About this Research Topic
Plants are grown under adverse conditions of multiple plant viruses in the field, and inevitably, mixed infections are common. Several important virus diseases of plants are the outcomes of interactions between causative viral agents. Most attention in virology research has been given to properties of individual virus species, whereas comparatively little attention has been paid to within-host interactions between viruses in mixed infections. Mixed virus infections in plants usually can exacerbate and increase disease symptoms, significantly increasing crop production losses. The interactions between plant viruses in mixed infections are generally categorized as synergistic, antagonistic or neutral，and these interactions usually create unpredictable biological and epidemiological consequences, threatening global agriculture and our food supplies.
In nature, mixed infections with two or more plant viruses are frequent in the plant, interacting in multiple and intricate ways. Also, there is increasing evidence that mixed viral infections are important in agriculture. The objectives of this Research Topic are to propose new mechanisms underlying the synergistic, antagonistic and neutral interactions in mixed infections of plant viruses. The virus–virus interactions in plants are crucial for understanding viral pathogenesis and evolution and, consequently, developing efficient and stable control strategies in the field. We will also emphasize the severe outcomes of the mixed infection on agriculture, particularly with climate change and increasing extreme weather in recent decades.
The theme of the manuscripts includes (but is not limited to) the following aspects:
• Mixed infections lead to the various intra-host virus–virus interactions, resulting in the generation of variants showing novel genetic features and changing the viral population's genetic structure.
• Mixed infection of plant viruses overcomes plant resistance to a single virus infection. The rapid emergence of virus resistance mutations can result in more virulent virus strains. It will also address the effectiveness of resistance traits in the field under high mix-infection pressure.
• Mixtures of synergistic, antagonistic and neutral (or putatively neutral) interactions, creating usually unpredictable biological and epidemiological consequences, are likely to occur in plants. Therefore, we encourage researchers to report these problems in the field caused by mixed infections.
• Climate change on increasing the occurrence of mixed infection, pathogenesis, insect vector spread and the effect on virus transmission efficiency.
Keywords: Mixed infection, synergistic, antagonistic, pathogenesis, evolution
Important Note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.