1
|
Huang Z, Wu D, Yang S, Fu W, Ma D, Yao Y, Lin H, Yuan J, Yang Y, Zhuang Z. Regulation of Fungal Morphogenesis and Pathogenicity of Aspergillus flavus by Hexokinase AfHxk1 through Its Domain Hexokinase_2. J Fungi (Basel) 2023; 9:1077. [PMID: 37998882 PMCID: PMC10671980 DOI: 10.3390/jof9111077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 10/28/2023] [Accepted: 11/02/2023] [Indexed: 11/25/2023] Open
Abstract
As a filamentous pathogenic fungus with high-yield of aflatoxin B1, Aspergillus flavus is commonly found in various agricultural products. It is crucial to develop effective strategies aimed at the prevention of the contamination of A. flavus and aflatoxin. Hexokinase AfHxk1 is a critical enzyme in fungal glucose metabolism. However, the role of AfHxk1 in A. flavus development, aflatoxin biosynthesis, and virulence has not yet been explored. In this study, afHxk1 gene deletion mutant (ΔafHxk1), complementary strain (Com-afHxk1), and the domain deletion strains (afHxk1ΔD1 and afHxk1ΔD2) were constructed by homologous recombination. Phenotype study and RT-qPCR revealed that AfHxk1 upregulates mycelium growth and spore and sclerotia formation, but downregulates AFB1 biosynthesis through related classical signaling pathways. Invading models and environmental stress analysis revealed that through involvement in carbon source utilization, conidia germination, and the sensitivity response of A. flavus to a series of environmental stresses, AfHxk1 deeply participates in the regulation of pathogenicity of A. flavus to crop kernels and Galleria mellonella larvae. The construction of domain deletion strains, afHxk1ΔD1 and afHxk1ΔD2, further revealed that AfHxk1 regulates the morphogenesis, mycotoxin biosynthesis, and the fungal pathogenicity mainly through its domain, Hexokinase_2. The results of this study revealed the biological role of AfHxk1 in Aspergillus spp., and might provide a novel potential target for the early control of the contamination of A. flavus.
Collapse
Affiliation(s)
- Zongting Huang
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, Proteomic Research Center, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (Z.H.); (D.W.); (S.Y.); (W.F.); (Y.Y.); (H.L.); (J.Y.); (Y.Y.)
| | - Dandan Wu
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, Proteomic Research Center, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (Z.H.); (D.W.); (S.Y.); (W.F.); (Y.Y.); (H.L.); (J.Y.); (Y.Y.)
| | - Sile Yang
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, Proteomic Research Center, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (Z.H.); (D.W.); (S.Y.); (W.F.); (Y.Y.); (H.L.); (J.Y.); (Y.Y.)
| | - Wangzhuo Fu
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, Proteomic Research Center, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (Z.H.); (D.W.); (S.Y.); (W.F.); (Y.Y.); (H.L.); (J.Y.); (Y.Y.)
| | - Dongmei Ma
- College of Animal Sciences (College of Bee Science), Fujian Agriculture and Forestry University, Fuzhou 350002, China;
| | - Yanfang Yao
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, Proteomic Research Center, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (Z.H.); (D.W.); (S.Y.); (W.F.); (Y.Y.); (H.L.); (J.Y.); (Y.Y.)
| | - Hong Lin
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, Proteomic Research Center, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (Z.H.); (D.W.); (S.Y.); (W.F.); (Y.Y.); (H.L.); (J.Y.); (Y.Y.)
| | - Jun Yuan
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, Proteomic Research Center, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (Z.H.); (D.W.); (S.Y.); (W.F.); (Y.Y.); (H.L.); (J.Y.); (Y.Y.)
| | - Yanling Yang
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, Proteomic Research Center, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (Z.H.); (D.W.); (S.Y.); (W.F.); (Y.Y.); (H.L.); (J.Y.); (Y.Y.)
| | - Zhenhong Zhuang
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, Proteomic Research Center, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (Z.H.); (D.W.); (S.Y.); (W.F.); (Y.Y.); (H.L.); (J.Y.); (Y.Y.)
| |
Collapse
|
2
|
Gan T, An H, Tang M, Chen H. Establishment of RNA Interference Genetic Transformation System and Functional Analysis of FlbA Gene in Leptographium qinlingensis. Int J Mol Sci 2023; 24:13009. [PMID: 37629189 PMCID: PMC10455979 DOI: 10.3390/ijms241613009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2023] [Revised: 08/17/2023] [Accepted: 08/19/2023] [Indexed: 08/27/2023] Open
Abstract
Leptographium qinlingensis is a pathogenic fungus of Pinus armandii that is epidemic in the Qinling Mountains. However, an effective gene interference strategy is needed to characterize the pathogenic genes in this fungus on a functional level. Using the RNA silencing vector pSilent-1 as a template, we established an RNA interference genetic transformation system mediated by Agrobacterium tumefaciens GV3101, which is suitable for the gene study for Leptographium qinlingensis by homologous recombination and strain interference system screening. The LqFlbA gene was silenced using the RNA interference approach described above, and the resulting transformants displayed various levels of silencing with a gene silencing effectiveness ranging from 41.8% to 91.4%. The LqFlbA-RNAi mutant displayed altered colony morphology, sluggish mycelium growth, and diminished pathogenicity toward the host P. armandii in comparison to the wild type. The results indicate that this method provides a useful reverse genetic system for studying the gene function of L. qinlingensis, and that LqFlbA plays a crucial role in the growth, development, and pathogenicity of L. qinlingensis.
Collapse
Affiliation(s)
| | | | | | - Hui Chen
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou 510642, China (H.A.); (M.T.)
| |
Collapse
|
3
|
Schalamun M, Molin EM, Schmoll M. RGS4 impacts carbohydrate and siderophore metabolism in Trichoderma reesei. BMC Genomics 2023; 24:372. [PMID: 37400774 PMCID: PMC10316542 DOI: 10.1186/s12864-023-09467-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 06/20/2023] [Indexed: 07/05/2023] Open
Abstract
BACKGROUND Adaptation to complex, rapidly changing environments is crucial for evolutionary success of fungi. The heterotrimeric G-protein pathway belongs to the most important signaling cascades applied for this task. In Trichoderma reesei, enzyme production, growth and secondary metabolism are among the physiological traits influenced by the G-protein pathway in a light dependent manner. RESULTS Here, we investigated the function of the SNX/H-type regulator of G-protein signaling (RGS) protein RGS4 of T. reesei. We show that RGS4 is involved in regulation of cellulase production, growth, asexual development and oxidative stress response in darkness as well as in osmotic stress response in the presence of sodium chloride, particularly in light. Transcriptome analysis revealed regulation of several ribosomal genes, six genes mutated in RutC30 as well as several genes encoding transcription factors and transporters. Importantly, RGS4 positively regulates the siderophore cluster responsible for fusarinine C biosynthesis in light. The respective deletion mutant shows altered growth on nutrient sources related to siderophore production such as ornithine or proline in a BIOLOG phenotype microarray assay. Additionally, growth on storage carbohydrates as well as several intermediates of the D-galactose and D-arabinose catabolic pathway is decreased, predominantly in light. CONCLUSIONS We conclude that RGS4 mainly operates in light and targets plant cell wall degradation, siderophore production and storage compound metabolism in T. reesei.
Collapse
Affiliation(s)
- Miriam Schalamun
- AIT Austrian Institute of Technology GmbH, Bioresources Unit, Center for Health & Bioresources, Konrad Lorenz Strasse 24, Tulln, 3430 Austria
| | - Eva Maria Molin
- AIT Austrian Institute of Technology GmbH, Bioresources Unit, Center for Health & Bioresources, Konrad Lorenz Strasse 24, Tulln, 3430 Austria
| | - Monika Schmoll
- AIT Austrian Institute of Technology GmbH, Bioresources Unit, Center for Health & Bioresources, Konrad Lorenz Strasse 24, Tulln, 3430 Austria
- Division of Terrestrial Ecosystem Research, Centre of Microbiology and Ecosystem Science, University of Vienna, Djerassiplatz 1, Vienna, 1030 Austria
| |
Collapse
|
4
|
Cho HJ, Son SH, Chen W, Son YE, Lee I, Yu JH, Park HS. Regulation of Conidiogenesis in Aspergillus flavus. Cells 2022; 11:cells11182796. [PMID: 36139369 PMCID: PMC9497164 DOI: 10.3390/cells11182796] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 08/29/2022] [Accepted: 09/06/2022] [Indexed: 11/16/2022] Open
Abstract
Aspergillus flavus is a representative fungal species in the Aspergillus section Flavi and has been used as a model system to gain insights into fungal development and toxin production. A. flavus has several adverse effects on humans, including the production of the most carcinogenic mycotoxin aflatoxins and causing aspergillosis in immune-compromised patients. In addition, A. flavus infection of crops results in economic losses due to yield loss and aflatoxin contamination. A. flavus is a saprophytic fungus that disperses in the ecosystem mainly by producing asexual spores (conidia), which also provide long-term survival in the harsh environmental conditions. Conidia are composed of the rodlet layer, cell wall, and melanin and are produced from an asexual specialized structure called the conidiophore. The production of conidiophores is tightly regulated by various regulators, including the central regulatory cascade composed of BrlA-AbaA-WetA, the fungi-specific velvet regulators, upstream regulators, and developmental repressors. In this review, we summarize the findings of a series of recent studies related to asexual development in A. flavus and provide insights for a better understanding of other fungal species in the section Flavi.
Collapse
Affiliation(s)
- He-Jin Cho
- School of Food Science and Biotechnology, Kyungpook National University, Daegu 41566, Korea
| | - Sung-Hun Son
- School of Food Science and Biotechnology, Kyungpook National University, Daegu 41566, Korea
| | - Wanping Chen
- Department of Molecular Microbiology and Genetics, University of Göttingen, 37077 Göttingen, Germany
| | - Ye-Eun Son
- School of Food Science and Biotechnology, Kyungpook National University, Daegu 41566, Korea
| | - Inhyung Lee
- Department of Bio and Fermentation Convergence Technology, Kookmin University, Seoul 02707, Korea
| | - Jae-Hyuk Yu
- Department of Bacteriology, University of Wisconsin, Madison, WI 53706, USA
- Department of Systems Biotechnology, Konkuk University, Seoul 05029, Korea
| | - Hee-Soo Park
- School of Food Science and Biotechnology, Kyungpook National University, Daegu 41566, Korea
- Department of Integrative Biology, Kyungpook National University, Daegu 41566, Korea
- Correspondence: ; Tel.: +82-53-950-5751
| |
Collapse
|
5
|
Gan T, An H, Tang M, Chen H. Phylogeny of Regulators of G-Protein Signaling Genes in Leptographium qinlingensis and Expression Levels of Three RGSs in Response to Different Terpenoids. Microorganisms 2022; 10:microorganisms10091698. [PMID: 36144299 PMCID: PMC9506272 DOI: 10.3390/microorganisms10091698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 08/16/2022] [Accepted: 08/22/2022] [Indexed: 11/16/2022] Open
Abstract
Leptographium qinlingensis is a bark beetle-vectored pine pathogen in the Chinese white pine beetle (Dendroctonus armandi) epidemic in Northwest China. L. qinlingensis colonizes pines despite the trees’ massive oleoresin terpenoid defenses. Regulators of G-protein signaling (RGS) proteins modulate heterotrimeric G-protein signaling negatively and play multiple roles in the growth, asexual development, and pathogenicity of fungi. In this study, we have identified three L. qinlingensis RGS genes, and the phylogenetic analysis shows the highest homology with the regulators of G-protein signaling proteins sequence from Ophiostoma piceae and Grosmannia clavigera. The expression profiles of three RGSs in the mycelium of L. qinlingensis treated with six different terpenoids were detected, as well as their growth rates. Under six terpenoid treatments, the growth and reproduction in L. qinlingensis were significantly inhibited, and the growth inflection day was delayed from 8 days to 12–13 days. By analyzing the expression level of three RGS genes of L. qinlingensis with different treatments, results indicate that LqFlbA plays a crucial role in controlling fungal growth, and both LqRax1 and LqRgsA are involved in overcoming the host chemical resistances and successful colonization.
Collapse
Affiliation(s)
| | | | | | - Hui Chen
- Correspondence: ; Tel.: +86-135-1911-6730
| |
Collapse
|
6
|
Gil-Sánchez MDM, Cea-Sánchez S, Luque EM, Cánovas D, Corrochano LM. Light regulates the degradation of the regulatory protein VE-1 in the fungus Neurospora crassa. BMC Biol 2022; 20:149. [PMID: 35761233 PMCID: PMC9238092 DOI: 10.1186/s12915-022-01351-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 06/15/2022] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Fungi use light as an environmental signal to regulate developmental transitions that are key aspects of their biological cycles and that are also relevant for their dispersal and infectivity as plant or animal pathogens. In addition, light regulates the accumulation of photoprotective pigments, like carotenoids, and other secondary metabolites. Most fungal light responses occur after changes in gene transcription and we describe here a novel effect of light in the regulation of degradation of VE-1, a key component of the velvet complex, in the model fungus Neurospora crassa. The velvet complex is a fungal-specific protein complex that coordinates fungal development, secondary metabolism, and light regulation by interacting with other regulators and photoreceptors and modifying gene expression. RESULTS We have characterized the role of VE-1 during conidiation in N. crassa. In vegetative mycelia, VE-1 is localized in the cytoplasm and nuclei and is required for light-dependent transcription but does not interact with the photoreceptor and transcription factor WC-1. VE-1 is more stable in light than in darkness during asexual development (conidiation). We have shown that this light effect requires the blue-light photoreceptor WC-1. We have characterized the role of the proteasome, the COP9 signalosome (CSN), and the adaptor component of cullin-RING ubiquitin ligases, FWD-1, in the degradation of VE-1. CONCLUSIONS We propose that this new effect of light allows the fungal cell to adapt quickly to changes in light exposure by promoting the accumulation of VE-1 for the regulation of genes that participate in the biosynthesis of photoprotective pigments.
Collapse
Affiliation(s)
| | - Sara Cea-Sánchez
- Departamento de Genética, Universidad de Sevilla, Reina Mercedes s/n, 41012, Seville, Spain
| | - Eva M Luque
- Departamento de Genética, Universidad de Sevilla, Reina Mercedes s/n, 41012, Seville, Spain
| | - David Cánovas
- Departamento de Genética, Universidad de Sevilla, Reina Mercedes s/n, 41012, Seville, Spain
| | - Luis M Corrochano
- Departamento de Genética, Universidad de Sevilla, Reina Mercedes s/n, 41012, Seville, Spain.
| |
Collapse
|
7
|
Yuan XY, Li JY, Zhi QQ, Chi SD, Qu S, Luo YF, He ZM. SfgA Renders Aspergillus flavus More Stable to the External Environment. J Fungi (Basel) 2022; 8:jof8060638. [PMID: 35736121 PMCID: PMC9224668 DOI: 10.3390/jof8060638] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Revised: 06/07/2022] [Accepted: 06/08/2022] [Indexed: 02/04/2023] Open
Abstract
sfgA is known as a key negative transcriptional regulator gene of asexual sporulation and sterigmatocystin production in Aspergillus nidulans. However, here, we found that the homolog sfgA gene shows a broad and complex regulatory role in governing growth, conidiation, sclerotia formation, secondary metabolism, and environmental stress responses in Aspergillus flavus. When sfgA was deleted in A. flavus, the fungal growth was slowed, but the conidiation was significantly increased, and the sclerotia formation displayed different behavior at different temperatures, which increased at 30 °C but decreased at 36 °C. In addition, sfgA regulated aflatoxin biosynthesis in a complex way that was associated with the changes in cultured conditions, and the increased production of aflatoxin in the ∆sfgA mutant was associated with a decrease in sclerotia size. Furthermore, the ∆sfgA mutant exhibited sensitivity to osmotic, oxidative, and cell wall stresses but still produced dense conidia. Transcriptome data indicated that numerous development- and secondary-metabolism-related genes were expressed differently when sfgA was deleted. Additionally, we also found that sfgA functions downstream of fluG in A. flavus, which is consistent with the genetic position in FluG-mediated conidiation in A. nidulans. Collectively, sfgA plays a critical role in the development, secondary metabolism, and stress responses of A. flavus, and sfgA renders A. flavus more stable to the external environment.
Collapse
Affiliation(s)
- Xiao-Yu Yuan
- The Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Science, Sun Yat-sen University, Guangzhou 510275, China; (X.-Y.Y.); (J.-Y.L.); (Q.-Q.Z.); (S.-D.C.); (S.Q.)
| | - Jie-Ying Li
- The Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Science, Sun Yat-sen University, Guangzhou 510275, China; (X.-Y.Y.); (J.-Y.L.); (Q.-Q.Z.); (S.-D.C.); (S.Q.)
| | - Qing-Qing Zhi
- The Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Science, Sun Yat-sen University, Guangzhou 510275, China; (X.-Y.Y.); (J.-Y.L.); (Q.-Q.Z.); (S.-D.C.); (S.Q.)
- College of Agriculture and Biology, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, China
| | - Sheng-Da Chi
- The Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Science, Sun Yat-sen University, Guangzhou 510275, China; (X.-Y.Y.); (J.-Y.L.); (Q.-Q.Z.); (S.-D.C.); (S.Q.)
| | - Su Qu
- The Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Science, Sun Yat-sen University, Guangzhou 510275, China; (X.-Y.Y.); (J.-Y.L.); (Q.-Q.Z.); (S.-D.C.); (S.Q.)
| | - Yan-Feng Luo
- Guangdong Jinyinshan Environmental Protection Technology Co., Ltd., Guangzhou 510705, China;
| | - Zhu-Mei He
- The Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Science, Sun Yat-sen University, Guangzhou 510275, China; (X.-Y.Y.); (J.-Y.L.); (Q.-Q.Z.); (S.-D.C.); (S.Q.)
- Correspondence:
| |
Collapse
|
8
|
Regulator of G Protein Signaling Contributes to the Development and Aflatoxin Biosynthesis in Aspergillus flavus through the Regulation of Gα Activity. Appl Environ Microbiol 2022; 88:e0024422. [PMID: 35638847 PMCID: PMC9238415 DOI: 10.1128/aem.00244-22] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Heterotrimeric G-proteins play crucial roles in growth, asexual development, and pathogenicity of fungi. The regulator of G-protein signaling (RGS) proteins function as negative regulators of the G proteins to control the activities of GTPase in Gα subunits. In this study, we functionally characterized the six RGS proteins (i.e., RgsA, RgsB, RgsC, RgsD, RgsE, and FlbA) in the pathogenic fungus Aspergillus flavus. All the aforementioned RGS proteins were also found to be functionally different in conidiation, aflatoxin (AF) biosynthesis, and pathogenicity in A. flavus. Apart from FlbA, all other RGS proteins play a negative role in regulating both the synthesis of cyclic AMP (cAMP) and the activation of protein kinase A (PKA). Additionally, we also found that although RgsA and RgsE play a negative role in regulating the FadA-cAMP/PKA pathway, they function distinctly in aflatoxin biosynthesis. Similarly, RgsC is important for aflatoxin biosynthesis by negatively regulating the GanA-cAMP/PKA pathway. PkaA, which is the cAMP-dependent protein kinase catalytic subunit, also showed crucial influences on A. flavus phenotypes. Overall, our results demonstrated that RGS proteins play multiple roles in the development, pathogenicity, and AF biosynthesis in A. flavus through the regulation of Gα subunits and cAMP-PKA signals. IMPORTANCE RGS proteins, as crucial regulators of the G protein signaling pathway, are widely distributed in fungi, while little is known about their roles in Aspergillus flavus development and aflatoxin. In this study, we identified six RGS proteins in A. flavus and revealed that these proteins have important functions in the regulation of conidia, sclerotia, and aflatoxin formation. Our findings provide evidence that the RGS proteins function upstream of cAMP-PKA signaling by interacting with the Gα subunits (GanA and FadA). This study provides valuable information for controlling the contamination of A. flavus and mycotoxins produced by this fungus in pre- and postharvest of agricultural crops.
Collapse
|
9
|
FFGA1 Protein Is Essential for Regulating Vegetative Growth, Cell Wall Integrity, and Protection against Stress in Flammunina filiformis. J Fungi (Basel) 2022; 8:jof8040401. [PMID: 35448632 PMCID: PMC9030616 DOI: 10.3390/jof8040401] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2022] [Revised: 04/09/2022] [Accepted: 04/12/2022] [Indexed: 01/25/2023] Open
Abstract
Flammulina filiformis is a popular mushroom which has been regarded as a potential model fungus for mycelium growth, fruiting body development, and stress response studies. Based on a genome-wide search, four genes encoding heterotrimeric G protein α subunits were identified in F. filiformis. The data of conserved domain analysis showed that these genes contain only one subgroup I of Gα subunit (Gαi), similar to many other fungi. To explore the function of Gαi, FfGa1 over-expression (OE) and RNA interference (RNAi) strains were generated using the Agrobacterium tumefaciens-mediated transformation (ATMT) approach. RNAi strains showed remarkably reduced growth on PDA medium and sensitivity to cell wall-perturbing agents, with maximum growth inhibition, but showed better growth in response to hypertonic stress-causing agents, while OE strains exhibited more resistance to thermal stress and mycoparasite Trichoderma as compared to the wild-type and RNAi strains. Taken together, our results indicated that FfGa1 positively regulates hyphal extension, and is crucial for the maintenance of cell wall integrity and protection against biotic and abiotic (hypertonic and thermal) stress.
Collapse
|
10
|
Ma N, Jiang KX, Bai N, Li DN, Zhang KQ, Yang JK. Functional Analysis of Two Affinity cAMP Phosphodiesterases in the Nematode-Trapping Fungus Arthrobotrys oligospora. Pathogens 2022; 11:pathogens11040405. [PMID: 35456080 PMCID: PMC9026129 DOI: 10.3390/pathogens11040405] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 03/22/2022] [Accepted: 03/25/2022] [Indexed: 01/27/2023] Open
Abstract
Phosphodiesterases are essential regulators of cyclic nucleotide signaling with diverse physiological functions. Two phosphodiesterases, PdeH and PdeL, have been identified from yeast and filamentous fungi. Here, the orthologs of PdeH and PdeL were characterized in a typical nematode-trapping fungus Arthrobotrys oligospora by gene disruption and phenotypic comparison. Deletion of AopdeH caused serious defects in mycelial growth, conidiation, stress response, trap formation, and nematicidal efficiency compared to the wild-type strain. In contrast, these phenotypes have no significant difference in the absence of AopdeL. In addition, deletion of AopdeH and AopdeL resulted in a remarkable increase in cAMP level during vegetative growth and trap formation, and the number of autophagosomes was decreased in ΔAopdeH and ΔAopdeL mutants, whereas their volumes considerably increased. Moreover, metabolomic analyses revealed that many metabolites were downregulated in ΔAopdeH mutant compared to their expression in the wild-type strain. Our results indicate that AoPdeH plays a crucial role in mycelial growth, conidiation, stress response, secondary metabolism, and trap formation. In contrast, AoPdeL only plays a minor role in hyphal and conidial morphology, autophagy, and trap formation in A. oligospora. This work expands the roles of phosphodiesterases and deepens the understanding of the regulation of trap formation in nematode-trapping fungi.
Collapse
Affiliation(s)
- Ni Ma
- State Key Laboratory for Conservation and Utilization of Bio-Resources, Key Laboratory for Microbial Resources of the Ministry of Education, School of Life Sciences, Yunnan University, Kunming 650091, China; (N.M.); (K.-X.J.); (N.B.); (D.-N.L.); (K.-Q.Z.)
- Yunnan Center for Disease Control and Prevention, Kunming 650022, China
| | - Ke-Xin Jiang
- State Key Laboratory for Conservation and Utilization of Bio-Resources, Key Laboratory for Microbial Resources of the Ministry of Education, School of Life Sciences, Yunnan University, Kunming 650091, China; (N.M.); (K.-X.J.); (N.B.); (D.-N.L.); (K.-Q.Z.)
| | - Na Bai
- State Key Laboratory for Conservation and Utilization of Bio-Resources, Key Laboratory for Microbial Resources of the Ministry of Education, School of Life Sciences, Yunnan University, Kunming 650091, China; (N.M.); (K.-X.J.); (N.B.); (D.-N.L.); (K.-Q.Z.)
| | - Dong-Ni Li
- State Key Laboratory for Conservation and Utilization of Bio-Resources, Key Laboratory for Microbial Resources of the Ministry of Education, School of Life Sciences, Yunnan University, Kunming 650091, China; (N.M.); (K.-X.J.); (N.B.); (D.-N.L.); (K.-Q.Z.)
| | - Ke-Qin Zhang
- State Key Laboratory for Conservation and Utilization of Bio-Resources, Key Laboratory for Microbial Resources of the Ministry of Education, School of Life Sciences, Yunnan University, Kunming 650091, China; (N.M.); (K.-X.J.); (N.B.); (D.-N.L.); (K.-Q.Z.)
| | - Jin-Kui Yang
- State Key Laboratory for Conservation and Utilization of Bio-Resources, Key Laboratory for Microbial Resources of the Ministry of Education, School of Life Sciences, Yunnan University, Kunming 650091, China; (N.M.); (K.-X.J.); (N.B.); (D.-N.L.); (K.-Q.Z.)
- Correspondence:
| |
Collapse
|
11
|
Fierro F, Vaca I, Castillo NI, García-Rico RO, Chávez R. Penicillium chrysogenum, a Vintage Model with a Cutting-Edge Profile in Biotechnology. Microorganisms 2022; 10:573. [PMID: 35336148 PMCID: PMC8954384 DOI: 10.3390/microorganisms10030573] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 02/15/2022] [Accepted: 02/17/2022] [Indexed: 12/20/2022] Open
Abstract
The discovery of penicillin entailed a decisive breakthrough in medicine. No other medical advance has ever had the same impact in the clinical practise. The fungus Penicillium chrysogenum (reclassified as P. rubens) has been used for industrial production of penicillin ever since the forties of the past century; industrial biotechnology developed hand in hand with it, and currently P. chrysogenum is a thoroughly studied model for secondary metabolite production and regulation. In addition to its role as penicillin producer, recent synthetic biology advances have put P. chrysogenum on the path to become a cell factory for the production of metabolites with biotechnological interest. In this review, we tell the history of P. chrysogenum, from the discovery of penicillin and the first isolation of strains with high production capacity to the most recent research advances with the fungus. We will describe how classical strain improvement programs achieved the goal of increasing production and how the development of different molecular tools allowed further improvements. The discovery of the penicillin gene cluster, the origin of the penicillin genes, the regulation of penicillin production, and a compilation of other P. chrysogenum secondary metabolites will also be covered and updated in this work.
Collapse
Affiliation(s)
- Francisco Fierro
- Departamento de Biotecnología, Universidad Autónoma Metropolitana-Unidad Iztapalapa, Ciudad de México 09340, Mexico
| | - Inmaculada Vaca
- Departamento de Química, Facultad de Ciencias, Universidad de Chile, Santiago 7800003, Chile;
| | - Nancy I. Castillo
- Grupo de Investigación en Ciencias Biológicas y Químicas, Facultad de Ciencias, Universidad Antonio Nariño, Bogotá 110231, Colombia;
| | - Ramón Ovidio García-Rico
- Grupo de Investigación GIMBIO, Departamento De Microbiología, Facultad de Ciencias Básicas, Universidad de Pamplona, Pamplona 543050, Colombia;
| | - Renato Chávez
- Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago 9170020, Chile;
| |
Collapse
|
12
|
Role of Two G-Protein α Subunits in Vegetative Growth, Cell Wall Integrity, and Virulence of the Entomopathogenic Fungus Metarhizium robertsii. J Fungi (Basel) 2022; 8:jof8020132. [PMID: 35205884 PMCID: PMC8877820 DOI: 10.3390/jof8020132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 01/26/2022] [Accepted: 01/27/2022] [Indexed: 02/05/2023] Open
Abstract
Heterotrimeric G-proteins are crucial for fungal growth and differentiation. The α subunits of heterotrimeric G-proteins play an essential role in controlling signal transduction. However, the function of G-protein α subunits in entomopathogenic fungi remains poorly understood. Two group II Gα subunits (MrGPA2 and MrGPA4) were characterized in the entomopathogenic fungus, Metarhizium robertsii. Bioinformatics analysis showed that the relationship between MrGPA2 and MrGPA4 was closer than that of other MrGPAs. Both green fluorescent protein (GFP)-tagged MrGPA2 and MrGPA4 were localized at the cytoplasm. Furthermore, ∆MrGpa2∆MrGpa4 double mutants showed remarkably reduced vegetative growth compared to the wild-type and single-mutant strains, which was accompanied by the downregulation of several growth-related genes, such as ssk2, pbs2, stuA, hog1, and ac. Only the ∆MrGpa2∆MrGpa4 double mutant was sensitive to Congo red stress. The insect bioassay demonstrated significantly attenuated virulence for the ∆MrGpa2∆MrGpa4 double mutant compared to the wild-type and single-mutant strains. Further analysis indicated that double deletion of MrGpa2 and MrGpa4 had no effect on appressorium formation but suppressed the expression levels of several virulence-related genes in the insect hemocoel. These findings demonstrate that MrGpa2 and MrGpa4 exhibit functional redundancy and contribute to the vegetative growth, stress tolerance, and pest control potential in M. robertsii.
Collapse
|
13
|
The Toxic Mechanism of Gliotoxins and Biosynthetic Strategies for Toxicity Prevention. Int J Mol Sci 2021; 22:ijms222413510. [PMID: 34948306 PMCID: PMC8705807 DOI: 10.3390/ijms222413510] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 12/09/2021] [Accepted: 12/13/2021] [Indexed: 12/13/2022] Open
Abstract
Gliotoxin is a kind of epipolythiodioxopiperazine derived from different fungi that is characterized by a disulfide bridge. Gliotoxins can be biosynthesized by a gli gene cluster and regulated by a positive GliZ regulator. Gliotoxins show cytotoxic effects via the suppression the function of macrophage immune function, inflammation, antiangiogenesis, DNA damage by ROS production, peroxide damage by the inhibition of various enzymes, and apoptosis through different signal pathways. In the other hand, gliotoxins can also be beneficial with different doses. Low doses of gliotoxin can be used as an antioxidant, in the diagnosis and treatment of HIV, and as an anti-tumor agent in the future. Gliotoxins have also been used in the control of plant pathogens, including Pythium ultimum and Sclerotinia sclerotiorum. Thus, it is important to elucidate the toxic mechanism of gliotoxins. The toxic mechanism of gliotoxins and biosynthetic strategies to reduce the toxicity of gliotoxins and their producing strains are summarized in this review.
Collapse
|
14
|
Ma N, Zhao Y, Wang Y, Yang L, Li D, Yang J, Jiang K, Zhang KQ, Yang J. Functional analysis of seven regulators of G protein signaling (RGSs) in the nematode-trapping fungus Arthrobotrys oligospora. Virulence 2021; 12:1825-1840. [PMID: 34224331 PMCID: PMC8259722 DOI: 10.1080/21505594.2021.1948667] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 06/06/2021] [Accepted: 06/18/2021] [Indexed: 01/09/2023] Open
Abstract
Regulators of G protein signaling (RGSs) are proteins that negatively regulate G protein signal transduction. In this study, seven putative RGSs were characterized in the nematode-trapping (NT) fungus, Arthrobotrys oligospora. Deleting Rgs genes significantly increased intracellular cAMP levels, and caused defects in mycelia growth, stress resistance, conidiation, trap formation, and nematocidal activity. In particular, the ΔAoFlbA mutant was unable to produce conidia and traps. Transcriptomic analysis showed that amino acid metabolic and biosynthetic processes were significantly enriched in the ΔAoFlbA mutant compared to WT. Interestingly, Gas1 family genes are significantly expanded in A. oligospora and other NT fungi that produce adhesive traps, and are differentially expressed during trap formation in A. oligospora. Disruption of two Gas1 genes resulted in defective conidiation, trap formation, and pathogenicity. Our results indicate that RGSs play pleiotropic roles in regulating A. oligospora mycelial growth, development, and pathogenicity. Further, AoFlbA is a prominent member and required for conidiation and trap formation, possibly by regulating amino acid metabolism and biosynthesis. Our results provide a basis for elucidating the signaling mechanism of vegetative growth, lifestyle transition, and pathogenicity in NT fungi.
Collapse
Affiliation(s)
- Ni Ma
- State Key Laboratory for Conservation and Utilization of Bio-Resources, and Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, KunmingP. R. China
- School of Life Sciences, Yunnan University, KunmingP. R. China
| | - Yining Zhao
- State Key Laboratory for Conservation and Utilization of Bio-Resources, and Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, KunmingP. R. China
- School of Life Sciences, Yunnan University, KunmingP. R. China
| | - Yunchuan Wang
- State Key Laboratory for Conservation and Utilization of Bio-Resources, and Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, KunmingP. R. China
- Institute of Medical Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, KunmingP. R. China
| | - Le Yang
- State Key Laboratory for Conservation and Utilization of Bio-Resources, and Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, KunmingP. R. China
- School of Life Sciences, Yunnan University, KunmingP. R. China
| | - Dongni Li
- State Key Laboratory for Conservation and Utilization of Bio-Resources, and Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, KunmingP. R. China
- School of Life Sciences, Yunnan University, KunmingP. R. China
| | - Jiangliu Yang
- State Key Laboratory for Conservation and Utilization of Bio-Resources, and Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, KunmingP. R. China
- School of Life Sciences, Yunnan University, KunmingP. R. China
| | - Kexin Jiang
- State Key Laboratory for Conservation and Utilization of Bio-Resources, and Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, KunmingP. R. China
- School of Life Sciences, Yunnan University, KunmingP. R. China
| | - Ke-Qin Zhang
- State Key Laboratory for Conservation and Utilization of Bio-Resources, and Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, KunmingP. R. China
- School of Life Sciences, Yunnan University, KunmingP. R. China
| | - Jinkui Yang
- State Key Laboratory for Conservation and Utilization of Bio-Resources, and Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, KunmingP. R. China
- School of Life Sciences, Yunnan University, KunmingP. R. China
| |
Collapse
|
15
|
Zhu H, Liu D, Zheng L, Chen L, Ma A. Characterization of a G protein α subunit encoded gene from the dimorphic fungus-Tremella fuciformis. Antonie van Leeuwenhoek 2021; 114:1949-1960. [PMID: 34510304 DOI: 10.1007/s10482-021-01653-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 09/02/2021] [Indexed: 11/26/2022]
Abstract
Tremella fuciformis is a dimorphic fungus which can undertake the reversible transition between yeast and pseudohypha forms. G protein α subunit (Gα) carries different signals to regulate a variety of biological processes in eukaryotes, including fungal dimorphism. In this study, a novel Gα subunit encoded gene, TrGpa1, was firstly cloned from T. fuciformis. The TrGpa1 open reading frame has 1059 nucleotides, and encodes a protein which belongs to the group I of Gαi superfamily. Furthermore, the role of TrGpa1 in the T. fuciformis dimorphism was analysed by gene overexpression and knockdown. Stable integration of the target gene into the genome was confirmed by PCR and Southern blot hybridization. Transformants with the highest and lowest TrGpa1 expression levels were selected via quantitative real-time PCR analysis and Western blot. Each transformant was compared with the wild-type strain about the morphological change under different environmental factors, including pH values, temperature, cultivation time, inoculum size, and quorum-sensing molecules (farnesol and tyrosol). Comparing with the wild-type strain, the overexpression transformant always had higher ratios of pseudohyphae, while the knockdown transformant had less proportions of pseudohyphae. Therefore, the TrGpa1 is involved in the dimorphism of T. fuciformis and plays a positive role in promoting pseudohyphal growth.
Collapse
Affiliation(s)
- Hanyu Zhu
- College of Life Science and Environment, Hengyang Normal University, Hengyang, 421000, China
- College of Food Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Dongmei Liu
- College of Food Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Liesheng Zheng
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Liguo Chen
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Aimin Ma
- College of Food Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China.
- Key Laboratory of Agro-Microbial Resources and Utilization, Ministry of Agriculture, Huazhong Agricultural University, Wuhan, 430070, China.
| |
Collapse
|
16
|
Bourret RB, Kennedy EN, Foster CA, Sepúlveda VE, Goldman WE. A Radical Reimagining of Fungal Two-Component Regulatory Systems. Trends Microbiol 2021; 29:883-893. [PMID: 33853736 DOI: 10.1016/j.tim.2021.03.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Revised: 03/08/2021] [Accepted: 03/09/2021] [Indexed: 11/17/2022]
Abstract
Bacterial two-component regulatory systems (TCSs) mediate signal transduction by transferring phosphoryl groups between sensor kinase and response regulator proteins, sometimes using intermediary histidine-phosphotransferase (Hpt) domains to form multistep phosphorelays. Because (i) almost all known fungal sensor kinases exhibit a domain architecture characteristic of bacterial TCS phosphorelays, (ii) all known fungal Hpts are stand-alone proteins suited to shuttle between cytoplasm and nucleus, and (iii) the best-characterized fungal TCS is a canonical phosphorelay, it is widely assumed that most or all fungal TCSs function via phosphorelays. However, fungi generally encode more sensor kinases than Hpts or response regulators, leading to a disparity between putative phosphorelay inputs and outputs. The simplest resolution of this paradox is to hypothesize that most fungal sensor kinases do not participate in phosphorelays. Reimagining how fungal TCSs might function leads to multiple testable predictions.
Collapse
Affiliation(s)
- Robert B Bourret
- Department of Microbiology & Immunology, University of North Carolina, Chapel Hill, NC 27599-7290, USA.
| | - Emily N Kennedy
- Department of Microbiology & Immunology, University of North Carolina, Chapel Hill, NC 27599-7290, USA
| | - Clay A Foster
- Department of Microbiology & Immunology, University of North Carolina, Chapel Hill, NC 27599-7290, USA
| | - Victoria E Sepúlveda
- Department of Microbiology & Immunology, University of North Carolina, Chapel Hill, NC 27599-7290, USA
| | - William E Goldman
- Department of Microbiology & Immunology, University of North Carolina, Chapel Hill, NC 27599-7290, USA
| |
Collapse
|