Table 2. Working Definitions for Plant–Virus Interactions and Immune Responses.

Term	Working Definition
Viral effectors	Virus-encoded proteins that when present in host cells interfere with host defense signaling components to promote virulence
Viral ETI	A type of host immune response triggered by R proteins that recognize, directly or indirectly, virus-encoded effectors or their activities within the host cells
Viral PTI	A type of basal host immune response triggered upon recognition of conserved viral molecular features by specific membrane-bound receptor-like proteins