P-305 - The RPP1 gene cluster is highly diverse yet locally dispensable

Monday, July 14, 2025

13:30 - 15:15

Location: Confex Hall 3

Population Biology, Ecology & Genomics

Presenting Author(s)

ML

Miriam Lucke

Max Planck Institute for Biology
Tuebingen, Baden-Wurttemberg, Germany

Author(s)

HA

Haim Ashkenazy

Max Planck Institute for Biology Tuebingen
Tuebingen, Baden-Wurttemberg, Germany
LT

Luisa Teasdale

Max Planck Institute for Biology
Tübingen, Baden-Wurttemberg, Germany
IB

Ilja Bezrukov

Max Planck Institute for Biology
Tübingen, Baden-Wurttemberg, Germany
ZB

Zhigui Bao

Max Planck Institute for Biology
Tübingen, Baden-Wurttemberg, Germany
AM

Andrea Movilli

Max Planck Institute for Biology
Tübingen, Baden-Wurttemberg, Germany
RS

Rebecca Schwab

Max Planck Institute for Biology
Tübingen, Baden-Wurttemberg, Germany
DW

Detlef Weigel

Max Planck Institute for Biology
Tübingen, Baden-Wurttemberg, Germany

The arms race between hosts and pathogens can drive co-evolution of immune receptors and pathogen effectors. In Arabidopsis thaliana, certain alleles of the NLR-encoding RPP1 locus detect variants of the Hyaloperonospora arabidopsidis effector ATR1 by direct interaction. We annotated the RPP1 locus in 265 Arabidopsis thaliana accessions with high-quality genomes and found copy number to vary from 0 to 13. Only two of the studied accessions lacked the RPP1 locus entirely. We re-visited the original collection site of one of them and found that ~ 60% of the plants in the local population also lacked the RPP1 locus, indicating that, at least locally, the absence of RPP1 protein may not lead to a dramatic fitness loss. Interestingly, our genome-wide analyses identified individuals of two distinct haplotypes in the local population, and all individuals without RPP1 belonged to the same haplotype group, which also contained individuals with one or more RPP1 copies. Infections with local H.arabiopsidis isolates revealed that this mixed group was overall more resistant. This is consistent with our genetic analyses that located resistance-carrying loci to other chromosomes. Ongoing analyses aim to elucidate the functional differences between these two locally collected sub-populations and the role of RPP1 in pathogen resistance.