Interaction between the flagellum of Candidatus Liberibacter asiaticus and the vitellogenin-like protein of Diaphorina citri significantly influences C Las titer.

Huanglongbing (HLB) is a global devastating citrus disease that is mainly caused by " Liberibacter asiaticus" (Las). It is mostly transmitted by the insect Asian citrus psyllid (ACP, ) in a persistent and proliferative manner. Las traverses multiple barriers to complete an infection cycle and is likely involved in multiple interactions with . However, the protein-protein interactions between Las and are largely unknown. Here, we report on a vitellogenin-like protein (Vg_VWD) in that interacts with a Las flagellum (flaA) protein. We found that was upregulated in Las-infected Silencing of in RNAi silencing significantly increased the Las titer, suggesting that plays an important role in the Las interaction. -mediated transient expression assays indicated that Vg_VWD inhibits BAX- and INF1-triggered necrosis and suppresses the callose deposition induced by flaA in . These findings provide new insights into the molecular interaction between Las and .