The HAP complex in Fusarium verticillioides is a key regulator of growth, morphogenesis, secondary metabolism, and pathogenesis

Ridenour, John B.; Bluhm, Burton H.

doi:10.1016/j.fgb.2014.05.003

Cited by 20 publications

(21 citation statements)

References 65 publications

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“…In addition, activation of the gene encoding the cellobiohydrolase II cellulose degrading enzyme (cbh2) is mediated by the Hap3 orthologue (HapC) in the biomass-degrading fungus Trichoderma reesei 23 . Recently, a few orthologues of HAP complex components and the histone-like protein have been characterized in plant pathogenic fungi, including Fusarium species [24][25][26] . These proteins are involved in pathogenesis, fungal development, and various biological processes, yet interactions between CCAAT-binding factors have not been investigated in plant pathogenic fungi, including F. graminearum.…”

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confidence: 99%

Characterization of the CCAAT-binding transcription factor complex in the plant pathogenic fungus Fusarium graminearum

Kim

Nam

Park

et al. 2020

Sci Rep

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the ccAAt sequence is a ubiquitous cis-element of eukaryotic promoters, and genes containing CCAAT sequences have been shown to be activated by the CCAAT-binding transcription factor complex in several eukaryotic model organisms. In general, CCAAT-binding transcription factors form heterodimers or heterotrimeric complexes that bind to ccAAt sequences within the promoters of target genes and regulate various cellular processes. To date, except Hap complex, CCAAT-binding complex has been rarely reported in fungi. In this study, we characterized two CCAAT-binding transcription factors (Fct1 and Fct2) in the plant pathogenic fungus Fusarium graminearum. Previously, FCT1 and FCT2 were shown to be related to DnA damage response among eight ccAAt-binding transcription factors in F. graminearum. We demonstrate that the nuclear CCAAT-binding complex of F. graminearum has important functions in various fungal developmental processes, not just DNA damage response but virulence and mycotoxin production. Moreover, the results of biochemical and genetic analyses revealed that Fct1 and Fct2 may form a complex and play distinct roles among the eight CCAAT-binding transcription factors encoded by F. graminearum. To the best of our knowledge, the results of this study represent a substantial advancement in our understanding of the molecular mechanisms underlying the functions of CCAAT-binding factors in eukaryotes. Gene expression is primarily orchestrated by a set of transcription factors that bind to cis-elements in promoter regions 1. In addition to the TATA-box, the CCAAT sequence is a ubiquitous cis-element of eukaryotic promoters that is present in the promoters of approximately 30% of eukaryotic genes 2. Therefore, genes carrying a CCAAT-box are known to be primarily activated by conserved CCAAT-binding complexes in model eukaryotic organisms 3. The CCAAT-binding complex (CBC) typically consists of heterotrimeric core subunits and regulates primary/ secondary metabolism, development, stress responses, and virulence in animals, plants, and fungi 4-7. The heme activator protein (HAP) complex, which is also termed nuclear factor Y (NF-Y) or CCAAT-binding factor (CBF), was the first identified and is the most well studied CBC in various eukaryotic organisms. The Saccharomyces cerevisiae Hap complex consists of three essential CCAAT-binding factors (Hap2p, Hap3p, and Hap5p) that are indispensable for CCAAT-binding activity 8,9 , orthologues of which (NF-YA/CBF-B, NF-YB/CBF-A, and NF-YC/ CBF-C, respectively) also comprise the mammalian CCAAT complex (NF-Y/CBF) 10. Core elements of Hap3 and Hap5 display amino acid sequence similarities to the histone fold motifs of histones H2B and H2A, respectively, which are responsible for heterodimeric interactions. Another essential element of the complex, Hap2, contains a subunit association domain that allows for heterotrimer formation and nuclear localization signals (NLS) 11,12. After the assembly of Hap2, Hap3, and Hap5, the heterotrimeric complex then recruits Hap4, an additional compon...

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confidence: 99%

Characterization of the CCAAT-binding transcription factor complex in the plant pathogenic fungus Fusarium graminearum

Kim

Nam

Park

et al. 2020

Sci Rep

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“…Eight hydrophobin genes have been identified in F. verticillioides, HYD1-8 [ 17 , 18 ]. Hydrophobins are a group of small, cysteine-rich proteins expressed in filamentous fungi, which form a hydrophobic/hydrophilic interface on the surface of hyphae and conidia.…”

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confidence: 99%

“…Resistance to hydrogen peroxide was measured as described by Lessing [ 48 ] and Ridenour [ 18 ] with some modifications. Conidia (1 ml of 1 × 10 6 conidia) were mixed with 20 ml of molten PDA and poured into a Petri plate.…”

Section: Methodsmentioning

confidence: 99%

Transcriptome changes in Fusarium verticillioides caused by mutation in the transporter-like gene FST1

2015

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BackgroundFusarium verticillioides causes an important seed disease on maize and produces the fumonisin group of mycotoxins, which are toxic to humans and livestock. A previous study discovered that a gene (FST1) in the pathogen affects fumonisin production and virulence. Although the predicted amino acid sequence of FST1 is similar to hexose transporters, previous experimental evidence failed to prove function.ResultsThree new phenotypes were identified that are associated with the FST1 mutant of F. verticillioides (Δfst1), namely reduction in macroconidia production, increased sensitivity to hydrogen peroxide, and reduced mycelial hydrophobicity. A transcriptome comparison of the wild type and strain Δfst1 grown on autoclaved maize kernels for six days identified 2677 genes that were differentially expressed. Through gene ontology analysis, 961 genes were assigned to one of 12 molecular function categories. Sets of down-regulated genes in strain Δfst1 were identified that could account for each of the mutant phenotypes.ConclusionThe study provides evidence that disruption of FST1 causes several metabolic and developmental defects in F. verticillioides. FST1 appears to connect the expression of several gene networks, including those involved in secondary metabolism, cell wall structure, conidiogenesis, virulence, and resistance to reactive oxygen species. The results support our hypothesis that FST1 functions within the framework of environmental sensing.

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“…following recovery from salt stress. In F. verticillioides , a pathogen of maize stalk rot, environmental stresses including drought have been considered to induces changes in host physiology and to trigger the switch from an asymptomatic endophytic to a virulent pathogenic lifestyle (Ridenour et al, 2014). Enhanced virulence of Fusarium spp.…”

Section: Discussionmentioning

confidence: 99%

Enhanced virulence of Fusarium species associated with spear rot of oil palm following recovery from osmotic stress

2017

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Fusarium spp., which are common inhabitants of oil palm leaves, are weak pathogens of common spear rot (CSR). We investigated the influence of osmotic stress on the growth, virulence, and activity of cell wall-degrading enzymes of CSR fungi, using potato dextrose agar (PDA) supplemented with KCl or sucrose (hyperosmotic medium). Hyperosmotic stress significantly inhibited mycelial growth, but growth rapidly recovered when mycelia were transferred to control medium. When inoculated into oil palm spear leaflets, Fusarium sp., and F. incarnatum precultured on 1.0 and 1.5 M KCl-hyperosmotic medium induced lesions that were two to four times larger than those in non-stressed cultures, suggesting enhanced virulence of the weak pathogens. Lesion size was not greatly affected in hyperosmotic cultures of moderately virulent F. sacchari. No activity of pectin lyase was detected in liquid cultures of the Fusarium isolates. All isolates except F. incarnatum BT48 secreted polygalacturonase (PG), which was active in both liquid cultures and inoculated leaves. Significantly increased PG activity (5–32-fold) was observed on leaves inoculated with hyperosmotic cultures of Fusarium sp. and F. sacchari. These findings suggest that Fusarium sp., F. incarnatum, and F. sacchari exhibit an adaptive physiological plasticity to hyperosmotic stress that results in enhanced virulence.

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The HAP complex in Fusarium verticillioides is a key regulator of growth, morphogenesis, secondary metabolism, and pathogenesis

Cited by 20 publications

References 65 publications

Characterization of the CCAAT-binding transcription factor complex in the plant pathogenic fungus Fusarium graminearum

Characterization of the CCAAT-binding transcription factor complex in the plant pathogenic fungus Fusarium graminearum

Transcriptome changes in Fusarium verticillioides caused by mutation in the transporter-like gene FST1

Enhanced virulence of Fusarium species associated with spear rot of oil palm following recovery from osmotic stress

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