Phytopathogens Increase the Preference of Insect Vectors to Volatiles Emitted by Healthy Host Plants.

Phytopathogen infections not only affect the physiology of host plants but also the preference of insect vectors; these modifications may increase the spread of infection. For this, we determined the effects of " Liberibacter asiaticus" (Las) infection on the preference of an insect vector () for its uninfected or Las-infected host () and found that the infected vector preferred uninfected citrus, while the uninfected vector preferred infected citrus. We identified two compounds, ()-3 hexenyl and methyl salicylate, that were differentially abundant in the volatiles emitted by infected and uninfected citrus and two odorant-binding protein (OBP) genes differentially expressed between infected and uninfected vectors. The results of receptor-ligand binding assays indicated that Las upregulated OBP A10 expression in the infected vector to target ()-3 hexenyl acetate emitted by uninfected citrus and induced citrus to emit more methyl salicylate for binding to OBP2 in the uninfected vector. Our results might be useful for the effective control of Las infections.