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ARS Home » Northeast Area » Washington, D.C. » National Arboretum » Floral and Nursery Plants Research » Research » Publications at this Location » Publication #398297

Research Project: Evaluation and Genetic Improvement of Woody Ornamental Landscape Plants

Location: Floral and Nursery Plants Research

Title: Characterization of host-effector transcription dynamics during pathogen infection in engineered late blight resistant potato

item Duan, Hui
item MORESCO, PAUL - Jr Simplot Company
item CHAMPOURET, NICOLAS - Jr Simplot Company

Submitted to: Transgenic Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/20/2023
Publication Date: 3/4/2023
Citation: Duan, H., Moresco, P., Champouret, N. 2023. Characterization of host-effector transcription dynamics during pathogen infection in engineered late blight resistant potato. Transgenic Research.

Interpretive Summary: Late blight (LB), caused by the fungal pathogen Phytophthora infestans, is one of the worst potato diseases historically and currently. LB-resistant potatoes have been produced using biotechnology by introducing the resistant R gene from wild potato species into commercially important potato varieties. The resulting biotech potato showed significant resistance to late blight infection, but it was not clear how the introduced R gene interacted with the pathogen, especially at early stages of infection. In addition, the quantity of the R-gene products present in these potatoes after infection with the fungal pathogen was unknown. When working for a previous employer, an ARS scientist and collaborators examined the expression of the R gene introduced in biotech potatoes and the effect on the gene of the fungal pathogen after plants were challenged with different pathogen isolates. The results indicated that very low-level expression of introduced R gene is sufficient to confer resistance, and the gene products quickly disappeared after the pathogen was eliminated by this defense response.

Technical Abstract: Phytophthora infestans, the etiologic agent of late blight, is a threat to potato production in areas with high humidity during the growing season. The oomycete pathogen is hemi-biotrophic, it establishes infection on living plant cells and then spreads, kills, and feeds off the necrotized plant tissue material. The interaction between host and pathogen is complex with dynamic pathogen RXLR effectors and potato NB-LRR resistance proteins actively competing for dominance and survival. Late blight protection was brought to several cultivars of potato through insertion of the wild potato (Solanum venturii) NB-LRR resistance gene Rpi-vnt1.1. We have established that the late blight protection trait, mediated by Rpi-vnt1.1, is effective despite low expression of RNA and protein (i.e. <500 ppb). The RNA expression dynamics of Rpi-vnt1.1 and the cognate pathogen RXLR effector, Avr-vnt1, were evaluated following spray inoculation with up to five different contemporary late blight isolates from North America and South America. Following inoculations, RXLR effector transcript profiles provided insight into interaction compatibility in relation to markers of the late blight hemi-biotrophic lifecycle.