Link to home

Candidatus Liberibacter asiaticus Forms ER-Associated Replicative Vacuoles inside Diaphorina citri Gut Cells.

Amit Levy: University of Florida

<div>Citrus greening is caused by the phloem-restricted bacteria <em>Candidatus </em>Liberibacter asiaticus (CLas), and is transmitted by the Asian citrus psyllid (ACP) <em>Diaphorina citri</em>. Current management tools for ACPs rely on the application of chemical insecticides, but at present, these strategies are not efficient enough and also result in insect resistance. Blocking the bacteria propagation and/or movement inside the psyllid can be another alternative to prevent transmission, but very little is currently known about the bacteria-insect interactions. Here we used transmission electron microscopy and confocal microscopy to study the accumulation of CLas inside ACP guts. We show that CLas forms a large replicative vacuole inside the ACP gut cells, and that in the presence of CLas, the psyllid endoplasmic reticulum (ER) undergoes a dramatic re-organization to associate with these intracellular bodies. Immunolocalization confirmed that CLas accumulates inside these vacuoles. Our results suggest that after entry into the gut cells, CLas modifies the host ER to create an isolated and safe environment to support its own propagation inside the psyllid. Understanding the molecular interactions that are involved in this process can open new opportunities for controlling CLas.</div>