[Simultaneous knockout of ATG8h and ATG8i enhances disease resistance in Arabidopsis].

Autophagy plays a crucial role in plant immunity. However, the functions of Arabidopsis thaliana ATG8h and ATG8i in immune responses remain not fully understood. To investigate their roles and underlying molecular mechanisms in resistance to biotrophic bacteria, we performed disease resistance assay by inoculating the atg8h/atg8i double mutant we previously generated with the biotrophic bacterial pathogen Pseudomonas syringae pv. Tomato DC3000 (Pst DC3000). The results showed that the atg8h/atg8i double mutant exhibited enhanced resistance to Pst DC3000. Consistent with the enhanced resistance, the reactive oxygen species accumulation and the callose deposition induced by G. cichoracearum infection were significantly higher in the atg8h/atg8i double mutant lines than in the wildtype Col-0 plants. However, the enhanced disease resistance was independent of the activation of the MAPK pathway. Taken together, our results revealed that the ATG8h/ATG8i-parcitipated autophagy pathway plays a negative role in plant resistance against biotrophic pathogens. This study laid a foundation for enhancing broad-spectrum resistance in plants through manipulating the expression of ATG8h and ATG8i.