1887

Abstract

The hyd1/hyd2 hydrophobins are important constituents of the conidial cell wall of the insect pathogenic fungus Beauveria bassiana. This fungus can also form intimate associations with several plant species. Here, we show that inactivation of two Class I hydrophobin genes, hyd1 or hyd2, significantly decreases the interaction of B. bassiana with bean roots. Curiously, the ∆hyd1/∆hyd2 double mutant was less impaired in root association than Δhyd1 or Δhyd2. Loss of hyd genes affected growth rate, conidiation ability and oosporein production. Expression patterns for genes involved in conidiation, cell wall integrity, insect virulence, signal transduction, adhesion, hydrophobicity and oosporein production were screened in the deletion mutants grown in different conditions. Repression of the major MAP-Kinase signal transduction pathways (Slt2 MAPK pathway) was observed that was more pronounced in the single versus double hyd mutants under certain conditions. The ∆hyd1/∆hyd2 double mutant showed up-regulation of the Hog1 MAPK and the Msn2 transcription factor under certain conditions when compared to the wild-type or single hyd mutants. The expression of the bad2 adhesin and the oosporein polyketide synthase 9 gene was severely reduced in all of the mutants. On the other hand, fewer changes were observed in the expression of key conidiation and cell wall integrity genes in hyd mutants compared to wild-type. Taken together, the data from this study indicated pleiotropic consequences of deletion of hyd1 and hyd2 on signalling and stress pathways as well as the ability of the fungus to form stable associations with plant roots.

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2018-03-08
2019-10-22
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References

  1. Faria M, Wraight SP. Mycoinsecticides and Mycoacaricides: a comprehensive list with worldwide coverage and international classification of formulation types. Biological Control 2007; 43: 237– 256 [Crossref]
    [Google Scholar]
  2. Glare T, Caradus J, Gelernter W, Jackson T, Keyhani N et al. Have biopesticides come of age?. Trends Biotechnol 2012; 30: 250– 258 [CrossRef] [PubMed]
    [Google Scholar]
  3. Ownley BH, Gwinn KD, Vega FE. Endophytic fungal entomopathogens with activity against plant pathogens: ecology and evolution. BioControl 2010; 55: 113– 128 [CrossRef]
    [Google Scholar]
  4. Sasan RK, Bidochka MJ. The insect-pathogenic fungus Metarhizium robertsii (Clavicipitaceae) is also an endophyte that stimulates plant root development. Am J Bot 2012; 99: 101– 107 [CrossRef] [PubMed]
    [Google Scholar]
  5. Vega FE, Posada F, Catherine Aime M, Pava-Ripoll M, Infante F et al. Entomopathogenic fungal endophytes. Biol Control 2008; 46: 72– 82 [CrossRef]
    [Google Scholar]
  6. Holder DJ, Kirkland BH, Lewis MW, Keyhani NO. Surface characteristics of the entomopathogenic fungus Beauveria (Cordyceps) bassiana. Microbiology 2007; 153: 3448– 3457 [CrossRef] [PubMed]
    [Google Scholar]
  7. Ortiz-Urquiza A, Keyhani NO. Action on the surface: entomopathogenic fungi versus the insect cuticle. Insects 2013; 4: 357– 374 [CrossRef] [PubMed]
    [Google Scholar]
  8. Cole GT, Hoch HC. (editors) The Fungal Spore and Disease Initiation in Plants and Animals New York: Springer Science Business Media; 2013
    [Google Scholar]
  9. Wang C, St Leger RJ. The MAD1 adhesin of Metarhizium anisopliae links adhesion with blastospore production and virulence to insects, and the MAD2 adhesin enables attachment to plants. Eukaryot Cell 2007; 6: 808– 816 [CrossRef] [PubMed]
    [Google Scholar]
  10. Barelli L, Padilla-Guerrero IE, Bidochka MJ. Differential expression of insect and plant specific adhesin genes, Mad1 and Mad2, in Metarhizium robertsii. Fungal Biol 2011; 115: 1174– 1185 [CrossRef] [PubMed]
    [Google Scholar]
  11. Linder MB. Hydrophobins: proteins that self assemble at interfaces. Curr Opin Colloid Interface Sci 2009; 14: 356– 363 [CrossRef]
    [Google Scholar]
  12. Wösten HA. Hydrophobins: multipurpose proteins. Annu Rev Microbiol 2001; 55: 625– 646 [CrossRef] [PubMed]
    [Google Scholar]
  13. Kwan AH, Winefield RD, Sunde M, Matthews JM, Haverkamp RG et al. Structural basis for rodlet assembly in fungal hydrophobins. Proc Natl Acad Sci USA 2006; 103: 3621– 3626 [CrossRef] [PubMed]
    [Google Scholar]
  14. Sunde M, Kwan AH, Templeton MD, Beever RE, Mackay JP. Structural analysis of hydrophobins. Micron 2008; 39: 773– 784 [CrossRef] [PubMed]
    [Google Scholar]
  15. Talbot NJ, Kershaw MJ, Wakley GE, de Vries OMH, Wessels JGH et al. MPGI encodes a fungal hydrophobin involved in surface interactions during infection-related development of Magnaporthe grisea. Plant Cell Am Soc Plant Physiol 1996; 8: 985– 999
    [Google Scholar]
  16. Soanes DM, Kershaw MJ, Cooley RN, Talbot NJ. Regulation of the MPG1 hydrophobin gene in the rice blast fungus Magnaporthe grisea. Mol Plant Microbe Interact 2002; 15: 1253– 1267 [CrossRef] [PubMed]
    [Google Scholar]
  17. Kim S, Ahn IP, Rho HS, Lee YH. MHP1, a Magnaporthe grisea hydrophobin gene, is required for fungal development and plant colonization. Mol Microbiol 2005; 57: 1224– 1237 [CrossRef] [PubMed]
    [Google Scholar]
  18. Dubey MK, Jensen DF, Karlsson M. Hydrophobins are required for conidial hydrophobicity and plant root colonization in the fungal biocontrol agent Clonostachys rosea. BMC Microbiol 2014; 14: 18 [CrossRef] [PubMed]
    [Google Scholar]
  19. Barelli L, Moonjely S, Behie SW, Bidochka MJ. Fungi with multifunctional lifestyles: endophytic insect pathogenic fungi. Plant Mol Biol 2016; 90: 657– 664 [CrossRef] [PubMed]
    [Google Scholar]
  20. Moonjely S, Barelli L, Bidochka MJ. Insect pathogenic fungi as endophytes. Advances in Genetics Academic Press Inc; 2016; pp. 107– 135
    [Google Scholar]
  21. Ortiz-Urquiza A, Keyhani NO. Stress response signaling and virulence: insights from entomopathogenic fungi. Curr Genet 2015; 61: 239– 249 [CrossRef] [PubMed]
    [Google Scholar]
  22. Gibson DM, Donzelli BG, Krasnoff SB, Keyhani NO. Discovering the secondary metabolite potential encoded within entomopathogenic fungi. Nat Prod Rep 2014; 31: 1287– 1305 [CrossRef] [PubMed]
    [Google Scholar]
  23. Ortiz-Urquiza A, Keyhani NO. Molecular genetics of Beauveria bassiana infection of insects. Advances in Genetics Academic Press Inc; 2016; pp. 165– 249
    [Google Scholar]
  24. Valero-Jiménez CA, Wiegers H, Zwaan BJ, Koenraadt CJ, van Kan JA. Genes involved in virulence of the entomopathogenic fungus Beauveria bassiana. J Invertebr Pathol 2016; 133: 41– 49 [CrossRef] [PubMed]
    [Google Scholar]
  25. Zhang S, Xia YX, Kim B, Keyhani NO. Two hydrophobins are involved in fungal spore coat rodlet layer assembly and each play distinct roles in surface interactions, development and pathogenesis in the entomopathogenic fungus, Beauveria bassiana. Mol Microbiol 2011; 80: 811– 826 [CrossRef] [PubMed]
    [Google Scholar]
  26. Wang C, Butt TM, St Leger RJ. Colony sectorization of Metarhizium anisopliae is a sign of ageing. Microbiology 2005; 151: 3223– 3236 [CrossRef] [PubMed]
    [Google Scholar]
  27. Greenfield M, Gómez-Jiménez MI, Ortiz V, Vega FE, Kramer M et al. Beauveria bassiana and Metarhizium anisopliae endophytically colonize cassava roots following soil drench inoculation. Biol Control 2016; 95: 40– 48 [CrossRef] [PubMed]
    [Google Scholar]
  28. Wyrebek M, Huber C, Sasan RK, Bidochka MJ. Three sympatrically occurring species of Metarhizium show plant rhizosphere specificity. Microbiology 2011; 157: 2904– 2911 [CrossRef] [PubMed]
    [Google Scholar]
  29. Ékk F, Keyser CA, Rangel DEN, Foster RN, Roberts DW. CTC medium: A novel dodine-free selective medium for isolating entomopathogenic fungi, especially Metarhizium acridum, from soil. Biol Control 2010; 54: 197– 205 [Crossref]
    [Google Scholar]
  30. Griffin M. Beauveria bassiana, A cotton endophyte with biocontrol activity against seedling disease. Ph.D Dissertation The University of Tennessee, Knoxville, TN, USA:
    [Google Scholar]
  31. Mitchell K, Iadarola MJ. RT-PCR analysis of pain genes: use of gel-based RT-PCR for studying induced and tissue-enriched gene expression. Analgesia: Methods and Protocols pp. 279– 295
    [Google Scholar]
  32. Behie SW, Bidochka MJ. Ubiquity of insect-derived nitrogen transfer to plants by endophytic insect-pathogenic fungi: an additional branch of the soil nitrogen cycle. Appl Environ Microbiol 2014; 80: 1553– 1560 [CrossRef] [PubMed]
    [Google Scholar]
  33. Viterbo A, Chet I. TasHyd1, a new hydrophobin gene from the biocontrol agent Trichoderma asperellum, is involved in plant root colonization. Mol Plant Pathol 2006; 7: 249– 258 [CrossRef] [PubMed]
    [Google Scholar]
  34. Sevim A, Donzelli BG, Wu D, Demirbag Z, Gibson DM et al. Hydrophobin genes of the entomopathogenic fungus, Metarhizium brunneum, are differentially expressed and corresponding mutants are decreased in virulence. Curr Genet 2012; 58: 79– 92 [CrossRef] [PubMed]
    [Google Scholar]
  35. Whiteford JR, Lacroix H, Talbot NJ, Spanu PD. Stage-specific cellular localisation of two hydrophobins during plant infection by the pathogenic fungus Cladosporium fulvum. Fungal Genet Biol 2004; 41: 624– 634 [CrossRef] [PubMed]
    [Google Scholar]
  36. Feng P, Shang Y, Cen K, Wang C. Fungal biosynthesis of the bibenzoquinone oosporein to evade insect immunity. Proc Natl Acad Sci USA 2015; 112: 11365– 11370 [CrossRef] [PubMed]
    [Google Scholar]
  37. Fan Y, Liu X, Keyhani NO, Tang G, Pei Y et al. Regulatory cascade and biological activity of Beauveria bassiana oosporein that limits bacterial growth after host death. Proc Natl Acad Sci USA 2017; 114: E1578 E1586 [CrossRef] [PubMed]
    [Google Scholar]
  38. Xiao G, Ying SH, Zheng P, Wang ZL, Zhang S et al. Genomic perspectives on the evolution of fungal entomopathogenicity in Beauveria bassiana. Sci Rep 2012; 2: 483 [CrossRef] [PubMed]
    [Google Scholar]
  39. Luo Z, Ren H, Mousa JJ, Rangel DE, Zhang Y et al. The PacC transcription factor regulates secondary metabolite production and stress response, but has only minor effects on virulence in the insect pathogenic fungus Beauveria bassiana. Environ Microbiol 2017; 19: 788– 802 [CrossRef] [PubMed]
    [Google Scholar]
  40. Chen X, Xu C, Qian Y, Liu R, Zhang Q et al. MAPK cascade-mediated regulation of pathogenicity, conidiation and tolerance to abiotic stresses in the entomopathogenic fungus Metarhizium robertsii. Environ Microbiol 2016; 18: 1048– 1062 [CrossRef] [PubMed]
    [Google Scholar]
  41. Luo X, Keyhani NO, Yu X, He Z, Luo Z et al. The MAP kinase Bbslt2 controls growth, conidiation, cell wall integrity, and virulence in the insect pathogenic fungus Beauveria bassiana. Fungal Genet Biol 2012; 49: 544– 555 [CrossRef] [PubMed]
    [Google Scholar]
  42. Huang S, He Z, Zhang S, Keyhani NO, Song Y et al. Interplay between calcineurin and the Slt2 MAP-kinase in mediating cell wall integrity, conidiation and virulence in the insect fungal pathogen Beauveria bassiana. Fungal Genet Biol 2015; 83: 78– 91 [CrossRef] [PubMed]
    [Google Scholar]
  43. Zhang Y, Zhao J, Fang W, Zhang J, Luo Z et al. Mitogen-activated protein kinase hog1 in the entomopathogenic fungus Beauveria bassiana regulates environmental stress responses and virulence to insects. Appl Environ Microbiol 2009; 75: 3787– 3795 [CrossRef] [PubMed]
    [Google Scholar]
  44. He Z, Zhang S, Keyhani NO, Song Y, Huang S et al. A novel mitochondrial membrane protein, Ohmm, limits fungal oxidative stress resistance and virulence in the insect fungal pathogen Beauveria bassiana. Environ Microbiol 2015; 17: 4213– 4238 [CrossRef] [PubMed]
    [Google Scholar]
  45. Yang Q, Yin D, Yin Y, Cao Y, Ma Z. The response regulator BcSkn7 is required for vegetative differentiation and adaptation to oxidative and osmotic stresses in Botrytis cinerea. Mol Plant Pathol 2015; 16: 276– 287 [CrossRef] [PubMed]
    [Google Scholar]
  46. Rui O, Hahn M. The Slt2-type MAP kinase Bmp3 of Botrytis cinerea is required for normal saprotrophic growth, conidiation, plant surface sensing and host tissue colonization. Mol Plant Pathol 2007; 8: 173– 184 [CrossRef] [PubMed]
    [Google Scholar]
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