AI Summary
Barley yellow striate mosaic virus (BYSMV) infects the central nervous system of the small brown planthopper, inducing hyperactivity and prolonging feeding. BYSMV's accessory protein interacts with a specific subunit in the planthopper's CNS and disrupts circadian rhythm, resulting in high locomotor activity. This suggests that BYSMV modulates the behavior of insect vectors to facilitate transmission.
Transmission of many plant viruses relies on phloem-feeding insect vectors. However, how plant viruses directly modulate insect behavior is largely unknown. Barley yellow striate mosaic virus (BYSMV) is transmitted by the small brown planthopper (SBPH, Laodelphax striatellus). Here, we show that BYSMV infects the central nervous system (CNS) of SBPHs, induces insect hyperactivity, and prolongs phloem feeding duration. The BYSMV accessory protein P6 interacts with the COP9 signalosome subunit 5 (LsCSN5) of SBPHs and suppresses LsCSN5-regulated de-neddylation from the Cullin 1 (CUL1), hereby inhibiting CUL1-based E3 ligases-mediated degradation of the circadian clock protein Timeless (TIM). Thus, virus infection or knockdown of LsCSN5 compromises TIM oscillation and induces high insect locomotor activity for transmission. Additionally, expression of BYSMV P6 in the CNS of transgenic Drosophila melanogaster disturbs circadian rhythm and induces high locomotor activity. Together, our results suggest the molecular mechanisms whereby BYSMV modulates locomotor activity of insect vectors for transmission.
Insects are vectors of many parasites causing various diseases in animals and plants. Increasing evidence has demonstrated that these parasites have evolved diverse effectors to modulate insect behaviors for their horizontal spread in nature1. Transmission of insect-borne plant pathogens including viruses, fungi, bacteria, and phytoplasmas