Marcelle Johnson

Marcelle Johnson

PhD Candidate


Droevendaalsesteeg 10
6708 PB Wageningen

+31 (0) 317 47 34 00

The Netherlands



I study plant-viral interactions, focused on multipartite virus segment accumulation in hosts. I look at the interplay between host and viral genetic background on infection and evolution by combining greenhouse, wet lab and modelling approaches.


I received my Bachelors and Honours degrees in ecology and environmental conservation from the University of Witwatersrand in South Africa, with a thesis on the cold tolerance strategies of two native alpine plants to the Drakensberg Alpine Centre. My interests in plant ecology, plant molecular biology and evolutionary ecology lead me to complete a Masters in plant biology at the Swedish University of Agricultural Sciences, Sweden. I did my master thesis on barley and cereal yellow dwarf diversity infections in winter cereals (barley, winter wheat and winter rye) in southern Sweden. During this time I did an internship studying the role transcription factors in root stress response to salt and ABA at Uppsala University, and and intensive internship programme in plant breeding on hybrid breeding and developing a breeding programme for African cabbage (cleome gynandra L. ) at the European Plant Breeding College. I started my PhD at the NIOO-KNAW in the department of Microbial Ecology and in the Department of Virology at Wageningen University.

Projecten & samenwerkingen


  • On the evolution of genome segmentation in plant RNA viruses

    Project 2017–2022
    Genome segmentation, the division of the hereditary material into multiple physical units, is widespread across all domains of life. Although many viruses also have segmented genomes, some viruses go a step further and package each segment into a different virus particle.

Additionele Projecten

Unravelling the evolutionary significance of the genome formula of a multipartite virus


Multipartite viruses have segmented genomes, which are individually packaged and transmitted. We study the role and function of the “genome formula”, the host-specific stoichiometric ratio between genome segments, using the model Cucumber mosaic virus. We study the;

    1. Interaction of virus genotype (G) and host (E) on the genome formula
    2. Spatio-temporal GF variability and virus accumulation in local and systemic infections
    3. Experimental evolution of the GF in plant hosts; Nicotiana tabacum, N. benthamiana and Arabidopsis thaliana
    4. Investigate conditions which favour a multipartite strategy and the dis/advantages compared to monopartite and segmented viruses by modelling