EniGma · Elucidation of dynamics and impact of geminivirus-induced reorganization of cellular chromatin

Viruses are obligate parasites that manipulate host proteins and structures to complete their life cycle and cause devastating diseases in animals and plants, impacting global health, food security, and economies. Some DNA viruses that target nucleus as their site of replication can induce drastic changes in the nuclear architecture termed “reorganization of cellular chromatin” (ROCC). ROCC is characterized by condensation and margination of host chromatin. It has been observed in infections by five different DNA virus families with hosts across kingdoms. Given the polyphyletic origins of these virus families, ROCC is suggested to result from a convergently evolved viral infection strategy. However, despite its wide incidence, how ROCC starts, proceeds, and impacts host and virus is yet to be fully explored. Here, we propose to characterize the dynamics and impact of ROCC on virus and host during geminivirus infection in plants, using confocal microscopy and laser microdissection combined with omics approach. Firstly, we will track and define phenotypes of ROCC phases by imaging host chromatin. Secondly, we will monitor the localizations of host and viral DNA as well as proteins associated with viral life cycle during ROCC. Finally, we will isolate the nuclei at different phases of ROCC by laser microdissection and analyze phase-specific nuclear transcriptomics, chromatin accessibility and conformation, as well as proteomics. Together, the results from this project will shed light on the spatiotemporal dynamics and significance of nuclear reorganization induced by geminiviruses. Characterizing ROCC may lead not only to the deeper understanding of the nuclear viral replication mechanism but also to new crop breeding strategies for resistance against geminiviruses. Ultimately, the results may also contribute to new therapeutic strategies against important animal-infecting viruses that also induce ROCC.