Pseudomonas syringae pv. actinidiae Type III Effectors Localized at Multiple Cellular Compartments Activate or Suppress Innate Immune Responses in Nicotiana benthamiana

Bacterial phytopathogen type III secreted (T3S) effectors have been strongly implicated in altering the interaction of pathogens with host plants. Therefore, it is useful to characterize the whole effector repertoire of a pathogen to understand the interplay of effectors in plants. pv. is a causal agent of kiwifruit canker disease. In this study, we generated an -mediated transient expression library of YFP-tagged T3S effectors from two strains of , -NZ V13 and -NZ LV5, in order to gain insight into their mode of action in and . Determining the subcellular localization of effectors gives an indication of the possible host targets of effectors. A confocal microscopy assay detecting YFP-tagged effectors revealed that the nucleus, cytoplasm and cell periphery are major targets of effectors. -mediated transient expression of multiple effectors induced HR-like cell death (HCD) in spp., suggesting that multiple effectors may be recognized by spp.. Virus-induced gene silencing (VIGS) of several known plant immune regulators, , , or specified the requirement of SGT1 in HCD induced by several effectors in . In addition, the suppression activity of effectors on HCD-inducing proteins and PTI was assessed. effectors showed differential suppression activities on each HCD inducer or PTI. Taken together, our effector repertoire analysis highlights the great diversity of T3S effector functions .