Abstract

1st year graduate seminar

Aphids transmit cucumber mosaic virus (CMV). In Arabidopsis thaliana infection by the Fny strain of CMV induces aphid feeding deterrence; thought to promote virus transmission. The CMV 2a protein triggers feeding deterrence but another CMV gene product, the 2b RNA silencing suppressor protein, induces stronger, toxicity-based aphid resistance if expressed in transgenic plants. The stronger 2b-induced aphid resistance results from disruption of microRNA (miRNA)-regulated gene expression. Since this stronger form of resistance might be useful in plant protection, I will identify specific miRNA(s) involved in its regulation. I am using the LS CMV strain, which does not induce resistance to aphids in Arabidopsis, as a carrier for ‘decoy’ sequences that mimic miRNA targets and inhibit activity of specific Arabidopsis miRNAs. I have generated a library of LS-CMV variants carrying mimic sequences to identify miRNAs conditioning strong aphid resistance.