Begomoviruses, which belong to the Geminiviridae family, are intracellular parasites transmitted by whiteflies to dicotyledonous plants thatsignificantly damage agronomically relevant crops. These nucleus-replicating DNA viruses move intracellularly from the nucleus to the cytoplasm and then, like other plant viruses, cause disease by spreading systemically throughout the plant. The transport proteins of begomoviruses play a crucial role in recruiting host components for the movement of viral DNA within and between cells, while exhibiting functions that suppress the host’s immune defense. Pioneering studies on species of the Begomovirus genus have identified specific viral transport proteins involved in intracellular transport, cell-to-cell movement, and systemic spread. Recent research has primarily focused on viral movement proteins and their interactions with the cellular host transport machinery, which has significantly expanded understanding on viral infection pathways. This review focuses on three components within this context: (i) the role of viral transport proteins, specifically movement proteins (MPs) and nuclear shuttle proteins (NSPs), (ii) their ability to recruit host factors for intra- and intercellular viral movement, and (iii) the suppression of antiviral immunity, with a particular emphasis on bipartite begomoviral movement proteins.

Photosynthesis and translation are targets of metabolic control and development in plants, yet how stress signals coordinately regulate these opposing energy-producing and consuming processes remains enigmatic. Here, we unravel a growth control circuit that ties photosynthesis to translational control in response to biotic and abiotic signals. Our findings reveal that the L10-INTERACTING MYB DOMAIN-CONTAINING PROTEIN (LIMYB), a key player of the NUCLEAR SHUTTLE PROTEIN-INTERACTING KINASE 1 (NIK1)/ RIBOSOMAL PROTEIN L10 (RPL10) antiviral signaling pathway, not only downregulates translation genes, but also represses photosynthesis-related genes and photosynthesis itself. LIMYB repressor activity, regulated by phosphorylation, is crucial for the decline in photosynthesis under stress. NIK1 activation by PAMPs or the phosphomimetic NIK1-T474D represses photosynthesis-related genes and photosynthesis in control but not in limyb lines. Furthermore, heat and osmotic stress also activate the NIK1/RPL10/LIMYB signaling circuit in wild type. These stresses induce NIK1 phosphorylation, but not marker gene repression, in limyb, indicating that LIMYB connects NIK1 activation to stress-mediated downregulation of translation- and photosynthesis-related genes. This coordinated repression via the NIK1/RPL10/LIMYB module may help plants adapt to changing environments.

Begomoviruses, which belong to the Geminiviridae family, are intracellular parasites transmitted by whiteflies to dicotyledonous plants, significantly damaging agronomically relevant crops. These nucleus-replicating DNA viruses need to move intracellularly from the nucleus to the cytoplasm and then, like other plant viruses, spread systemically throughout the plant to cause dis-ease. The transport proteins of begomoviruses play a crucial role in recruiting host components for the movement of viral DNA within and between cells while exhibiting functions that suppress the host's immune defense. Pioneering studies on species of the Begomovirus genus have identified specific viral transport proteins involved in intracellular transport, cell-to-cell movement, and systemic spread. Recent research has primarily focused on viral movement proteins and their interaction with the cellular host transport machinery, significantly expanding our understanding of viral infection pathways. This review focuses on three main aspects: (i) the role of viral transport proteins, specifically movement proteins (MPs) and nuclear shuttle proteins (NSPs), (ii) their ability to recruit host factors for intra- and intercellular viral movement, and (iii) suppress antiviral immunity, with a particular emphasis on bipartite begomoviral movement proteins.