G-Box Factors 14-3-3 Proteins Negatively Regulate Cucumber Mosaic Virus Infection Tolerance in Arabidopsis

<i>Cucumber mosaic virus</i> (CMV), a representative species of the genus <i>Cucumvirus</i> in the family <i>Bromoviridae</i>, is globally distributed and infects over 1200 monocot and dicot plants. 14-3-3 proteins serve as molecular adaptors that bind phosphorylated target proteins and play significant roles in multiple signaling pathways, including plant growth and development, hormone signaling, and responses to abiotic and biotic stimuli. Although an increasing body of evidence supports the prominent roles of 14-3-3 proteins in regulating plant immunity, their specific roles in plant responses to CMV infection remain unclear. Here, we demonstrate that <i>14-3-3λ</i> and <i>14-3-3κ</i> knockout <i>Arabidopsis</i> plants display enhanced tolerance to CMV infection, with significantly suppressed viral replication compared to wild-type (WT) plants. Additionally, we conducted transcriptomics analysis by comparing the CMV-infected <i>14-3-3λ 14-3-3κ</i> (<i>14-3-3λ/κ</i>) double mutant to the WT using RNA-seq. The KEGG (Kyoto Encyclopedia of Genes and Genomes) enrichment and differentially expressed gene (DEG) results mainly suggest that plant hormone signaling, transcription factor activity, and the autophagy pathway are significantly involved in 14-3-3-mediated CMV tolerance in <i>Arabidopsis</i>. This study reveals new functions and potential molecular mechanisms of 14-3-3 proteins in regulating plant response to CMV infection and provides valuable insights into agricultural production.