Aug 2026· Frontiers in Plant Science· 0 citations· 35 references
TL;DR
Findings underscore a significant role for VdOMO in siderophore-associated iron acquisition, fungal development, stress adaptation, and the early stages of host colonization in V. dahliae.
Abstract
Verticillium dahliae
is a soilborne fungal pathogen that causes Verticillium wilt in cotton and many other crops. While siderophore-associated iron acquisition is recognized as crucial, its precise connections to fungal development, stress adaptation, and host colonization remain incompletely elucidated. This study identifies the VdOMO protein as a putative SidA-family L-ornithine N5-monooxygenase through phylogenetic and pairwise sequence analyses. Analyses of independent deletion mutants and a complemented strain showed that
VdOMO
contributes to conidial morphology and production, microsclerotium formation, and melanization, growth on selected carbon sources, cell wall integrity, and adaptation to alkaline, salt, and oxidative stresses. Although final visible disease symptoms were comparable among inoculated groups,
ΔVdOMO
mutants exhibited reduced vascular browning, diminished fungal biomass accumulation at early infection stages, and impaired cellophane penetration. A representative
ΔVdOMO
mutant also displayed decreased biomass-normalized extracellular chrome azurol S (CAS)-reactive iron-chelating activity and intracellular iron accumulation, both of which were restored to wild-type levels upon complementation. Furthermore,
VdOMO
deletion was linked to iron-condition-dependent alterations in the expression of genes involved in iron regulation, siderophore biosynthesis, and siderophore transport. Collectively, these findings underscore a significant role for
VdOMO
in siderophore-associated iron acquisition, fungal development, stress adaptation, and the early stages of host colonization in
V. dahliae
.
Verticillium dahliae is a soil-borne vascular pathogen with a broad host range and the ability to survive in soil for extended periods through the formation of stress-resistant microsclerotia. It poses a major challenge to disease management and frequently causes severe Verticillium wilt in smoke tree (Cotinus coggygria) in China. Zn(II)2Cys6 transcription factors (TFs) represent a major class of fungal regulators and are involved in various biological processes, including primary and secondary metabolism, stress adaptation, and pathogenesis. In this study, we found that the deletion of VdRgt1, which belongs to Zn(II)2Cys6 TF, led to abnormal hyphal morphology, reduced vegetative growth, markedly decreased conidial production, and altered timing of microsclerotia development and melanin accumulation. Additionally, the ΔVdRgt1 mutant exhibited significantly reduced virulence and impaired colonization of C. coggygria. Transcriptome analysis indicated that VdRgt1 is involved in the regulation of carbohydrate and energy metabolism. Consistently, the ΔVdRgt1 mutant exhibited reduced ATP levels, and RT-qPCR supported a role for VdRgt1 in glucose-responsive gene regulation. Collectively, these results indicate that VdRgt1 is an important regulator in V. dahliae, coordinating hyphal development, the timing of microsclerotia development and melanin accumulation, carbon and energy metabolism, stress adaptation, and virulence.
It is demonstrated that AaAtg4 is important for spore germination, siderophore biosynthesis, iron acquisition, oxidative stress resistance, and toxin production, thereby establishing its critical role in A. alternata virulence.
Hsin-Yu Lu, C. H. Y. Choo, Je-Jia Wu et al.· Fungal Genetics and Biology· 0 citations
These findings provide the first insights into the multifaceted roles of intracellular β-N-acetylhexosaminidase Hex2 in B. bassiana, identifying a rational target for engineering insecticides with remained or even enhanced pesticidal efficacy.
Yu Li, Zhi-Hao Yang, Yu-tian Li et al.· Journal of Invertebrate Path...· 0 citations
Highlights This VdPRMT1 is a conserved arginine methyltransferase in Verticillium dahliae. VdPRMT1 contributes to fungal growth, stress adaptation, carbon utilization, and virulence. HIGS-mediated silencing of VdPRMT1 reduces Verticillium wilt severity in cotton. VdPRMT1 interacts with VdLuc7, indicating a potential link to RNA processing. Abstract Protein arginine methyltransferases (PRMTs) are key regulators of diverse cellular processes in eukaryotes, including transcriptional regulation, RNA processing, signal transduction and DNA repair. However, the biological functions of PRMTs in Verticillium dahliae remain largely unexplored. In this study, we identified a PRMT1 homolog in V. dahliae. Targeted deletion of VdPRMT1 resulted in severely impaired hyphal growth, sporulation, stress responses and pathogenicity. Subcellular localization analysis showed that VdPRMT1 is distributed in both the nucleus and cytoplasm of hyphae. Host-induced gene silencing (HIGS) of VdPRMT1 in cotton significantly reduced disease severity, supporting its important role in pathogenicity. Furthermore, VdLuc7, a U1 snRNP-associated protein containing multiple RG/RGG motifs, was identified as a putative interacting partner of VdPRMT1 through yeast two-hybrid (Y2H) screening, bimolecular fluorescence complementation (BiFC) and luciferase complementation imaging (LCI) assays. Together, our results demonstrate that VdPRMT1 is required for normal fungal development and full virulence in V. dahliae, and suggest that arginine methylation may contribute to pathogenicity through regulation of RNA processing-related pathways. These findings provide new insights into the molecular mechanisms underlying fungal virulence and identify VdPRMT1 as a potential target for disease control.
The results suggest that TrcrtB and phytoene are critical for development, stress tolerance and pathogenicity of T. roseum and highlight the roles of TrcrtB and phytoene in the pathogenic fungus T. roseum.
Colletotrichum fructicola, the primary causal agent of Glomerella leaf spot (GLS), is a destructive fungal pathogen of apple, whose underlying pathogenic mechanisms remain largely unknown. A previous transcriptomic analysis of infected leaves indicated induction of the transcription factor CfMBZ1. This study confirmed that CfMBZ1 is highly expressed in conidia and during early infection. To elucidate its function, we generated a ΔCfMBZ1 deletion mutant via homologous recombination. Phenotypic analysis revealed that ΔCfMBZ1 lost pathogenicity on apple leaves due to a blockage in appressorium-mediated host penetration, despite retaining the ability to form penetration pegs on cellophane. However, extension of invasive hyphae and necrotrophic growth in wounded apple fruit were unaffected. The mutant also exhibited defects in maintaining the integrity of the cell wall and cell membrane, as well as in tolerating oxidative and acid–base stress. Comparative transcriptome analysis suggested that CfMBZ1 regulates appressorium-mediated penetration by modulating genes involved in peroxisome biogenesis, lipid droplet metabolism, and other penetration-related pathways. Our findings reveal that CfMBZ1 plays a critical role in the pathogenesis of Glomerella leaf spot caused by C. fructicola.
Wenkui Liu, Wenxin Shi, Yecan Pan et al.· Phytopathology Research· 0 citations