Subcellular localization of putative Candidatus Liberibacter asiaticus effectors in plant species.

TORRES P.; GADEA J.; MOLINA M.C.; REDES J.; VOJNOV A.A.; GARCIA L.; AGOSTINI J.P.; MARANO M.R.

Foz do Iguaçu

Congreso; International Citrus Congress 2016; 2018

Huanglongbing (HLB) is the most destructive disease of Citrus spp. Its causal agent is a gram negative and phloem- inhabiting bacterium, Candidatus Liberibacter spp., being Liberibacter asiaticus (CLas), the most prevalent specie around the world. The bacterium can be transmitted by graft- ing, dodder or psyllid vectors (Diaphorina citri in Asia and America). The uncultivable characteristic of CLas represents a major obstacle towards the knowledge on the molecular mechanisms underlying HLB. Comparative genomics of CLas, including other Candidatus Liberibacter spp., has allowed the prediction of the putative effector proteins, potentially involved in its pathogenicity mechanisms. In order to pro- vide a functional basis for this hypothesis, eight of these sequences were cloned and expressed fused to the green fluorescent protein (GFP) under the control of 35S promoter into the pMDC83 binary vector. Agrobacterium-mediated transient expressions were performed in citrus and Nicoti- ana benthamiana leaves. Bacterial protein expressions were monitored over a 10-day period by fluorescence and confo- cal laser scanning microscopy. All tested genes shown expres- sion in plant cells and two of them revealed different subcel- lular distribution patterns respect to the control, expressing only GFP. The role of these proteins is being analyzed.