Plant virus evolution under strong drought conditions results in a transition from parasitism to mutualism

Significance Viruses are seen as selfish pathogens that harm their hosts to ensure own survival. However, metagenomic studies drawing a new picture in which viruses present everywhere and not always associated diseases. A classic observation plant pathology is the outcome of infection depends on environmental conditions. Here, using experimental evolution, we show relationship between virus its natural host can evolve from pathogenic mutualistic under severe drought While viral strains evolved normal watering conditions increased virulence, drought-evolved confer plants with greater resistance drought. We this transition mutualism complex reorganization hormone-induced signaling pathways changes gene expression.