Fungal Pathogens Research Articles

From Spear to Shield: A Novel Antifungal Drug that Safely Enhances Rice Immune Defenses.

The infection and resistance of pathogenic fungi pose a significant threat to food crop safety, highlighting the urgent need for new green antifungal agents. Fusarium acid (FA) with its simple and novel structure correlates with the principles of green pesticides and has demonstrated substantial broad-spectrum antifungal activity. In a previous study, several promising lead compounds were identified. This study focused on further optimizing lead compound A1. Its inhibitory effect was evaluated against six different pathogenic fungi and several new promising compounds were identified. Notably, the anti-Magnaporthe oryzae (M. oryzae) activity of compound B4 was significantly enhanced with an EC50 value of 910 ng/mL. Rice safety tests indicated that B4 not only exhibited no adverse effect on rice growth and chlorophyll synthesis but also induced plant immunity by increasing the levels of polyphenol oxidase (PPO), peroxidase (POD), and superoxide dismutase (SOD), and soluble sugars. Further investigations into the antifungal mechanism of B4 indicated that it enhanced the permeability and damage of the mycelial membrane, thereby leading to electrolyte leakage and the loss of essential cellular substances. Subsequently, B4 induced the production of reactive oxygen species (ROS) in M. oryzae cell, including •OH, •O2-, and 1O2, while promoting increased levels of malondialdehyde (MDA) and SOD enzyme activity. Rice infection tests indicated that B4 effectively inhibited M. oryzae conidia activity and inhibited melanin production. These findings indicated that FA derivatives hold significant potential as a new strategy for M. oryzae disease management and offer valuable insights for the control of plant fungal diseases.

Fluazinam Resistance in Colletotrichum gloeosporioides and Its Association with Metabolic Detoxification and Efflux.

Colletotrichum gloeosporioides is a major pathogen causing anthracnose of pepper (Capsicum annuum). In agricultural production, it is typically managed using fungicides like fluazinam. However, the frequent use of fungicides raises concerns about the potential development of fungicide resistance. This issue has not been extensively documented. To address this, 102 isolates of C. gloeosporioides were collected from pepper in fields. The EC50 values of these isolates to fluazinam exhibited a unimodal distribution with a mean value of 0.18 ± 0.14 μg/mL, indicating the absence of naturally occurring resistance in the sampling region. Through fluazinam domestication, 35 fluazinam-resistant mutants were obtained from the parental strain Cg219. These mutants exhibited strong cross-resistance to the fungicide SYP-14288. Metabolic analysis revealed that C. gloeosporioides could metabolize fluazinam into compounds lacking antifungal activity. Genetic analysis showed that genes related to efflux and detoxification were upregulated to varying degrees in both fluazinam-resistant mutants and fluazinam-treated strains. By comparing fungal growth and pathogenicity between the mutants and their parent, the mutants showed impaired overall fitness. Therefore, C. gloeosporioides has a low risk of developing resistance to fluazinam. This study provides critical data for monitoring the emergence of fungicide resistance and developing resistance management strategies for fluazinam.

Exploring Fungal Abundance and WHO Fungal Priority Pathogens in Agricultural Fields: A One Health Perspective in Northeast Thailand

Exploring Fungal Abundance and WHO Fungal Priority Pathogens in Agricultural Fields: A One Health Perspective in Northeast Thailand

Development of a UVC application machine for managing plant diseases in soilless greenhouse crop production

This study aimed to develop a UVC machine designed for the treatment of common fungal, bacterial, and viral diseases in greenhouse-grown crops, serving as an alternative to chemical applications. The machine utilizes standard battery carts or trolley infrastructure for mobility along heating pipes in greenhouses. The machine is equipped with 8 UVC lamps, four on each side, each having a power of 145 W and a length of 1.5 m, complete with reflectors. The lamps can be adjusted both vertically and horizontally to optimize their positioning based on the crop conditions. Two 24 V switches control the lamp power levels according to data received from the microcontroller. Each lamp can be controlled via software, allowing them to be turned on or off as needed. The lamps on either side of the machine can be operated independently to provide the specific dosage required for treating plant diseases within a range of 5 to 100 mJ/cm2. UVC doses were measured at various machine speeds and lamp-sensor distances. Statistical analyses confirmed a significant effect of PWM speed on UVC dose (p < 0.05), demonstrating the inverse relationship between machine speed and accumulated UVC exposure. The UVC machine has proven effective as an autonomous device for crop disease management. Operating the lamps at slower speeds increases the dosage but may delay treatment, which is critical for stopping the spread of diseases or pests.

Rapid diagnosis of Diaporthe helianthi in sunflower using RPA/CRISPR-Cas12 and lateral flow assay

Diaporthe helianthi is one of the main fungal pathogens responsible for causing phomopsis stem canker and significant yield losses of sunflowers. In this study, the calmodulin (Cal) gene of D. helianthi was selected to develop a rapid detection method involving recombinase polymerase amplification (RPA) combined with CRISPR/Cas12a-based detection at 37 °C. The developed detection system could complete the specific detection of D. helianthi in 45 min, including 25 min for RPA and 20 min for CRISPR/Cas12 reaction. The detection system could be coupled with both lateral flow test strips and fluorescence signal reading modes. The detection limit for lateral flow assay was 1 pg/μL genomic D. helianthi DNA (14 copies/µL); The detection limit for fluorescence signal was 0.1 pg/μL genomic DNA (1.4 copies/µL), approximately 100 times higher than that of the real-time PCR. Thus, the developed RPA/CRISPR-Cas12a system meets the need for portable detection of D. helianthi on-site at ports and in the field.

Differential Physiological Responses of Resistant and Susceptible Grape Cultivars to Eutypa dieback.

Eutypa lata is a fungal pathogen of grapevine that causes widespread economic damage and threatens vineyard longevity worldwide. This study was initiated to further understanding of how grapevines resist E. lata infections, using an integrated approach combining inoculation assays in the greenhouse with physiological and biochemical measurements. Resistant 'Zinfandel' and susceptible 'Syrah' grapevines were subjected to control and inoculation treatments and assessed for gas exchange, water status, photosynthetic biochemistry, hydraulic conductivity, wood chemistry, and fungal spread (lesion length). Infection reduced leaf photochemical function and gas exchange in Zinfandel and increased these variables in Syrah (p<0.05). Infection produced shorter lesions in Zinfandel (p<0.05), suggesting that downregulating gas exchange limited pathogen spread by reducing the carbon supply to the pathogen or fungal movement in the transpiration stream. Neither cultivar upregulated wood defense compounds in response to infection, but proanthocyanidin and catechin levels were constitutively higher in Zinfandel and stilbenoid and flavonoid contents were constitutively higher in Syrah (p<0.05). Altogether, this study is the first to show that, counterintuitively, downregulating physiological function in response to infection improves long-term resistance to E. lata. Screening responses in photochemical function or gas exchange could provide a high-throughput alternative to measuring lesion lengths in assessing resistance.

Rapid in vitro evolution of flucytosine resistance in Candida auris.

The pan-antifungal-resistant pathogen Candida auris has been causing high-mortality infection outbreaks in hospitals and healthcare settings. The prodrug 5-fluorocytosine (5FC) is one of four chemical entities, but its clinical use as an antifungal drug has been limited owing to pronounced resistance. However, antifungal combination therapy with 5FC appears as a promising strategy for treating C. auris infections. Here, we show that a C. auris clinical isolate can rapidly acquire genetic mutations to mount 5FC resistance after only one to two passages under drug selection. We exploit a new bioinformatics workflow to identify genetic polymorphisms from RNA-seq data. Strikingly, we identify several mutations in the FUR1 gene encoding the 5-fluorouracil convertase that normally generates the active drug. A single nonsense mutation truncates the enzyme at residue Q30*, leading to 5FC resistance due to inactive Fur1. Whole-genome sequencing analysis revealed that an indel mutation in FCY2 also contributes to 5FC resistance. Furthermore, at least one out of seven adapted strains acquired enhanced 5FC tolerance without mutations in the 5FC conversion pathway. Thus, we demonstrate that FUR1 mutations are critical drivers of 5FC resistance in C. auris.IMPORTANCECandida auris is a high-priority human fungal pathogen, causing infection outbreaks of high mortality in healthcare settings. Antifungal combination therapy with 5-fluorocytosine (5FC) is one of the emerging approaches in treatment. However, acquired 5FC resistance traits have been a matter of concern. 5FC is taken up by fungal cells via a cytosine permease and further metabolized by a cytosine deaminase to 5-fluorouracil (5FU). 5FU is then converted by the Fur1 uracil phosphoribosyltransferase into a toxic antimetabolite that disrupts fungal RNA and DNA syntheses. Mutations in these proteins are commonly associated with 5FC resistance in fungal species. Here, we show that C. auris can rapidly develop resistance under 5FC selective stress owing to mutational inactivation of Fur1 function. Moreover, other mechanisms that bypass mutations in the 5FC conversion pathway may also contribute to 5FC resistance traits. Finally, we have developed a tailored bioinformatics workflow that facilitates the identification of polymorphisms associated with 5FC resistance in clinical isolates.

A novel antifungal chitinase from Chaetomium globosum: column-free purification and characterization.

A new chitinase gene, cloned from the biocontrol Chaetomium globosum W7, was designated Cgchi18. Recombinant protein Cgchi18 with 535 amino acids was expressed in Escherichia coli, and purified by means of a column-free purification method relying on split intein, achieving a 12.39-fold purification and a 15.61% recovery yield. The maximum activity of this approximately 60-kDa protein was observed at 45°C and pH 5.0. Cgchi18 was activated by Mg2+ and Ba2+, but inhibited by Mn2+, Co2+, Cu2+, Zn2+, Ag+ and Hg2+. Cgchi18 showed high substrate specificity, only hydrolyzing β-1,4-glycoside bond in chitin and its derivatives, to liberate disaccharides or trisaccharides. For the degradation of colloidal chitin under optimal conditions, Vmax and Km of Cgchi18 were calculated as 8.05μmol/min/mg and 3.18mg/mL, respectively. Additionally, it exhibited antifungal activity and could have a degrading effect on the spread of hyphae of pathogenic fungi. In conclusion, the chitinase Cgchi18 identified from C. globosum has potential for industrial and agricultural applications.

The GPCR antagonist PPTN synergizes with caspofungin providing increased fungicidal activity against Aspergillus fumigatus

ABSTRACT Fungal pathogens pose a serious threat to human health, with Candida and Aspergillus spp. representing some of the most significant opportunistic invaders. Aspergillus fumigatus causes aspergillosis, one of the most prevalent fungal diseases of humans. There is a limited number of drugs available to combat these infections, and antifungal drug resistance is on the rise. In this manuscript, we show 4-[4-(4-Piperidinyl) phenyl]-7-[4-(-(trifluoromethyl) phenyl]-2-naphthalenecarboxylic acid (PPTN), a highly specific antagonist of the human P2Y14 receptor, is a promising antifungal adjuvant against diverse fungal pathogens. PPTN interacts with caspofungin (CAS), ibrexafungerp, voriconazole (VOR), and amphotericin against A. fumigatus CAS- and VOR-resistant clinical isolates, and also CAS against Candida spp and Cryptococcus neoformans . The combination of PPTN and CAS increases cell death in A. fumigatus . In the model yeast Saccharomyces cerevisiae, heterozygous deletion of genes involved in chromatin remodeling results in PPTN hypersensitivity, and in A. fumigatus , PPTN can have increased fungicidal activity when combined with the histone deacetylase inhibitor trichostatin A and the DNA methyltransferase inhibitor 5-azacytidine. Finally, PPTN has reduced toxicity to human immortalized cell lineages and partially clears A. fumigatus conidia infection in A549 pulmonary epithelial cells. Our results indicate that PPTN is a novel adjuvant antifungal drug against fungal diseases caused by A. fumigatus and Candida spp. IMPORTANCE Invasive fungal infections have a high mortality rate, causing more deaths annually than tuberculosis or malaria. Aspergillus fumigatus is the main etiological agent of aspergillosis, one of the most prevalent and deadly fungal diseases. There are few therapeutic options for treating this disease, and treatment commonly fails due to host complications or the emergence of antifungal resistance. Drug repurposing, where existing drugs are deployed for other clinical indications, has increasingly been used in the process of drug discovery. Here, we show that 4-[4-(4-Piperidinyl) phenyl]-7-[4-(-(trifluoromethyl) phenyl]-2-naphthalenecarboxylic acid (PPTN), a highly specific antagonist of the human P2Y14 receptor, when combined with caspofungin (CAS), ibrexafungerp, voriconazole (VOR), and amphotericin can increase the fungicidal activity against not only A. fumigatus CAS- and VOR-resistant clinical isolates but also CAS against Candida spp.

Threats from the Fungal Kingdom.

The fungal kingdom includes a large set of species with pathogenic potential for humans, plants, and wildlife. Whereas threats from the fungal kingdom to agriculture are appreciated, the potential of fungi to threaten humans, animals, ecosystems, and infrastructure is often unappreciated. Fungal disease and mold damage often follow natural disasters. The threats from the fungal kingdom are amplified by the relative paucity of countermeasures, which includes few antifungal drugs and fungicides and an increasing prevalence of resistance to both. Anthropomorphic climate change resulting in global warming is expected to increase the likelihood and potential number of threats from the fungal kingdom. Preparation against fungal threats requires continued investments in basic research to understand the unique aspects of fungal metabolism, development of vaccines, investment in new drugs and fungicides, and a careful mapping of the natural world to identify the existing taxonomic diversity and their potential for harm.

IL-1 protects from fatal systemic candidiasis in mice by inhibiting oxidative phosphorylation and hypoxia

Invasive C. albicans infections result in high mortality rates. While IL-1 is important to combat C. albicans infections, the underlying mechanisms remain unclear. Using global and conditional Il1r1 knockouts in mice, here we show that IL-1R signaling in non-hematopoietic cells in the kidney and brain is crucial for a protective response. In the kidney, endothelial IL-1R contributes to fungal clearance independent of neutrophil recruitment, while IL-1R in hematopoietic cells is dispensable. IL-1R signaling indirectly recruits neutrophils and monocytes in the brain by regulating chemokines and adhesion molecules. Single-nucleus-RNA-sequencing data implicates excessive metabolic activity and oxidative phosphorylation across all cell types in the kidney of Il1r1-deficient mice within a few hours upon infection, with associated, localized hypoxia at infection foci. Lastly, we find that hypoxia promotes fungal growth and pathogenicity. In summary, our results show that IL-1R-signaling in non-hematopoietic cells is required to prevent fatal candidiasis by inhibiting a metabolic shift, including excessive oxidative phosphorylation and hypoxia.

Antimicrobial Plant Peptides: Structure, Classification, Mechanism And Therapeutic Potential.

Humans, animals, and plants possess small polypeptides known as antimicrobial peptides (AMPs), which are often positively charged. They are tiny, mostly basic peptides with a molecular weight of 2 to 9 kDa. They are a crucial part of plants' innate defense system, acting as effector molecules that provide a resistance barrier against pests and diseases. Plants have been found to contain antimicrobial peptides belonging to numerous families, including plant defensins, thionins, cyclotides, and others. An increase in pathogen resistance is achieved through the transgenic overexpression of the relevant genes, while pathogen mutants that are susceptible to peptides exhibit decreased pathogenicity. For many organisms, AMPs exhibit a wide range of antimicrobial activity against various pathogens and serve as a crucial line of defense. This review raises awareness about plant antimicrobial peptides (AMPs) as potential therapeutic agents in the pharmaceutical and medical fields, including treating fungal and bacterial diseases. It also provides a broad synopsis of the main AMP families found in plants, their mechanisms of action, and the factors that influence their antimicrobial activities.

Aspergillus fumigatus secondary metabolite pyripyropene is important for the dual biofilm formation with Pseudomonas aeruginosa.

The human pathogenic fungus Aspergillus fumigatus establishes dual biofilm interactions in the lungs with the pathogenic bacterium Pseudomonas aeruginosa. Screening of 21 A. fumigatus null mutants revealed seven mutants (two G protein-coupled receptors, three mitogen-activated protein kinase receptors, a Gα protein, and one histidine kinase receptor) with reduced biofilm formation, specifically in the presence of P. aeruginosa. Transcriptional profiling and metabolomics analysis of secondary metabolites produced by one of these mutants, ΔgpaB (gpaB encodes a Gα protein), showed GpaB controls the production of several important metabolites for the dual biofilm interaction, including pyripyropene A, a potent inhibitor of mammalian acyl-CoA cholesterol acyltransferase. Deletion of pyr2, encoding a non-reducing polyketide synthase essential for pyripyropene biosynthesis, showed reduced A. fumigatus Δpyr2-P. aeruginosa biofilm growth, altered macrophage responses, and attenuated mouse virulence in a chemotherapeutic murine model. We identified pyripyropene as a novel player in the ecology and pathogenic interactions of this important human fungal pathogen.IMPORTANCEAspergillus fumigatus and Pseudomonas aeruginosa are two important human pathogens. Both organisms establish biofilm interactions in patients affected with chronic lung pulmonary infections, such as cystic fibrosis (CF) and chronic obstructive pulmonary disease. Colonization with A. fumigatus is associated with an increased risk of P. aeruginosa colonization in CF patients, and disease prognosis is poor when both pathogens are present. Here, we identified A. fumigatus genetic determinants important for the establishment of in vitro dual A. fumigatus-P. aeruginosa biofilm interactions. Among them, an A. fumigatus Gα protein GpaB is important for this interaction controlling the production of the secondary metabolite pyripyropene. We demonstrate that the lack of pyripyropene production decreases the dual biofilm interaction between the two species as well as the virulence of A. fumigatus in a chemotherapeutic murine model of aspergillosis. These results reveal a complete novel role for this secondary metabolite in the ecology and pathogenic interactions of this important human fungal pathogen.

Adiponectin pathway activation dampens inflammation and enhances alveolar macrophage fungal killing via LC3-associated phagocytosis.

Although innate immunity is critical for antifungal host defense against the human opportunistic fungal pathogen Aspergillus fumigatus, potentially damaging inflammation must be controlled. Adiponectin (APN) is an adipokine produced mainly in adipose tissue that exerts anti-inflammatory effects in adipose-distal tissues such as the lung. We observed increased mortality and increased fungal burden and inflammation in neutropenic mice with invasive aspergillosis (IA) that lack APN or the APN receptors AdipoR1 or AdipoR2. Alveolar macrophages (AMs), early immune sentinels that detect and respond to lung infection, express both receptors, and APN-deficient AMs exhibited an inflammatory phenotype that was associated with decreased fungal killing. Pharmacological stimulation of AMs with AdipoR agonist AdipoRon rescued deficient killing in APN-/- AMs and was dependent on the presence of either receptor. Finally, APN-enhanced fungal killing was associated with increased activation of the non-canonical LC3 pathway of autophagy. Thus, our study identifies a novel role for APN in LC3-mediated killing of A.fumigatus.

Temporal and Spatial Dynamics of Anthracnose (Colletotrichum sublineolum) Disease on Selected Sorghum Genotypes at Assosa Zone, Western Ethiopia

Background Over 500 million people worldwide rely on sorghum as a main food crop. About 10% of the daily caloric intake of households in Ethiopia’s northwest and eastern regions, including Benishangul Gumuz, comes from sorghum. A hemi-biotrophic fungal pathogen called Colletotrichum sublineolum caused anthracnose disease is among the biotic constraints of sorghum production. Methods Ten selected sorghum genotypes were assessed for sorghum anthracnose severity and its temporal and spatial dynamics on field plots in the districts of Assosa and Bambasi. The performance of the chosen sorghum genotypes was assessed using the following metrics: AUDPC, disease progress rate, yield-related trait, sorghum grain yield, and mean severity index. Anthracnose severity was evaluated using a 1–5 disease rating scale and assessments conducted at seven consecutive time points. Results The result found that the mean anthracnose severity index ranging from 60-77 PSI and 53-82 PSI, respectively. AUDPC varied from 351 to 470 % days and 316 to 499 % days at Assosa and Bambasi districts, respectively. Bambasi district achieved a larger grain yield than the Assosa district. Assosa-1 demonstrated a significant level of disease pressure, yet the current investigation found that this genotype is the highest performing genotype in both locations. Conclusions There is a considerable positive link between the severity of anthracnose and the weekly total rainfall and relative humidity. At both trial sites, Mersa-1 continuously produced higher grain yields and reduced disease levels. Breeders might utilize the Baco Striga sorghum genotype as a check line in a breeding effort to resist anthracnose disease because it shown a high vulnerability to the disease at both locations.

Roles of P-body factors in Candida albicans filamentation and stress response.

Hyphal growth is strongly associated with virulence in the human fungal pathogen Candida albicans. While hyphal transcriptional networks have been the subject of intense study, relatively little is known about post-transcriptional regulation. Previous work reported that P-Body (PB) factors Dhh1 and Edc3 were required for C. albicans virulence and filamentation, suggesting an essential role for post-transcriptional regulation of these processes. However, the molecular roles of these factors have not been determined. To further study the function of PB factors in filamentation, we generated homozygous deletions of DHH1 and EDC3 in diverse prototrophic clinical strains using transient CRISPR-Cas9. Homozygous DHH1 deletion strongly impaired growth, altered filamentation, and exhibited unusual colony morphology in response to heat stress in five strain backgrounds. Using RNA-seq, we found DHH1 deletion disrupts the regulation of thousands of genes under both yeast and hyphal growth conditions in SC5314 and P57055. This included upregulation of many stress response genes in the absence of external stress, similar to deletion of the S. cerevisiae DHH1 homolog. In contrast, we found EDC3 was not required for heat tolerance or filamentation in diverse strains. These results support a model in which DHH1, but not EDC3, represses hyphal stress response transcripts in yeast and remodels the transcriptome during filamentation. Our work supports distinct requirements for specific mRNA decay factors, bolstering evidence for post-transcriptional regulation of filamentation in C. albicans.

Hordeum jubatum: An alternative host for fungal pathogens attacking cultivated barley.

Wild grasses can serve as hosts for plant pathogens that attack small grain cereal crops, thereby perpetuating the disease cycle and potentially initiating epidemics. Foxtail barley (Hordeum jubatum) is a perennial grass species that is common across North America and can often be found growing near cultivated barley fields. Despite the close proximity of the two plant species in agro-ecosystems, few studies have been advanced to characterize the compatibility of H. jubatum to barley pathogens and its possible role in disease epidemiology. The objective of this study was to assess whether H. jubatum can act as a host to seven fungal pathogens causing diseases of barley. A collection of H. jubatum accessions (N=100) collected from sites in Minnesota, Wisconsin, and North Dakota in the U.S. and Manitoba in Canada were inoculated at the seedling or adult plant stage in the greenhouse with isolates of Dreschlera teres f. teres (causal pathogen of net form net blotch), Bipolaris sorokiniana (spot blotch), Puccinia graminis f. sp. tritici (stem rust), Blumeria graminis f. sp. hordei (powdery mildew), Puccinia striiformis f. sp. hordei (stripe rust), Puccinia hordei (leaf rust) and P. coronati-hordei (crown rust). None of the accessions showed any visual signs of infection when challenged with B. graminis f. sp. hordei and P. hordei. In contrast, from 97% to 100% of evaluated accessions were infected by D. teres f. teres, B. sorokiniana, P. graminis f. sp. tritici, P. striiformis f. sp. hordei, and P. coronati-hordei. The relative degree of compatibility of H. jubatum to these latter five pathogens ranged from low (similar to resistant barley) to high (similar to susceptible barley). These results demonstrate that H. jubatum can be infected by isolates of important barley pathogens, but typically not with the same degree of compatibility as susceptible barleys. Nevertheless, when infected plants of H. jubatum are growing near barley fields, they could serve as reservoirs of inoculum to initiate some diseases.

Genomic Characterisation of Bidens mottle virus in South Africa and an Assessment of the Impact on Helianthus annuus (Sunflower) in an Open Field Setting

ABSTRACTSunflower (Helianthus annuus) is an oilseed crop of global economic importance, and South Africa ranks among the 20 top producers worldwide. Sunflower production can be severely limited by fungal, viral and bacterial diseases. In South Africa, knowledge of viral diseases in sunflowers is particularly limited. During a disease survey of a field trial for a separate study, we observed symptoms not common in sunflowers in South Africa on several plants across the trial. This study aimed to identify the causal agent of these symptoms that were observed on sunflowers in two consecutive seasons at two experimental sites in South Africa (Pretoria and Potchefstroom). Illumina sequencing of total RNA from symptomatic leaves and reverse transcription‐PCR confirmation showed the presence of bidens mottle virus (BiMoV) in infected plants. BiMoV is a widespread potyvirus that is vectored by aphids, with weeds acting as viral reservoirs. The effects of the viral infection on the floral, morphological and yield traits in sunflowers were investigated. Pollen viability was reduced by 17.0%, plant height by 16.7%, leaf number by 12.3% and overall yield by 80.6%. This study suggests the potential for a significant impact from BiMoV infection on sunflower development and yield in South Africa. This is only the second report of natural infection of BiMoV in sunflowers and the first report of BiMoV in sunflowers in South Africa. We present preliminary evidence for yield losses; management strategies and disease progression need to be further investigated.

Identification and characterization of Fusarium acuminatum causing root rot on sesame in Noutheast of China.

Sesame is an important oil-producing crop, possessing approximately 50% oil and 20% protein content, along with a variety of antioxidant substances, endowing it with high edible and medicinal value. However, fungal diseases, especially Fusarium wilt with a high incidence, pose a significant threat and severely limit the development of the sesame industry. In this study, we identified symptoms of sesame fusarium wilt as with the midrib as the boundary, half of the leaf turns yellow while the other half remains normal, plantwilted and rotting roots, and eventually plant wilting and death. To identify the pathogen responsible, we employed a multi-faceted approach. Morphologically, we examined the color of the colonies and the specific morphology of the conidia. Moreover, we constructed a phylogenetic tree based on the DNA sequences of ITS and TEF1-α. Through these combined efforts, the pathogen was identified as F. acutuminatum. Subsequently, pathogenicity tests were carried out, and the results unequivocally demonstrated that F. acutuminatum was capable of inducing the characteristic symptoms of Fusarium wilt in sesame seedlings, including root rot and leaf yellowing. This study identified key aspects of sesame Fusarium wilt. The determined symptoms and pathogen, along with proven pathogenicity, offer a theoretical basis for devising strategies to prevent and treat this disease, potentially enhancing sesame industry sustainability.

Performance evaluation of cationic cellulose for anionic dyes adsorption from real wastewater and docking studies

In this study, cationic cellulose fiber adsorbent was prepared through a two-step reaction from commercial cellulose, using an oxidizing agent (sodium periodate) and Girard’s reagent as a cationizing agent. The performance of cationic cellulose for adsorption and separation dye was examined by anionic organic dyes. The prepared adsorbent was able to remove the dyes with the maximum adsorption capacity for Eriochrome Cyanine R, methyl orange, and Zincon being 65.33, 63.33, and 65.32 mg/g, respectively. To explore the adsorption mechanism of the sorbent, the influence of pH, initial dye concentration, contact time, temperature, and adsorbent dose on the activity of adsorption towards anionic dyes were studied, as was the equilibrium dose of cationic cellulose (0.075 g) for removal of 100 mg/L from the studied dyes. The equilibrium data adsorption of cationic cellulose was discovered to be suitable well to the Langmuir isotherm model with correlation coefficient (R2 > 0.982) and pseudo-second-order model. The process of dyes adsorption on cellulose functionalized was spontaneous exothermic (∆G and ∆S < 0), monolayer chemisorption. Utilizing the molecular operating environment software, molecular docking simulations were performed for the cellulose functionalized compound. The results from the docking simulation demonstrated that the modified cellulose compound exhibited increased potency and displayed a higher binding affinity towards the Avr2 effector protein obtained from the fungal plant pathogen Fusarium oxysporum (code 5OD4). The modified cellulose was successfully utilized for the anionic dyes removal from real wastewater samples and synthetic effluents, with a recovery % of more than 87%. The distinctive complementary features of regenerated cellulose will facilitate its removal of a variety of organic dyes from wastewater of industries.