Autophagy meets plant virology: From molecular crosstalk to outstanding challenges

Autophagy is an evolutionarily conserved degradation and recycling pathway that plays essential roles in plant development, stress adaptation, and immunity. Over the past decade, increasing evidence has revealed that autophagy also shapes the outcome of plant-virus interactions. This review summarizes current understanding of the plant autophagy machinery as well as the experimental approaches used to monitor autophagic flux during viral infection. We then explore the diverse roles of autophagy in the plant-virus interface, highlighting its function as an antiviral mechanism that targets viral components for degradation, and the counterstrategies viruses employ to inhibit or evade this defense. Conversely, some viruses exploit autophagy or its components to facilitate replication, movement, or systemic infection, underscoring its dual nature in plant virology. Recent studies have expanded knowledge of selective autophagy receptors that mediate targeted degradation of viral factors, yet the diversity and specificity of these receptors are likely far from fully characterized. Finally, we discuss outstanding questions such as the mechanisms underlying virus-induced autophagy, the factors determining its switch between antiviral and proviral roles, its crosstalk with other cellular pathways, and the molecular signatures that guide the selective recognition of viral or host proteins. Overall, autophagy emerges as an important regulatory hub in plant-virus interactions, integrating antiviral defense and viral adaptation in a finely tuned balance.