capsid-evolution
Capsid evolution refers to the study of how viral coat proteins (capsids) change over time, shaping the diversity, host range, and infectivity of plant viruses. Understanding capsid evolution is critical for plant science because it reveals how viruses adapt to infect new host species, evade plant immune defenses, and spread across agricultural and natural ecosystems. This knowledge informs the development of disease-resistant crops and strategies to limit the spread of damaging plant viral pathogens.
open_in_new WikipediaPubMed · 2026-04-21
Researchers compared the genetic blueprints of plant umbraviruses and related umbra-like viruses, discovering that the protective protein shells (capsids) found in some of these viruses most likely evolved from proteins that originally served a completely different job: helping the virus move between plant cells.
Umbraviruses encode two distinct movement proteins but no capsid protein, making them dependent on helper viruses for insect-mediated transmission to new host plants.
Group 2 umbra-like viruses evolved functional capsid-like proteins that free them from helper-virus dependency, likely enabling independent vector acquisition.
Structural and phylogenetic analyses indicate these capsid-like proteins descended from 30K-type movement proteins, representing a repurposing of cell-to-cell movement machinery into an encapsidation role.
