Differences in intensity and specificity of hypersensitive response induction in Nicotiana spp. by INF1, INF2A, and INF2B of Phytophthora infestans.

摘要: Elicitins form a family of structurally related proteins that induce the hypersensitive response (HR) in plants, particularly Nicotiana spp. The elicitin is composed several classes. Most species plant-pathogenic oomycete genus Phytophthora produce well-characterized 10-kDa canonical elicitins (class I), such as INF1 potato and tomato pathogen infestans. Two genes, inf2A inf2B, encoding distinct class III) elicitinlike proteins, also occur P. Unlike secreted I elicitins, III are thought to be cell-surface-anchored polypeptides. Molecular characterization inf2 genes indicated they widespread small gene family. In addition, Southern blot Northern hybridizations using gene-specific probes showed inf2B transcripts can detected 17 different infestans isolates. Functional expression plant cells domain inf1 was conducted binary Potato virus X (PVX) vector (agroinfection) Agrobacterium tumefaciens transient transformation assays (agroinfiltration), resulted HR-like necrotic symptoms induction defense tobacco. However, comparative analyses elicitor activity INF1, INF2A, INF2B revealed significant differences intensity, specificity, consistency HR induction. Whereas induced benthamiana, INF2A weak no on this plant. Nonetheless, similar by N. benthamiana required ubiquitin ligase-associated protein SGT1. Overall, these results suggest variation resistance shadowed INF elicitins. ability tobacco, but not respond could explain observed for two species.