Search Results (25)

Peanut Root Rot (PRR) is a devastating disease that significantly limits peanut production worldwide. Although PRR has been frequently reported in Henan Province of China, the predominant Fusarium species and their sensitivity to different fungicides remain unclear. Between 2021 and 2023, we surveyed 81 peanut fields across 17 cities in Henan Province, China, to assess PRR prevalence and Fusarium species distribution. A total of 1131 Fusarium isolates were identified based on the morphological characters and phylogenetic analyses and classified into 11 recognized Fusarium species: F. solani (56.06%), F. oxysporum (20.87%), F. neocosmosporiellum (13.62%), F. proliferatum (4.69%), F. acuminatum (1.33%), F. commune (1.15%), F. graminearum (1.06%), F. pseudograminearum (0.35%), F. ipomoeae (0.35%), F. lacertarum (0.26%), and F. armeniacum (0.26%). Pathogenicity assessments showed that all 11 Fusarium species were capable of causing PRR, with F. solani exhibiting the highest isolation frequency and widespread distribution in all areas. Furthermore, the four Fusarium species (F. solani, F. oxysporum, F. neocosmosporiellum, and F. proliferatum) were highly sensitive to the six fungicides, including prochloraz (EC₅₀ values of 0.02 ± 0.00~0.06 ± 0.01 mg/L), pydiflumetofen (EC₅₀ values of 0.31 ± 0.07~0.67 ± 0.06 mg/L), tetramycin (EC₅₀ values of 0.11 ± 0.02~0.58 ± 0.08 mg/L), tebuconazole (EC₅₀ values of 0.26 ± 0.07~0.65 ± 0.10 mg/L), prothioconazole (EC₅₀ values of 1.14 ± 0.16~3.15 ± 0.81 mg/L), and difenoconazole (EC₅₀ values of 0.62 ± 0.12~3.58 ± 0.76 mg/L). This comprehensive study is the first systematic documentation on the prevalence, virulence, and fungicide sensitivity of PRR pathogens in Henan Province. The findings of the current study will provide a theoretical basis for the effective management of peanut root rot in Henan, China. Full article

Fusarium acuminatum is a major pathogenic fungus causing root rot in alfalfa (Medicago sativa). DNA polymerase theta is known to play a crucial role in repairing DNA double-strand breaks. However, its biological function in F. acuminatum remains unknown. In this study, the POLQ gene was deleted by homologous recombination using Agrobacterium tumefaciens-mediated transformation. Compared to the wild type (with the POLQ gene), the mutants (without the POLQ gene) showed significant phenotypic changes: they produced brown-yellow pigments instead of pink, slowed mycelial growth, and exhibited changes in macroconidia size and shape. The virulence of the mutants was greatly reduced, inducing only mild symptoms in alfalfa. In addition, FITC-WGA staining showed impaired spore germination and hyphal growth. These results suggest that POLQ is a key gene regulating growth and development of F. acuminatum, indicating that DNA repair may play an essential role in the pathogenicity of the pathogen in alfalfa. The POLQ gene could thus be a promising target for limiting F. acuminatum infections in alfalfa. Full article

Benthic diatoms are being used as indicators to assess the biological quality of surface waters in Kosovo. The Klina River is the left tributary of the White Drin River Basin, with a length of 69 km. The study assessed the level of surface water quality in the Klina River using 12 diatomic indices calculated with the Omnidia program. For this purpose, three stations monitored the river Klina in the autumn of 2021 to conform to international standards. A total of 88 diatom taxa were identified, with the dominant species being Rhoicosphenia abbreviata (C. Agardh) Lange-Bertalot, Gyrosigma acuminatum (Kützing) Rabenhorst, Cocconeis placenula Ehrenberg, Gomphonema minutum (Ag.) Agardh f. minutum, Gomphonema clavatum Ehr, Meridion circulare (Greville) C.A. Agardh, Cocconeis pediculus Ehrenberg, Diatoma vulgaris Bory, and Nitzschia dissipata (Kützing) Grunow ssp. dissipata etc. This study assessed the surface water quality in the Klina River using diatom indices, indicating that the river is in good to moderate ecological condition. Environmental variables such as hydrogen ion concentration (pH) and dissolved oxygen (DO) had significant positive correlations (<0.01) with the biological diatom index (IBD), Descy’s pollution metric (Descy), Sladeček’s pollution metric (SLA), the European index (CEE), and Watanabe’s Index (WAT), while the total suspended solids (TSS) also showed a strong negative significant correlation (<0.01) with the generic diatom index (IDG), Indice Diatomique Artois Picardie (IDAP), the eutrophication pollution index (EPI-D), the trophic diatom index (TDI), the Pampean diatom index (IDP), and Steinberg and Schiefele’s index (SHE). Total phosphorus (TP), biochemical oxygen demand (BOD), and chemical oxygen demand (COD) presented a significant negative correlation (<0.05) with the IBD, Descy, SLA, CEE, and WAT indices. Our findings provide insights for organizations dealing with the state of the environment and water protection in Kosovo, and these results can be used as a starting point for assessing the ecological quality of water and monitoring environmental pollution in the Kosovo region. Full article

High-throughput sequencing (HTS) has revolutionized phytopathology by overcoming many limitations of traditional diagnostic methods, as it permits precise pathogen monitoring, identification, and control, with ribosomal DNA (rDNA) regions serving as reliable markers for fungal classification. In this study, next-generation sequencing (NGS) was used, targeting the ITS1 and ITS2 regions to explore fungal diversity and pathogen presence in winter wheat grain samples and identifying 183 OTU sequences across 115 taxa. The ITS1 analysis yielded 249,743 reads, with Fusarium sp. (61%) as the dominant pathogenic taxon, followed by Sporobolomyces sp. (14%), Cladosporium sp. (3%), and other yeast-like or saprotrophic fungi, such as Cryptoccocus spp., F. wieringae, and B. alba. Sequencing of ITS1 also permitted the detection of F. acuminatum and the quarantine-regulated pathogens T. caries and T. triticoides. The ITS2 analysis produced 179,675 reads, with F. culmorum (47%) as the most abundant taxon, confirming significant grain contamination with this pathogen. Other frequently detected taxa included yeast-like fungi such as C. tephrensis (21%) and V. victoriae (13%), along with saprotrophic species like S. roseus and Davidella sp. ITS2 provided better resolution for the identification of Fusarium species by the detection of more pathogenic taxa associated with cereal diseases, including F. culmorum, as well as F. cerealis, F. poae, and F. tricinctum. The analysis revealed a diverse fungal community, including other pathogens such as A. porri, B. cinerea, and C. herbarum, as well as various non-pathogenic and saprotrophic fungal taxa. These findings underscore the complementary utility of ITS1 and ITS2 in profiling fungal diversity and detecting critical pathogens using HTS, highlighting the potential of these DNA regions for monitoring and managing cereal crop health. Full article

The Fusarium species is an important plant pathogen that can cause plant diseases in grassland, leading to the degradation of grassland quality. However, the morphology of Fusarium is greatly affected by environmental factors, which makes it difficult to identify its species. In addition, the pathogenic ability of different Fusarium species in plants has not been fully studied. In this study, Fusarium isolates were obtained from grassland herbaceous plants via tissue separation. Through morphological means and based on ITS, RPB2, and TEF-1 gene sequences, we compared and constructed polygenic phylogenetic trees to classify and identify the Fusarium species. In addition, the pathogenicity of different Fusarium species was also analyzed. The results showed that a total of 24 Fusarium strains were successfully isolated from grassland, from which ten species were identified: F. flagelliforme, F. longifundum, F. clavum, F. scirpi, F. ipomoeae, F. oxysporum, etc. and were included in four complexes: Fusarium incarnatum-equiseti species complex (FIESC), Fusarium oxysporum species complex (FOSC), Fusarium tricinctum species complex (FTSC), and Fusarium sambucinum species complex (FSAMSC). Pathogenicity tests demonstrated that except for F. ipomoeae QJ5211, F. sambucinum QJ203, and F. acuminatum QJ1662, other Fusarium species had different degrees of pathogenic ability. This is the first study that discusses the effect of Fusarium on grassland disease control in this area. This study further provides clear pathogen information for the prevention and control of grassland diseases. Full article

Fusarium acuminatum is recognized as the causative agent of root rot in many forestry and agricultural plants. In recent years, root rot and foliage blight caused by F. acuminatum have become widespread and severe in China, particularly affecting Dianthus chinensis. The infection mechanism of F. acuminatum remains a pressing area for research. A crucial approach to elucidating its pathogenic mechanisms involves the genetic modification of candidate genes, which necessitates effective transformation systems. Currently, protoplast-mediated transformation (PMT) serves as a valuable tool for studying plant-pathogen interactions and offers several advantages over conventional transformation methods. In this study, we employed the PMT technique to establish a transformation system for the F. acuminatum strain FDCY-5 due to its benefits such as ease of operation, low cost, high conversion efficiency, and broad applicability. We successfully developed a transformation system capable of producing abundant high-quality protoplasts from F. acuminatum and generating green fluorescent protein (GFP) transformants. To verify whether GFP was constitutively expressed, we utilized fluorescence microscopy alongside PCR technology. The results demonstrated that GFP was effectively transformed into the protoplasts of F. acuminatum and expressed successfully. The established protoplast transformation system for F. acuminatum provides a foundational platform for analyzing functional genes within infected host plants as well as understanding the molecular mechanisms underlying host plant infections by F. acuminatum. Full article

Fusarium spp. can cause root rot in alfalfa, leading to the death of the whole plant, which seriously affects the yield and quality of alfalfa. This study used a Fusarium acuminatum strain labeled with green fluorescent protein (GFP) to observe the infection process of F. acuminatum on alfalfa by confocal fluorescence microscopy. The aim of this study was to reveal the infection mechanism of alfalfa Fusarium root rot at the cellular histological level. The results showed that conidia of F. acuminatum attached to the surface of the root and germinated at one day post-inoculation, the mycelium then entered the vascular bundle tissue of the alfalfa root at 5 days post-inoculation, reached the base of the plant stem at 14 days post-inoculation, and colonized the stem of the first and second compound leaf at 28 and 49 days post-inoculation, respectively. Moreover, the experiment, which sprayed a spore suspension, showed that the conidia of F. acuminatum could spread through the air to infect the pericarp and seed coat tissue of the pod. For the first time, we report the infection process of alfalfa Fusarium root rot caused by F. acuminatum and clarify that F. acuminatum can initially infect the root tissue of alfalfa, colonize the bottom stem of the plant through systematic infection, and eventually cause the plant to wilt and die. The results reveal the infection mechanism of F. acuminatum at the cell level via histology and provide theoretical support for the development of control strategies and key control technologies for alfalfa root rot. Full article

Root rot caused by Fusarium spp. is a significant issue in the chickpea-growing regions of Montana. The specific Fusarium species responsible for the disease and their prevalence remain uncertain. A survey was conducted in 2020 and 2021 to identify Montana’s Fusarium species associated with chickpea. Four hundred and twenty-six Fusarium isolates were recovered from symptomatic chickpea roots across ten counties in the state. Isolates were identified by comparing translation elongation factor 1-α (TEF1-α) sequences in the FUSARIUM-ID database. Among the recovered isolates, Fusarium oxysporum was the most prevalent species (33%), followed by F. acuminatum (21%), F. avenaceum (15%), F. redolens (14%), F. culmorum (6%), F. sporotrichioides (6%), Neocosmospora solani (6%), F. equiseti (2%), F. torulosum (0.9%), F. gamsii (0.8%), F. proliferatum (0.2%), F. pseudograminearum (0.2%), and F. brachygibbosum (0.1%). The aggressiveness of a subset of 51 isolates representing various Fusarium spp. was tested on chickpea cv. ‘CDC Frontier’. A non-parametric variance analysis conducted on disease severity ranks indicated that F. avenaceum isolates were highly aggressive. This study reports for the first time that F. gamsii, F. proliferatum and F. brachygibbosum are causal agents of root rot in chickpea in the United States. This knowledge is invaluable for making informed decisions regarding crop rotation, disease management, and developing resistant chickpea varieties against economically significant Fusarium pathogens. Full article

Fusarium basal rot of onions causes large losses during storage of commercial production of onion bulbs, which in turn adversely affects the food market situation in the off-season period. There are no data on the composition of Fusarium spp., which causes onion basal rot in the Russian Federation. Therefore, our research was aimed at Fusarium spp. causing onion basal rot in the Moscow Region of the Russian Federation and studying the pathogenicity of these species for the host plant. We studied 20 isolates of Fusarium spp. collected from affected mature bulbs and seed bulbs. Species identification of the isolates was carried out using analysis of the nucleotide sequences of the three genetic loci ITS, tef1 and rpb2, as well as was based on the macro- and micromorphological characteristics of these isolates. As a result, the species F. annulatum (F. fujikuroi species complex), F. oxysporum (F. oxysporum species complex), F. acuminatum (F. tricinctum species complex) and F. solani (F. solani species complex) were identified to involve in the pathogenesis of Fusarium basal rot. We have shown for the first time that the species F. annulatum and F. acuminatum are highly aggressive and capable of causing onion basal rot. The predominant species were F. annulatum and F. oxysporum. The proportion of these species in the total number of analyzed isolates was 60% and 25%, respectively. The largest proportion (33%) of highly aggressive on mature bulbs isolates was found in the species F. annulatum. The data obtained provide practical insights for developing strategies to manage Fusarium fungi responsible for onion basal rot Moscow Region of the Russian Federation. In addition, data about species composition and aggressive isolates may be used in onion breeding for resistance to Fusarium basal rot. Full article

Fusarium spp. are commonly associated with the root rot complex of soybean (Glycine max). Previous surveys identified six common Fusarium species from Manitoba, including F. oxysporum, F. redolens, F. graminearum, F. solani, F. avenaceum, and F. acuminatum. This study aimed to determine their pathogenicity, assess host resistance, and evaluate the genetic diversity of Fusarium spp. isolated from Canada. The pathogenicity of these species was tested on two soybean cultivars, ‘Akras’ (moderately resistant) and ‘B150Y1′ (susceptible), under greenhouse conditions. The aggressiveness of the fungal isolates varied, with root rot severities ranging from 1.5 to 3.3 on a 0–4 scale. Subsequently, the six species were used to screen a panel of 20 Canadian soybean cultivars for resistance in a greenhouse. Cluster and principal component analyses were conducted based on the same traits used in the pathogenicity study. Two cultivars, ‘P15T46R2′ and ‘B150Y1′, were consistently found to be tolerant to F. oxysporum, F. redolens, F. graminearum, and F. solani. To investigate the incidence and prevalence of Fusarium spp. in Canada, fungi were isolated from 106 soybean fields surveyed across Manitoba, Saskatchewan, Ontario, and Quebec. Eighty-three Fusarium isolates were evaluated based on morphology and with multiple PCR primers, and phylogenetic analyses indicated their diversity across the major soybean production regions of Canada. Overall, this study contributes valuable insights into host resistance and the pathogenicity and genetic diversity of Fusarium spp. in Canadian soybean fields. Full article

Fusarium root rot, caused by Fusarium spp. in alfalfa (Medicago sativa L.), adversely impacts alfalfa by diminishing plant quality and yield, resulting in substantial losses within the industry. The most effective strategy for controlling alfalfa Fusarium root rot is planting disease-resistant varieties. Therefore, gaining a comprehensive understanding of the mechanisms underlying alfalfa’s resistance to Fusarium root rot is imperative. In this study, we observed the infection process on alfalfa seedling roots infected by Fusarium acuminatum strain HM29-05, which is labeled with green fluorescent protein (GFP). Two alfalfa varieties, namely, the resistant ‘Kangsai’ and the susceptible ‘Zhongmu No. 1’, were examined to assess various physiological and biochemical activities at 0, 2, and 3 days post inoculation (dpi). Transcriptome sequencing of the inoculated resistant and susceptible alfalfa varieties were conducted, and the potential functions and signaling pathways of differentially expressed genes (DEGs) were analyzed through gene ontology (GO) classification and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. Meanwhile, a DEG co-expression network was constructed though the weighted gene correlation network analysis (WGCNA) algorithm. Our results revealed significant alterations in soluble sugar, soluble protein, and malondialdehyde (MDA) contents in both the ‘Kangsai’ and ‘Zhongmu No. 1’ varieties following the inoculation of F. acuminatum. WGCNA analysis showed the involvement of various enzyme and transcription factor families related to plant growth and disease resistance, including cytochrome P450, MYB, ERF, NAC, and bZIP. These findings not only provided valuable data for further verification of gene functions but also served as a reference for the deeper explorations between plants and pathogens. Full article

T-2 mycotoxin is the most potent representative of the trichothecene group A and is produced by various Fusarium species, including F. sporotrichioides, F. poae, and F. acuminatum. T-2 toxin has been reported to have toxic effects on various tissues and organs, and humans and animals alike suffer a variety of pathological conditions after consumption of mycotoxin-contaminated food. The T-2 toxin’s unique feature is dermal toxicity, characterized by skin inflammation. In this in vitro study, we investigated the molecular mechanism of T-2 toxin-induced genotoxicity in the human skin fibroblast—Hs68 cell line. For the purpose of investigation, the cells were treated with T-2 toxin in 0.1, 1, and 10 μM concentrations and incubated for 24 h and 48 h. Nuclear DNA (nDNA) is found within the nucleus of eukaryotic cells and has a double-helix structure. nDNA encodes the primary structure of proteins, consisting of the basic amino acid sequence. The alkaline comet assay results showed that T-2 toxin induces DNA alkali-labile sites. The DNA strand breaks in cells, and the DNA damage level is correlated with the increasing concentration and time of exposure to T-2 toxin. The evaluation of nDNA damage revealed that exposure to toxin resulted in an increasing lesion frequency in Hs68 cells with HPRT1 and TP53 genes. Further analyses were focused on mRNA expression changes in two groups of genes involved in the inflammatory and repair processes. The level of mRNA increased for all examined inflammatory genes (TNF, INFG, IL1A, and IL1B). In the second group of genes related to the repair process, changes in expression induced by toxin in genes—LIG3 and APEX were observed. The level of mRNA for LIG3 decreased, while that for APEX increased. In the case of LIG1, FEN, and XRCC1, no changes in mRNA level between the control and T-2 toxin probes were observed. In conclusion, the results of this study indicate that T-2 toxin shows genotoxic effects on Hs68 cells, and the molecular mechanism of this toxic effect is related to nDNA damage. Full article

In October 2020, samples of walnut branch blight were collected from Longnan. Pathogens were isolated and identified based on morphological and molecular features, and their characteristics were analyzed by pathogenicity. Pathogenicity testing revealed that seven strains (LN-1, LN-3, LN-6, LN-19, LN-27, QY3-1, and QY9-1) induced symptoms of walnut branch blight that were consistent with those observed in the field after inoculation. Furthermore, some Fusarium-type conidia and spherical chlamydospores were visible indicating that they were Fusarium spp. A molecular characterization including sequence and phylogenetic analysis of the ITS, TEF-1α, βTUB, Fu, and LSU gene regions revealed that LN-1 and LN-19 belonged to F. avenaceum, LN-3 and LN-6 to F. acuminatum, LN-27 to F. sporotrichioides, and QY3-1 and QY9-1 to F. tricinctum. This is the first time that F. acuminatum-, F. sporotrichioides-, and F. tricinctum-caused walnut branch blight has been reported in China. Full article

This study examined the biological activity and genome of Bacillus cereus CDHWZ7 isolated from the root of Lycium ruthenicum in the Dachaidan saline area, Haixi Prefecture, Qinghai Province, China. The results revealed that B. cereus CDHWZ7 exhibited strong inhibition activity against the pathogenic fungi Fusarium graminearum, F. acuminatum, and F. oxysporum. CDHWZ7 also demonstrated cellulose-degrading activity, nitrogen-fixing activity, and the ability to secrete indole-3-acetic acid (IAA) at 55.00 mg∙L⁻¹. The strain CDHWZ7 can grow at a salt concentration of 3–11%, a pH range of 5–11, and a temperature of 4 °C–18 °C, and shows good salt tolerance, acid and alkaline tolerance, and low-temperature fitness. The genome of strain CDHWZ7 was sequenced using Illumina HiSeq + PacBio, revealing a circular structure of 5,648,783 bp in length, containing two intact plasmids with an average GC content of 35.2%, and a total number of 5672 encoded genes. It contained 106 tRNA genes, 42 rRNA genes, and 134 sRNA genes. A total of 137 genes were annotated as carbohydrases, with a total base length of 3,968,396,297 bp. The numbers of coding sequences assigned to the Kyoto Encyclopedia of Genes and Genomes, Clusters of Orthologous Groups of Proteins, and Gene Ontology Databases were 4038, 4133, and 2160, respectively. Further analysis of the genome identified genes encoding chitinase activity, cellulases, secondary metabolites, phytohormone production, volatile compounds, nitrogen and phosphate metabolism, and resistance responses to biotic stresses (glycine betaine transporter protein, catalase, superoxide dismutase, low-affinity potassium transporter protein, cold-shock protein, heat-shock protein), as well as genes related to proliferation, stress response, and resistance to pathogenic fungi. Therefore, this study determined that strain CDHWZ7 has several excellent biological traits, such as antagonism to pathogenic fungi, nitrogen-fixation ability, cellulose-degradation ability, and IAA-production ability. The genome sequence of strain CDHWZ7 and several biodefense functional genes were also analyzed, revealing the potential use of strain CDHWZ7 in the development of biological agents. Full article

French tamarisk, Tamarix gallica L. (family Tamaricaceae) is a deciduous tree that, like other halophytes, grows in a wide variety of saline habitats thanks to its powerful phenolics-based antioxidant system. Given that antioxidant properties are usually linked to the presence of compounds with antifungal properties, in the work presented herein the antimicrobial activity of T. gallica bark extract was investigated against four phytopathogenic species of genus Fusarium. According to the results of gas chromatography–mass spectroscopy, the phytochemical profile of the aqueous ammonia extract included 1-(2,4,6-trihydroxyphenyl)-2-pentanone; 3,5-dimethoxy-4-hydroxycinnam aldehyde; trans-squalene; 4-hydroxy-3,5-dimethoxy-benzaldehyde; dihydro-3-methylene-2,5-furandione; 1-(4-hydroxy-3,5-dimethoxyphenyl)-ethanone; and 4-hydroxy-3,5-dimethoxy-benzoic acid as main constituents. Concerning in vitro antifungal activity, EC₉₀ effective concentrations in the 335–928 μg·mL⁻¹ range were obtained against F. acuminatum, F. culmorum, F. equiseti, and F. graminearum, remarkably lower than those of two conventional fungicides (viz. mancozeb and fosetyl-Al). The antifungal activity of the extract was tested further in wheat and maize grain protection bioassays, confirming that the treatment effectively controlled F. graminearum at a concentration of 375 µg·mL⁻¹. Given this promising activity, T. gallica bark extracts may be susceptible to valorization as a natural and sustainable biorational for Fusarium spp. control. Full article