Marilyn J. Roossinck, Ph.D.

  • Professor, Plant Pathology and Environmental Microbiology, and Biology
  • Sir Walter Murdoch Adjunct Professor, Murdoch University, Perth, Western Australia
Marilyn J. Roossinck, Ph.D.
Center for Infectious Disease Dynamics
W229A Millennium Science Complex
The Pennsylvania State University

University Park, PA 16802
Work Phone: 814-865-2292
Fax: 814-863-7217

Areas of Expertise

  • Adaptation to extreme environments with microbes


  1. Ph.D., University of Colorado School of Medicine

Areas of Interest:

Our focus in the Roossinck lab is on virus-plant and virus-fungus-plant interactions in virus evolution and ecology.  

We use Cucumber mosaic virus (CMV) as a model virus for experimental evolution studies, including generation and maintenance of quasispecies, rates of recombination, and polymerase fidelity.

We are interested in how plants use viruses in adaptation to extreme environments. Fungal viruses are involved in plants adapting to geothermal soils in Yellowstone National Park, and acute plant viruses confer drought and cold tolerance to plants.  We are studying the mechanisms of these interactions.

We are interested in the biodiversity of plant viruses.  We are studying viruses in wild plants in Costa Rica using next-gen sequence analysis of viral RNA from individual plants.  To date we have collected about 14,000 plants and have analyzed about half of them.

Recent Publications:

Roossinck, Marilyn J. Virus: An Illustrated Guide to 101 Incredible Microbes. Princeton, NJ: Princeton University Press, 2016.

Research papers:

Thapa, V., G.G. Turner, S. Hafenstein, B.E. Overton, K.J. Vanderwolf, M.J. Roossinck. 2016. Using a novel partitivirus in Pseudogymnoascus destructans to understand the epidemiology of white-nose syndrome. PLOS Pathogens 12:e1006076.

Min, B.-E., T.S. Feldman, A. Ali, G. Wiley, V. Muthukumar,  B.A. Roe, M. J. Roossinck, U. Melcher, M. W. Palmer, R. S. Nelson. 2012. Cloning, ecological and epidemiological analysis of a novel tymovirus in Asclepias viridis from Oklahoma. Phytopathology 102:166-176. 

Stobbe, A.H.,  U. Melcher, M.W. Palmer, M. J. Roossinck, and G. Shen. 2012.  Co-divergence and host-switching in the evolution of tobamoviruses.  J. Gen. Virol. 93:408-418.

Feldman, T.S., M.R. Morsy, and M. J. Roossinck. 2012.  Are communities of microbial symbionts more diverse than communities of macrobial hosts? Fungal Biology 116: 465-477.

Thapa, V.  U. Melcher, G. B. Wiley, A. Doust, M. W. Palmer, K. Roewe, B. A. Roe, G. Shen, and M. J. Roossinck. 2012.  Detection of Members of the Secoviridae in the Tallgrass Prairie Preserve, Osage County, Oklahoma USA Virus Res. 167:34-42.

Xu, P. H. Wang, F. Coker, J-Y Ma, Y. Tang, ME Taylor and MJ Roossinck 2012.  Genetic loci controlling lethal cell death in tomato caused by viral satellite RNA infection.  Mol. Plant-Microbe Interact. 25:1034-1044

Pita, J. S., and M. J. Roossinck.  2013. Mapping viral functional domains for genetic diversity in plants. J. Virol. 87:790-797

Pita, J.S. and M.J. Roossinck. 2013. Fixation of emerging inter-viral recombinants in Cucumber mosaic virus populations is controlled by the replicase. J. Virol. 87:1264-1269

MacDiarmid, R., B. Rodoni, U. Melcher, F. Ochoa-Corona, and M.J. Roossinck. 2013. Biosecurity implications of new technology in plant virus research. PLoS Pathogens 9:8

Du, Z., A. Chen, W. Chen, Q. Liao, H. Zhang, Y. Bao, M.J. Roossinck, and J.P. Carr. 2014.  Nuclearcytoplasmic partitioning of Cucumber mosaic virus protein 2b determines the balance between its roles as a virulence determinant and an RNA-silencing suppressor. J. Virol. 88:5228-5241.

Peyambari, M., M.K. Habibi, K-B. Fotouhifar, A Dizadji, and M.J. Roossinck. 2014.  Molecular characterization of a novel putative partitivurs infecting Cytospora sacchari, a plant pathogenic fungus.  Plant Pathol. J. 30:151-158.


Roossinck, M. J. 2012.  Viruses can be our friends.  Microbiol. Today. 39:100-103.

Roossinck, M. J. 2012.  Even viruses can be beneficial microbes.  Microbiol. Australia 33: 111-112

Márquez, L. M. and M. J. Roossinck. 2012.  Do persistent viruses fit the trade-off hypothesis of virulence evolution?  Curr. Op. Virol. 2:556-560.

Roossinck, M. J. 2012. Plant virus metagenomics:  Biodiversity and ecology.  Ann. Rev. Genetics 46:357-367.

Roossinck, M. J. 2012. Persistent Plant Viruses:  Molecular Hitchhikers or Epigenetic Elements?  In Viruses:  Essential Agents of Life. pp 177-186.

Rodriguez, R.J., and M.J. Roossinck. 2012. Viruses, fungi and plants:  Cross-Kingdom Communication and Mutualism. in Biocommunication of Fungi, pp. 219-227

Bao, X., and M. J. Roossinck. 2013. Multiplexed interactions:  viruses of endophytic fungi. Adv. in Virus Res. Adv. in Virus Res.  86:37-57.

Roossinck, M.J. 2013. Plant Virus Ecology. PLoS Pathogens 9(5): e1003304

Bao, X., and M. J. Roossinck. 2013.  A Life History View of Mutualistic Viral Symbioses: Quantity or Quality for Cooperation?  Curr. Op. Microbiol., 16:514-518.

Stobbe, A.H. and M.J. Roossinck. 2014.  Plant Virus Metagenomics:  what we know and why we need to know more.  Frontiers in Plant Science 5:e150.

Safari, M. and M. J. Roossinck. 2014.  How does the genome structure and lifestyle of a virus affect its population variation?  Curr. Op Virology 9:39-44

Roossinck, M.J. 2014.  Metagenomics of plant and fungal viruses reveals an abundance of persistent lifestyles. Frontiers in Microbiology 5:e787.