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POSTERS: Molecular/Cellular Plant‐Microbe Interactions II

P-360 - SUMOylation of the ToLCNDV-OM movement protein contributes to the promotion of systemic viral dissemination and mechanical transmission

Tuesday, August 5, 2025
10:15 AM - 11:00 AM HST
Location: Exhibit Hall 3

    Author(s)

  • CT

    Choon Meng Tan

    Department of Plant Pathology, National Chung Hsing University
    Taichung, Taichung, Taiwan (Republic of China)

  • CY

    Che-Ssu Yang

    Department of Plant Pathology, National Chung Hsing University
    Taichung, Taichung, Taiwan (Republic of China)

  • CL

    Chia-Hwa Lee

    Department of Plant Pathology, National Chung Hsing University
    Taichung, Taichung, Taiwan (Republic of China)

  • HC

    Ho-Hsiung Chang

    Assistant Professor
    Department of Plant Pathology, National Chung Hsing University
    Taichung, Taichung, Taiwan (Republic of China)

    • Presenting Author(s)

  • FJ

    Fuh-Jyh Jan

    Professor
    Department of Plant Pathology, National Chung Hsing University
    Taichung, Taichung, Taiwan (Republic of China)

Abstract Text: Plant-virus interactions involve complex communications between plant and viral factors. Due to the limited coding capacity, viruses must hijack specific cellular pathways of hosts, including post-translational modification systems, for their infection and propagation. Recent studies have shown that proteins from plant viruses can undergo SUMO conjugation, which facilitates viral replication and systemic movement. In this study, we identified potential SUMOylation sites and SUMO-interacting motifs within the movement protein (MP, BC1) of the tomato leaf curl New Delhi virus-oriental melon isolate (ToLCNDV-OM). Our analysis revealed lysine residues at positions 43 and 159 as SUMOylation targets, along with a SUMO-interacting motif located between residues 74-77 in the MP. ToLCNDV-MPOM(K43A), MPOM(K159A) and MPOM(K43/159A) mutants induced attenuated symptoms on Nicotiana benthamiana plants. qPCR analysis corroborated a reduction in viral DNA accumulation in systemic leaves of the mutant viruses infected plants. Protoplast transfection assays confirmed that viral replication remained unaffected by these mutations, suggesting that MP SUMOylation is specifically associated with viral cell-to-cell or systemic movement. Moreover, we observed that the ToLCNDV-MPOM(K43A), MPOM(K159A), and MPOM(K43/159A) mutants showed diminished mechanical transmission efficiency in N. benthamiana. Both in vivo and in vitro SUMOylation assays validated the SUMOylation on the MP of ToLCNDV-OM. Taken together, our findings reveal that SUMOylation of the MP protein is critical for ToLCNDV infection.