Host shifting dynamics in plant viruses and biotechnological frontiers for global food security

Plant viruses account for nearly half of emerging and re-emerging plant disease epidemics, leading to significant crop losses, and are of great concern due to their severe impact on global food security. Host shifting, which results in dead-end infections until viruses completely adapt to the new host enables efficient transmission that can ultimately cause an epidemic. Epidemiological and phylogenetic studies have revealed that host shifting is an intrinsic phenomenon in the evolutionary dynamics of most pathogens. However, researchers are only now beginning to understand the mechanisms that allow pathogens to successfully shift between certain host species while not affecting others. Plant viruses have conserved genetic programming; thus, scientists have observed relatively similar alterations during a new host's plant invasion, thereby, fitness trade-offs yet present a bottleneck in successful host shifting. This provides a potential gateway to assess and manage the risk of emerging viral threats through the development of sophisticated molecular and physiological strategies. In this review, we effort to map molecular mechanisms and epidemiological and anthropogenic factors, driving the host shifting. Furthermore, we examined how evolutionary factors shape patterns of host shifts, plant immune response evasion, and disease emergence, and propose an integrated research modelling to support the management of future plant viral disease epidemics.