P-027 - Dissecting resistance to Phytophthora capsici in pepper through an effectoromics approach

Wednesday, July 16, 2025

13:30 - 15:15

Location: Confex Hall 3

Crop resistance genetics and genomics

Presenting Author(s)

GM

Guillermo Merino Martin

Laboratory of Plant Breeding, Wageningen University and Research
Wageningen, Gelderland, Netherlands

Author(s)

SG

Suzan H.E.J. Gabriëls

Laboratory of Plant Breeding, Wageningen University and Research
Wageningen, Gelderland, Netherlands
DE

Danny Esselink

Laboratory of Plant Breeding, Wageningen University and Research
Wageningen, Gelderland, Netherlands
DW

Doret Wouters

Plant Breeding, Wageningen University and Research
Wageningen, Gelderland, Netherlands
YB

Yuling Bai

Professor
Wageningen University and Research/PBR
Wageningen, Gelderland, Netherlands
VV

Vivianne Vleeshouwers

Wageningen University & Research
Wageningen, Gelderland, Netherlands

Phytophthora capsici poses a severe threat to global pepper (Capsicum spp.) production, with resistance largely relying on the C. annuum accession CM334. To diversify the genetic sources of resistance, we screened 500 diverse Capsicum accessions, spanning multiple species and geographic origins, for resistance to a highly virulent P. capsici isolate. We identified 10 novel resistance sources that are genetically distinct from CM334. Testing these accessions with 10 genetically diverse P. capsici isolates revealed a spectrum of resistance responses, including both broad-spectrum and isolate-specific resistance. To dissect the molecular basis of these resistance patterns, we are employing an effectoromics approach. A time-course RNA-seq analysis of P. capsici infection on a susceptible pepper identified 150 effectors upregulated during early infection. Subsequently, all 150 effectors were cloned into expression vectors for functional analysis using PVX agroinfection on the 10 identified resistant sources plus susceptible controls. Pepper accessions responding with an HR indicate presence of host targets likely correlated to the immune responses triggered in resistant accessions. Our findings enhance the understanding of P. capsici-Capsicum interactions and provide novel genetic resources for breeding programs aimed at developing durable and broad-spectrum resistance to multiple P.capsici isolates.