Tomato ATG1 is implicated in the development of cell death associated with bacterial speck disease and hypersensitive response

POMBO M.; BEKIER F.; ROSLI H.

Córdoba

Congreso; XXXII Reunión Argentina y XVI Congreso Latinoamericano de Fisiología Vegetal; 2018

Sociedad Argentina de Fisiología Vegetal

Pseudomonas syringae pv. tomato (Pst) is the causal agent of the tomato speck disease. In resistant tomatoes, Pto protein recognizes two bacterial effectors (AvrPto and AvrPtoB) and jointly with Prf activativate effector-triggered immunity (ETI), which includes the hypersensitive response. Using previously generated RNA-seq data, we selected a group of genes whose expression was induced specifically when ETI is activated. Phylogenetic analysis allowed us the identification of Nicotiana benthamiana closest genes. Using this information we designed constructs to perform virus induced gene silencing (VIGS) in this model plant. We identified a protein kinase closest to the Arabidopsis thaliana autophagy-related protein 1 (ATG1), whose silencing shows a delay in the development of programmed cell death (PCD) after the co-expression of Pto and AvrPto proteins in plant. To confirm this result, we performed disease assays in N. benthamiana-35S::pto plants using Pseudomonas syringae pv. tabaci (Ps tab) expressing AvrPto or the empty vector (EV). We did not observe differences in disease symptoms using Ps tab-AvrPto. However, silencing of ATG1 delayed the disease development due to Ps tab-EV challenge. Therefore, we hypothesize that this protein could be involved in the development of symptoms associated with PCD and also with pathogen disease.