of recent advancements, their commercialization prospects, as well as the challenges and potential perspectives associated with them. This review aims to assist healthcare providers and researchers in extracting relevant data to develop translational research within the field. In addition, it will assist the readers in comprehending the scope and gaps of nanomedicine's applicability in the orthopedics field.

Recent developments in nanomaterials for upgrading treatment of orthopedics diseases.

Nanotechnology has changed science in the last three decades. Recent applications of nanotechnology in the disciplines of medicine and biology have enhanced medical diagnostics, manufacturing, and drug delivery. The latest studies have demonstrated this modern technology's potential for developing novel methods of disease detection and treatment, particularly in orthopedics. According to recent developments in bone tissue engineering, implantable substances, diagnostics and treatment, and surface adhesives, nanomedicine has revolutionized orthopedics. Numerous nanomaterials with distinctive chemical, physical, and biological properties have been engineered to generate innovative medication delivery methods for the local, sustained, and targeted delivery of drugs with enhanced therapeutic efficacy and minimal or no toxicity, indicating a very promising strategy for effectively controlling illnesses. Extensive study has been carried out on the applications of nanotechnology, particularly in orthopedics. Nanotechnology can revolutionize orthopedics cure, diagnosis, and research. Drug delivery precision employing nanotechnology using gold and liposome nanoparticles has shown especially encouraging results. Moreover, the delivery of drugs and biologics for osteosarcoma is actively investigated. Different kind of biosensors and nanoparticles has been used in the diagnosis of bone disorders, for example, renal osteodystrophy, Paget's disease, and osteoporosis. The major hurdles to the commercialization of nanotechnology-based composite are eventually examined, thus helping in eliminating the limits in connection to some pre-existing biomaterials for orthopedics, important variables like implant life, quality, cure cost, and pain and relief from pain. The potential for nanotechnology in orthopedics is tremendous, and most of it looks to remain unexplored, but not without challenges. This review aims to highlight the up tp date developments in nanotechnology for boosting the treatment modalities for orthopedic ailments. Moreover, we also highlighted unmet requirements and present barriers to the practical adoption of biomimetic nanotechnology-based orthopedic treatments.

The PTI-suppressing Avr2 effector from Fusarium oxysporum suppresses mono-ubiquitination and plasma membrane dissociation of BIK1.

Plant pathogens use effector proteins to target host processes involved in pathogen perception, immune signalling, or defence outputs. Unlike foliar pathogens, it is poorly understood how root-invading pathogens suppress immunity. The Avr2 effector from the tomato root- and xylem-colonizing pathogen Fusarium oxysporum suppresses immune signalling induced by various pathogen-associated molecular patterns (PAMPs). It is unknown how Avr2 targets the immune system. Transgenic AVR2 Arabidopsis thaliana phenocopies mutants in which the pattern recognition receptor (PRR) co-receptor BRI1-ASSOCIATED RECEPTOR KINASE (BAK1) or its downstream signalling kinase BOTRYTIS-INDUCED KINASE 1 (BIK1) are knocked out. We therefore tested whether these kinases are Avr2 targets. Flg22-induced complex formation of the PRR FLAGELLIN SENSITIVE 2 and BAK1 occurred in the presence and absence of Avr2, indicating that Avr2 does not affect BAK1 function or PRR complex formation. Bimolecular fluorescence complementation assays showed that Avr2 and BIK1 co-localize in planta. Although Avr2 did not affect flg22-induced BIK1 phosphorylation, mono-ubiquitination was compromised. Furthermore, Avr2 affected BIK1 abundance and shifted its localization from nucleocytoplasmic to the cell periphery/plasma membrane. Together, these data imply that Avr2 may retain BIK1 at the plasma membrane, thereby suppressing its ability to activate immune signalling. Because mono-ubiquitination of BIK1 is required for its internalization, interference with this process by Avr2 could provide a mechanistic explanation for the compromised BIK1 mobility upon flg22 treatment. The identification of BIK1 as an effector target of a root-invading vascular pathogen identifies this kinase as a conserved signalling component for both root and shoot immunity.

An overview of the material science and knowledge of nanomedicine, bioscaffolds, and tissue engineering for tendon restoration.

Tendon wounds are a worldwide health issue affecting millions of people annually. Due to the characteristics of tendons, their natural restoration is a complicated and lengthy process. With the advancement of bioengineering, biomaterials, and cell biology, a new science, tissue engineering, has developed. In this field, numerous ways have been offered. As increasingly intricate and natural structures resembling tendons are produced, the results are encouraging. This study highlights the nature of the tendon and the standard cures that have thus far been utilized. Then, a comparison is made between the many tendon tissue engineering methodologies proposed to date, concentrating on the ingredients required to gain the structures that enable appropriate tendon renewal: cells, growth factors, scaffolds, and scaffold formation methods. The analysis of all these factors enables a global understanding of the impact of each component employed in tendon restoration, thereby shedding light on potential future approaches involving the creation of novel combinations of materials, cells, designs, and bioactive molecules for the restoration of a functional tendon.

A mini-review on the emerging role of nanotechnology in revolutionizing orthopedic surgery: challenges and the road ahead.

An emerging application of nanotechnology in medicine currently being developed involves employing nanoparticles to deliver drugs, heat, light, or other substances to specific types of cells (such as cancer cells). As most biological molecules exist and function at the nanoscale, engineering and manipulating matter at the molecular level has many advantages in the field of medicine (nanomedicine). Although encouraging, it remains unclear how much of this will ultimately result in improved patient care. In surgical specialties, clinically relevant nanotechnology applications include the creation of surgical instruments, suture materials, imaging, targeted drug therapy, visualization methods, and wound healing techniques. Burn lesion and scar management is an essential nanotechnology application. Prevention, diagnosis, and treatment of numerous orthopedic conditions are crucial technological aspects for patients' functional recovery. Orthopedic surgery is a specialty that deals with the diagnosis and treatment of musculoskeletal disorders. In recent years, the field of orthopedics has been revolutionized by the advent of nanotechnology. Using biomaterials comprised of nanoparticles and structures, it is possible to substantially enhance the efficacy of such interactions through nanoscale material modifications. This serves as the foundation for the majority of orthopedic nanotechnology applications. In orthopedic surgery, nanotechnology has been applied to improve surgical outcomes, enhance bone healing, and reduce complications associated with orthopedic procedures. This mini-review summarizes the present state of nanotechnology in orthopedic surgery, including its applications as well as possible future directions.

Disarm resistance: Fungal effectors target WAK alternative splicing variant for virulence.

Molecular interactions between pathogen effectors and plant immunity underpin the arms race of disease resistance and susceptibility. In a recently published Cell Reports paper, Zuo et al. reported the mechanistic characterization of Fusarium graminearum CFEM effectors that dampen ZmWAK17-mediated defenses in maize (Zea mays).

SUMOylation regulates pre-mRNA splicing to overcome DNA damage in fungi.

Pathogenic fungi are subject to DNA damage stress derived from host immune responses during infection. Small ubiquitin-like modifier (SUMO) modification and precursor (pre)-mRNA splicing are both involved in DNA damage response (DDR). However, the mechanisms of how SUMOylation and splicing coordinated in DDR remain largely unknown. Combining with biochemical analysis, RNA-Seq method, and biological analysis, we report that SUMO pathway participates in DDR and virulence in Fusarium graminearum, a causal agent of Fusarium head blight of cereal crops world-wide. Interestingly, a key transcription factor FgSR is SUMOylated upon DNA damage stress. SUMOylation regulates FgSR nuclear-cytoplasmic partitioning and its phosphorylation by FgMec1, and promotes its interaction with chromatin remodeling complex SWI/SNF for activating the expression of DDR-related genes. Moreover, the SWI/SNF complex was found to further recruit splicing-related NineTeen Complex, subsequently modulates pre-mRNA splicing during DDR. Our findings reveal a novel function of SUMOylation in DDR by regulating a transcription factor to orchestrate gene expression and pre-mRNA splicing to overcome DNA damage during the infection of F. graminearum, which advances the understanding of the delicate regulation of DDR by SUMOylation in pathogenic fungi, and extends the knowledge of cooperation of SUMOylation and pre-mRNA splicing in DDR in eukaryotes.

Phytocytokine signalling reopens stomata in plant immunity and water loss.

Stomata exert considerable effects on global carbon and water cycles by mediating gas exchange and water vapour1,2. Stomatal closure prevents water loss in response to dehydration and limits pathogen entry3,4. However, prolonged stomatal closure reduces photosynthesis and transpiration and creates aqueous apoplasts that promote colonization by pathogens. How plants dynamically regulate stomatal reopening in a changing climate is unclear. Here we show that the secreted peptides SMALL PHYTOCYTOKINES REGULATING DEFENSE AND WATER LOSS (SCREWs) and the cognate receptor kinase PLANT SCREW UNRESPONSIVE RECEPTOR (NUT) counter-regulate phytohormone abscisic acid (ABA)- and microbe-associated molecular pattern (MAMP)-induced stomatal closure. SCREWs sensed by NUT function as immunomodulatory phytocytokines and recruit SOMATIC EMBRYOGENESIS RECEPTOR-LIKE KINASE (SERK) co-receptors to relay immune signalling. SCREWs trigger the NUT-dependent phosphorylation of ABA INSENSITIVE 1 (ABI1) and ABI2, which leads to an increase in the activity of ABI phosphatases towards OPEN STOMATA 1 (OST1)-a key kinase that mediates ABA- and MAMP-induced stomatal closure5,6-and a reduction in the activity of S-type anion channels. After induction by dehydration and pathogen infection, SCREW-NUT signalling promotes apoplastic water loss and disrupts microorganism-rich aqueous habitats to limit pathogen colonization. The SCREW-NUT system is widely distributed across land plants, which suggests that it has an important role in preventing uncontrolled stomatal closure caused by abiotic and biotic stresses to optimize plant fitness.

Isolation of High-Molecular-Weight (HMW ) DNA from Fusarium oxysporum for Long-Read Sequencing.

In many instances Fusarium oxysporum genomes are complex and challenging to assemble mainly due to the increased number of repetitive elements and variable numbers of supernumerary chromosomes, which are primarily associated with pathogenicity. Hence, to obtain the accurate F. oxysporum genome assembly and high-resolution sequence information, protocols for versatile, reliable, and high recovery of high-quality DNA for diverse sequencing platforms are instrumental. Here, we describe two protocols for the isolation of DNA from isolates of F. oxysporum. One is a quick and easy method for high-throughput extraction of DNA to rapidly screen diverse isolates by marker-assisted PCR analysis. Another is to harvest high-quality and high-molecular-weight DNA for whole-genome sequencing. In addition, we also include a library preparation protocol optimized for the third-generation sequencing technology using the portable MinION device to obtain long-read sequences. These protocols can be potentially further applied for all Fusarium spp. and other fungal pathogens, including Verticillium.

The Arabidopsis MIK2 receptor elicits immunity by sensing a conserved signature from phytocytokines and microbes.

Sessile plants encode a large number of small peptides and cell surface-resident receptor kinases, most of which have unknown functions. Here, we report that the Arabidopsis receptor kinase MALE DISCOVERER 1-INTERACTING RECEPTOR-LIKE KINASE 2 (MIK2) recognizes the conserved signature motif of SERINE-RICH ENDOGENOUS PEPTIDEs (SCOOPs) from Brassicaceae plants as well as proteins present in fungal Fusarium spp. and bacterial Comamonadaceae, and elicits various immune responses. SCOOP signature peptides trigger immune responses and altered root development in a MIK2-dependent manner with a sub-nanomolar sensitivity. SCOOP12 directly binds to the extracellular leucine-rich repeat domain of MIK2 in vivo and in vitro, indicating that MIK2 is the receptor of SCOOP peptides. Perception of SCOOP peptides induces the association of MIK2 and the coreceptors SOMATIC EMBRYOGENESIS RECEPTOR KINASE 3 (SERK3) and SERK4 and relays the signaling through the cytosolic receptor-like kinases BOTRYTIS-INDUCED KINASE 1 (BIK1) and AVRPPHB SUSCEPTIBLE1 (PBS1)-LIKE 1 (PBL1). Our study identifies a plant receptor that bears a dual role in sensing the conserved peptide motif from phytocytokines and microbial proteins via a convergent signaling relay to ensure a robust immune response.

Interplay of two transcription factors for recruitment of the chromatin remodeling complex modulates fungal nitrosative stress response.

Nitric oxide (NO) is a diffusible signaling molecule that modulates animal and plant immune responses. In addition, reactive nitrogen species derived from NO can display antimicrobial activities by reacting with microbial cellular components, leading to nitrosative stress (NS) in pathogens. Here, we identify FgAreB as a regulator of the NS response in Fusarium graminearum, a fungal pathogen of cereal crops. FgAreB serves as a pioneer transcription factor for recruitment of the chromatin-remodeling complex SWI/SNF at the promoters of genes involved in the NS response, thus promoting their transcription. FgAreB plays important roles in fungal infection and growth. Furthermore, we show that a transcription repressor (FgIxr1) competes with the SWI/SNF complex for FgAreB binding, and negatively regulates the NS response. NS, in turn, promotes the degradation of FgIxr1, thus enhancing the recruitment of the SWI/SNF complex by FgAreB.

A nonproteinaceous Fusarium cell wall extract triggers receptor-like protein-dependent immune responses in Arabidopsis and cotton.

Fusarium wilt caused by the ascomycete fungus Fusarium oxysporum is a devastating disease of many economically important crops. The mechanisms underlying plant responses to F. oxysporum infections remain largely unknown. We demonstrate here that a water-soluble, heat-resistant and nonproteinaceous F. oxysporum cell wall extract (FoCWE) component from multiple F. oxysporum isolates functions as a race-nonspecific elicitor, also termed pathogen-associated molecular pattern (PAMP). FoCWE triggers several demonstrated immune responses, including mitogen-activated protein (MAP) kinase phosphorylation, reactive oxygen species (ROS) burst, ethylene production, and stomatal closure, in cotton and Arabidopsis. Pretreated FoCWE protects cotton seeds against infections by virulent F. oxysporum f. sp. vasinfectum (Fov), and Arabidopsis plants against the virulent bacterium, Pseudomonas syringae, suggesting the potential application of FoCWEs in crop protection. Host-mediated responses to FoCWE do not appear to require LYKs/CERK1, BAK1 or SOBIR1, which are commonly involved in PAMP perception and/or signalling. However, FoCWE responses and Fusarium resistance in cotton partially require two receptor-like proteins, GhRLP20 and GhRLP31. Transcriptome analysis suggests that FoCWE preferentially activates cell wall-mediated defence, and Fov has evolved virulence mechanisms to suppress FoCWE-induced defence. These findings suggest that FoCWE is a classical PAMP that is potentially recognised by a novel pattern-recognition receptor to regulate cotton resistance to Fusarium infections.

Damage-Associated Molecular Pattern-Triggered Immunity in Plants.

As a universal process in multicellular organisms, including animals and plants, cells usually emit danger signals when suffering from attacks of microbes and herbivores, or physical damage. These signals, termed as damage-associated molecular patterns (DAMPs), mainly include cell wall or extracellular protein fragments, peptides, nucleotides, and amino acids. Once exposed on cell surfaces, DAMPs are detected by plasma membrane-localized receptors of surrounding cells to regulate immune responses against the invading organisms and promote damage repair. DAMPs may also act as long-distance mobile signals to mediate systemic wounding responses. Generation, release, and perception of DAMPs, and signaling events downstream of DAMP perception are all rigorously modulated by plants. These processes integrate together to determine intricate mechanisms of DAMP-triggered immunity in plants. In this review, we present an extensive overview on our current understanding of DAMPs in plant immune system.

A phosphorylated transcription factor regulates sterol biosynthesis in Fusarium graminearum.

Sterol biosynthesis is controlled by transcription factor SREBP in many eukaryotes. Here, we show that SREBP orthologs are not involved in the regulation of sterol biosynthesis in Fusarium graminearum, a fungal pathogen of cereal crops worldwide. Instead, sterol production is controlled in this organism by a different transcription factor, FgSR, that forms a homodimer and binds to a 16-bp cis-element of its target gene promoters containing two conserved CGAA repeat sequences. FgSR is phosphorylated by the MAP kinase FgHog1, and the phosphorylated FgSR interacts with the chromatin remodeling complex SWI/SNF at the target genes, leading to enhanced transcription. Interestingly, FgSR orthologs exist only in Sordariomycetes and Leotiomycetes fungi. Additionally, FgSR controls virulence mainly via modulating deoxynivalenol biosynthesis and responses to phytoalexin.

The Activators of Type 2A Phosphatases (PP2A) Regulate Multiple Cellular Processes Via PP2A-Dependent and -Independent Mechanisms in Fusarium graminearum.

The type 2A protein phosphatases (PP2As) are holoenzymes in all eukaryotes but their activators remain unknown in filamentous fungi. Fusarium graminearum contains three PP2As (FgPp2A, FgSit4, and FgPpg1), which play critical roles in fungal growth, development, and virulence. Here, we identified two PP2A activators (PTPAs), FgRrd1 and FgRrd2, and found that they control PP2A activity in a PP2A-specific manner. FgRrd1 interacts with FgPpg1, but FgRrd2 interacts with FgPp2A and very weakly with FgSit4. Furthermore, FgRrd2 activates FgPp2A via regulating FgPp2A methylation. Phenotypic assays showed that FgRrd1 and FgRrd2 regulate mycelial growth, conidiation, sexual development, and lipid droplet biogenesis. More importantly, both FgRrd1 and FgRrd2 interact with RNA polymerase II, subsequently modulating its enrichments at the promoters of mycotoxin biosynthesis genes, which is independent on PP2A. In addition, FgRrd2 modulates response to phenylpyrrole fungicide, via regulating the phosphorylation of kinase FgHog1 in the high-osmolarity glycerol pathway, and to caffeine, via modulating FgPp2A methylation. Taken together, results of this study indicate that FgRrd1 and FgRrd2 regulate multiple physiological processes via different regulatory mechanisms in F. graminearum, which provides a novel insight into understanding the biological functions of PTPAs in fungi.

The FgSsb-FgZuo-FgSsz complex regulates multiple stress responses and mycotoxin production via folding the soluble SNARE Vam7 and ß2-tubulin in Fusarium graminearum.

Hsp70 proteins play important roles in protein folding in the budding yeast, but their functions in pathogenic fungi are largely unknown. Here, we found that Fusarium graminearum Hsp70 proteins FgSsb, FgSsz and their cochaperone FgZuo formed a complex. This complex was required for microtubule morphology, vacuole fusion and endocytosis. More importantly, the ß2-tubulin FgTub2 and SNARE protein FgVam7 were identified as targeting proteins of this complex. We further found that the complex FgSsb-FgZuo-FgSsz controlled sensitivity of F. graminearum to the antimicrotubule drug carbendazim and cold stress via regulating the folding of FgTub2. Moreover, this complex assisted the folding of FgVam7, subsequently modulated vacuole fusion and responses to heavy metal, osmotic and oxidative stresses. In addition, the deletion of this complex led to dramatically decreased deoxynivalenol biosynthesis. This study uncovers a novel regulating mechanism of Hsp70 in multiple stress responses in a filamentous fungus.

Combined application of diclofenac and celecoxib with an opioid yields superior efficacy in metastatic bone cancer pain: a randomized controlled trial.

BACKGROUND: Metastatic bone cancer pain is one of the most common clinical cancer pains and is caused by many factors. This study was conducted to explore the clinical efficacy of using two non-steroidal anti-inflammatory drugs (NSAIDs) along with an opioid in treating metastatic bone cancer pain. MATERIAL AND METHOD: A total of 342 patients with a pain score of 7-10 on the visual analog scale (VAS) were recruited for 4 weeks of treatment and randomly assigned to three different groups-one group received two NSAIDs (diclofenac and celecoxib), one group received diclofenac, and one group received celecoxib. All patients received morphine sulfate 10 mg/12 h with a reduction of 50% or addition of 25% each time until the VAS score was <5. The VAS score, remission rate (RR), breakthrough pain (BTP), morphine sulfate dose and side-effects among the three groups were compared. RESULTS: After 4 weeks of treatment, we found that using two NSAIDs along with an opioid could yield a significantly lower VAS score (p = 0.006), higher RR (p = 0.0002) and fewer incidences of BTP (p = 0.011), compared to the use of only one NSAID. Furthermore, using two NSAIDS could significantly decrease the consumption of morphine sulfate compared to using each NSAID in isolation (p = 0.0031 in week 1; p = 0.020 in week 2; p = 0.0012 in week 4). Additionally, using two NSAIDs could produce fewer incidences of dizziness (p = 0.002), constipation (p < 0.0001) and drowsiness (p < 0.0001). CONCLUSION: Although limited by the relatively small samples, these results indicate that using two NSAIDs along with an opioid in treating metastatic bone cancer pain was more effective and acceptable, which is worthy of further clinical application.

The microtubule end-binding protein FgEB1 regulates polar growth and fungicide sensitivity via different interactors in Fusarium graminearum.

In yeasts, the end-binding protein 1 (EB1) homologs regulate microtubule dynamics, cell polarization, and chromosome stability. However, functions of EB1 orthologs in plant pathogenic fungi have not been characterized yet. Here, we observed that the FgEB1 deletion mutant (ΔFgEB1) of Fusarium graminearum exhibits twisted hyphae, increased hyphal branching and curved conidia, indicating that FgEB1 is involved in the regulation of cellular polarity. Microscopic examination further showed that the microtubules of ΔFgEB1 exhibited less organized in comparison with those of the wild type. In addition, the lack of FgEB1 also altered the distribution of polarity-related class I myosin via the interaction with the actin. On the other hand, we identified four core septins as FgEB1-interacting proteins, and found that FgEB1 and septins regulated conidial polar growth in the opposite orientation. Interestingly, FgEB1 and FgKar9 constituted another complex that modulated the response to carbendazim, a microtubule-damaging agent specifically. In addition, the deletion of FgEB1 led to dramatically decreased deoxynivalenol (DON) biosynthesis. Taken together, results of this study indicate that FgEB1 regulates cellular polarity, fungicide sensitivity and DON biosynthesis via different interactors in F. graminarum, which provides a novel insight into understanding of the biological functions of EB1 in filamentous fungi.