P-067 - Potato NLR Rpi-vnt1.1 confers resistance at plasma membrane via dynamin-dependent manner

In plants, the hypersensitive response provoked by the activation of nucleotide-binding leucine-rich repeat (NLR) plays a major role in inducing a robust immune response via the recognition of cognate avirulence (AVR) effector. Although NLR genes have been cloned from various wild potato species, little is known about how potato NLRs perceive the AVR effectors and trigger an immune response, especially in the case of Rpi-vnt1.1. In this study, we discovered the molecular mechanism of Rpi-vnt1.1-mediated immune response by using Phytophthora infestans effectors belonging to the AVRvnt1 family. By comparing the effector domain differences of AVRvnt1 family effectors, we found that AVRvnt1-specific Tyr-Ile-Tyr residues at the C-terminus are indispensable for Rpi-vnt1.1 activation. In addition, we found that the N-terminus of AVRvnt1 is required for membrane bounding and Rpi-vnt1.1 activation. Moreover, we discovered that AVRvnt1 and Rpi-vnt1.1 are tightly associated with heat shock protein 70 and dynamin is also involved in this complex, specifically upon Rpi-vnt1.1 activation. Finally, we confirmed that activated Rpi-vnt1.1 localizes at the plasma membrane with AVRvnt1 expression. These results emphasize that the interaction between AVRvnt1 and new host target at the plasma membrane plays a key role in activating Rpi-vnt1.1.