A marine bacterium elicits the type III secretion-dependent nonhost hypersensitive response in a land plant

Abstract

ABSTRACTActive plant immune response involving programmed cell death called the hypersensitive response (HR) is elicited by microbial effectors delivered through the type III secretion system (T3SS). The marine bacteriumHahella chejuensiscontains two T3SSs that are similar to those of animal pathogens, but elicited HR-like cell death in the land plantNicotiana benthamiana, which was mediated by SGT1 and suppressed by AvrPto1. Thus, the land plant is capable of inducing the cell death in response to type III-secreted effectors of the marine bacterium it never have encountered, suggesting that plants may have evolved to cope with a potential threat posed by alien effectors.One-sentence summaryA marine bacteriumHahella chejuensisharboring functional type III secretion systems induced nonhost hypersensitive response in a land plantNicotiana benthamiana, which was mediated by SGT1 and suppressed by AvrPto1.