A PLANT VIRUS MODIFIES ROOT VOLATILES TO ATTRACT ITS SOIL NEMATODE
VECTOR TO INFECTED PLANTS
Abstract
Plant derived volatiles mediate interactions between plants, their
pathogenic viruses, and vectors responsible for viral transmission.
These volatile-dependent mechanisms have not been demonstrated
belowground, despite soil organisms being some of the most devastating
agricultural pests. Here we identify a critical component of the signal
used by the plant virus, Tobacco Rattle Virus (TRV) to attract its soil
nematode vector. A significant modification in infected plants was
enhanced 2-ethyl-1-hexanol production. Both nematode chemotaxis and
2-ethyl-1-hexanol production correlated strongly with plant viral load.
Addition of 2-ethyl-1-hexanol to uninfected plants made them
significantly more attractive to nematodes than untreated counterparts.
Removal of TRV RNA-2 genes significantly reduced production of
2-ethyl-1-hexanol and nematode attraction. This work demonstrates, for
the first time, that TRV-driven alterations in root volatile emissions
leads to increased chemotaxis of the virus’s nematode vector, a finding
with implications for sustainable management of both soil nematodes and
viral pathogens in agricultural systems.