Blocking Aphid Transmission of Cotton Leafroll Dwarf Virus: A New Approach to Disease Management

Cotton leafroll dwarf virus (CLRDV) is an emerging polerovirus threatening cotton production in the US.  Poleroviruses are an important group of insect-transmitted viruses which circulate through their insect vectors as intact virus particles but do not replicate in the insect tissues. The vast majority of poleroviruses are transmitted by aphids, and the likely vector for CLRDV in the US is the cotton aphid. Virus structural proteins are sufficient to facilitate interactions with aphid receptors and regulate plant to plant transmission. In this presentation, we will summarize our molecular research on polerovirus structural proteins, highlighting a novel aphid transmission blocking strategy that was developed to control a related aphid-transmitted polerovirus, Potato leafroll virus (PLRV). A pooled estimate of treatment effects across studies show that aphids are 55% less likely to transmit PLRV following treatment with the transmission inhibitor, with a range of treatment performance from 74% to 20% reduction in transmission in any particular trial. We are working to develop a similar approach for CLRDV that can be used to reduce the spread of CLRDV in cotton fields. We will also discuss the use of virus structural proteins in the development of rapid virus diagnostic tests.