Srk1 kinase, a SR protein-specific kinase, is important for sexual reproduction, plant infection and pre-mRNA processing in Fusarium graminearum

Fusarium graminearum is an important pathogen of small grains and maize in many areas of the world. Infected grains are often contaminated with mycotoxins harmful to humans and animals. During the past decade, F. graminearum has caused several severe epidemics of head scab in wheat and barley. In order to understand molecular mechanisms regulating fungal development and pathogenicity in this pathogen, we isolated and characterized a MAP kinase gene, MGV1, which is highly homologous to the MPS1 gene in Magnaporthe grisea. The MGV1 gene was dispensable for conidiation in F. graminearum but essential for female fertility during sexual reproduction. Vegetative growth of mgv1 deletion mutants was normal in liquid media but reduced on solid media. Mycelia of the mgv1 mutants had weak cell walls and were hypersensitive to cell wall degrading enzymes. Interestingly, the mgv1 mutants were self-incompatible when tested for heterokaryon formation, and their virulence was substantially reduced. The ability of the mutants to accumulate trichothecene mycotoxins on inoculated wheat was also greatly reduced. Our data suggest that MGV1 in F. graminearum is involved in multiple developmental processes related to sexual reproduction, plant infection, and cell wall integrity.

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FgSfl1 and Its Conserved PKA Phosphorylation Sites Are Important for Conidiation, Sexual Reproduction, and Pathogenesis in Fusarium graminearum

Journal of Fungi ◽

10.3390/jof7090755 ◽

2021 ◽

Vol 7 (9) ◽

pp. 755

Author(s):

Chen Gong ◽

Junqi Huang ◽

Daiyuan Sun ◽

Daiying Xu ◽

Yuqian Guo ◽

...

Keyword(s):

Sexual Reproduction ◽

Fusarium Graminearum ◽

Double Mutant ◽

Deletion Mutant ◽

Phosphorylation Site ◽

Phosphorylation Sites ◽

Catalytic Subunits ◽

Cellular Processes ◽

Plant Infection ◽

Dependent Protein

The fungal plant pathogen, Fusarium graminearum, contains two genes, FgCPK1 and FgCPK2, encoding the catalytic subunits of cAMP-dependent protein kinase A. FgCPK1 and FgCPK2 are responsible for most of the PKA activities and have overlapping functions in various cellular processes in F. graminearum. The cpk1 cpk2 double mutant was significantly reduced in growth, rarely produced conidia, and was non-pathogenic. In this study, we found that the cpk1 cpk2 double mutant was unstable and produced fast-growing spontaneous sectors that were defective in plant infection. All spontaneous suppressor strains had mutations in FgSFL1, a transcription factor gene orthologous to SFL1 in yeast. Thirteen suppressor strains had non-sense mutations at Q501, three suppressor strains had frameshift mutations at W198, and five suppressor strains had mutations in the HSF binding domain of FgSfl1. Only one suppressor strain had both a non-synonymous mutation at H225 and a non-sense mutation at R490. We generated the SFL1 deletion mutant and found that it produced less than 2% of conidia than that of the wild-type strain PH-1. The sfl1 mutant was significantly reduced in the number of perithecia on carrot agar plates at 7 days post-fertilization (dpf). When incubated for more than 12 days, ascospore cirrhi were observed on the sfl1 mutant perithecia. The infection ability of the sfl1 deletion mutant was also obviously defective. Furthermore, we found that in addition to the S223 and S559 phosphorylation sites, FgSFL1 had another predicted phosphorylation site: T452. Interestingly, the S223 phosphorylation site was responsible for sexual reproduction, and the T452 phosphorylation site was responsible for growth and sexual reproduction. Only the S559 phosphorylation site was found to play an important role in conidiation, sexual reproduction, and infection. Overall, our results indicate that FgSFL1 and its conserved PKA phosphorylation sites are important for vegetative growth, conidiation, sexual reproduction, and pathogenesis in F. graminearum.

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The cyclase-associated protein FgCap1 has both protein kinase A-dependent and -independent functions during deoxynivalenol production and plant infection in Fusarium graminearum

Molecular Plant Pathology ◽

10.1111/mpp.12540 ◽

2017 ◽

Vol 19 (3) ◽

pp. 552-563 ◽

Cited By ~ 18

Author(s):

Tao Yin ◽

Qiang Zhang ◽

Jianhua Wang ◽

Huiquan Liu ◽

Chenfang Wang ◽

...

Keyword(s):

Protein Kinase ◽

Protein Kinase A ◽

Fusarium Graminearum ◽

Plant Infection ◽

Independent Functions ◽

Kinase A

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FgSsn3 kinase, a component of the mediator complex, is important for sexual reproduction and pathogenesis in Fusarium graminearum

Scientific Reports ◽

10.1038/srep22333 ◽

2016 ◽

Vol 6 (1) ◽

Cited By ~ 11

Author(s):

Shulin Cao ◽

Shijie Zhang ◽

Chaofeng Hao ◽

Huiquan Liu ◽

Jin-Rong Xu ◽

...

Keyword(s):

Sexual Reproduction ◽

Fusarium Graminearum ◽

Mediator Complex ◽

Kinase A

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Opposing functions of Fng1 and the Rpd3 HDAC complex in H4 acetylation in Fusarium graminearum

PLoS Genetics ◽

10.1371/journal.pgen.1009185 ◽

2020 ◽

Vol 16 (11) ◽

pp. e1009185

Author(s):

Hang Jiang ◽

Aliang Xia ◽

Meng Ye ◽

Jingyi Ren ◽

Dongao Li ◽

...

Keyword(s):

Growth Rate ◽

Sexual Reproduction ◽

Fusarium Graminearum ◽

Essential Gene ◽

Head Blight ◽

Altered Expression ◽

Expression Levels ◽

Growth Defects ◽

Plant Infection ◽

Severe Growth

Histone acetylation, balanced by histone acetyltransferase (HAT) and histone deacetylase (HDAC) complexes, affects dynamic transitions of chromatin structure to regulate transcriptional accessibility. However, little is known about the interplay between HAT and HDAC complexes in Fusarium graminearum, a causal agent of Fusarium Head Blight (FHB) that uniquely contains chromosomal regions enriched for house-keeping or infection-related genes. In this study, we identified the ortholog of the human inhibitor of growth (ING1) gene in F. graminearum (FNG1) and found that it specifically interacts with the FgEsa1 HAT of the NuA4 complex. Deletion of FNG1 led to severe growth defects and blocked conidiation, sexual reproduction, DON production, and plant infection. The fng1 mutant was normal in H3 acetylation but significantly reduced in H4 acetylation. A total of 34 spontaneous suppressors of fng1 with faster growth rate were isolated. Most of them were still defective in sexual reproduction and plant infection. Thirty two of them had mutations in orthologs of yeast RPD3, SIN3, and SDS3, three key components of the yeast Rpd3L HDAC complex. Four mutations in these three genes were verified to suppress the defects of fng1 mutant in growth and H4 acetylation. The rest two suppressor strains had a frameshift or nonsense mutation in a glutamine-rich hypothetical protein that may be a novel component of the FgRpd3 HDAC complex in filamentous fungi. FgRpd3, like Fng1, localized in euchromatin. Deletion of FgRPD3 resulted in severe growth defects and elevated H4 acetylation. In contract, the Fgsds3 deletion mutant had only a minor reduction in growth rate but FgSIN3 appeared to be an essential gene. RNA-seq analysis revealed that 48.1% and 54.2% of the genes with altered expression levels in the fng1 mutant were recovered to normal expression levels in two suppressor strains with mutations in FgRPD3 and FgSDS3, respectively. Taken together, our data showed that Fng1 is important for H4 acetylation as a component of the NuA4 complex and functionally related to the FgRpd3 HDAC complex for transcriptional regulation of genes important for growth, conidiation, sexual reproduction, and plant infection in F. graminearum.

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A novel antisense long noncoding RNA participates in asexual and sexual reproduction by regulating the expression of GzmetE in Fusarium graminearum

Environmental Microbiology ◽

10.1111/1462-2920.15399 ◽

2021 ◽

Author(s):

Jie Wang ◽

Wenping Zeng ◽

Jiatao Xie ◽

Yanping Fu ◽

Daohong Jiang ◽

...

Keyword(s):

Sexual Reproduction ◽

Fusarium Graminearum ◽

Long Noncoding Rna ◽

Noncoding Rna

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The cAMP-PKA Pathway Regulates Growth, Sexual and Asexual Differentiation, and Pathogenesis in Fusarium graminearum

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-10-13-0306-r ◽

2014 ◽

Vol 27 (6) ◽

pp. 557-566 ◽

Cited By ~ 48

Author(s):

Shuai Hu ◽

Xiaoying Zhou ◽

Xiaoying Gu ◽

Shulin Cao ◽

Chengfang Wang ◽

...

Keyword(s):

Fusarium Graminearum ◽

Vegetative Growth ◽

Double Mutant ◽

Elevated Temperatures ◽

Hyphal Growth ◽

Growth Defects ◽

Plant Infection ◽

Dependent Protein ◽

Pka Pathway

Like many other filamentous ascomycetes, Fusarium graminearum contains two genes named CPK1 and CPK2 that encode the catalytic subunits of cyclic AMP (cAMP)-dependent protein kinase A (PKA). To determine the role of cAMP signaling in pathogenesis and development in F. graminearum, we functionally characterized these two genes. In addition, we generated and characterized the cpk1 cpk2 double and fac1 adenylate cyclase gene deletion mutants. The cpk1 mutant was significantly reduced in vegetative growth, conidiation, and deoxynivalenol production but it had increased tolerance to elevated temperatures. It was defective in the production of penetration branches on plant surfaces, colonization of wheat rachises, and spreading in flowering wheat heads. Deletion of CPK1 had no effect on perithecium development but the cpk1 mutant was defective in ascospore maturation and releasing. In contrast, the cpk2 mutant had no detectable phenotypes, suggesting that CPK2 contributes minimally to PKA activities in F. graminearum. Nevertheless, the cpk1 cpk2 double mutant had more severe defects in vegetative growth and rarely produced morphologically abnormal conidia. The double mutant, unlike the cpk1 or cpk2 mutant, was nonpathogenic and failed to form perithecia on self-mating plates. Therefore, CPK1 and CPK2 must have overlapping functions in vegetative growth, differentiation, and plant infection in F. graminearum. The fac1 mutant was also nonpathogenic and had growth defects similar to those of the cpk1 cpk2 mutant. However, deletion of FAC1 had no effect on conidium morphology. These results indicated that CPK1 is the major PKA catalytic subunit gene and that the cAMP-PKA pathway plays critical roles in hyphal growth, conidiation, ascosporogenesis, and plant infection in F. graminearum.

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