Summary Arabidopsis RESISTANCE TO POWDERY MILDEW 8.2 (RPW8.2) is specifically induced by the powdery mildew (PM) fungus (Golovinomyces cichoracearum) in the infected epidermal cells to activate immunity. However, the mechanism of RPW8.2‐induction is not well understood. Here, we identify a G. cichoracearum effector that interacts with RPW8.2, named Gc‐RPW8.2 interacting protein 1 (GcR8IP1), by a yeast two‐hybrid screen of an Arabidopsis cDNA library. GcR8IP1 is physically associated with RPW8.2 with its REALLY INTERESTING NEW GENE finger domain that is essential and sufficient for the association. GcR8IP1 was secreted and translocated into the nucleus of host cell infected with PM. Association of GcR8IP1 with RPW8.2 led to an increase in RPW8.2 in the nucleus. In turn, the nucleus‐localized RPW8.2 promoted the activity of the RPW8.2 promoter, resulting in transcriptional self‐amplification of RPW8.2 to boost immunity at infection sites. Additionally, ectopic expression or host‐induced gene silencing of GcR8IP1 supported its role as a virulence factor in PM. Altogether, our results reveal a mechanism of RPW8.2‐dependent defense strengthening via altered partitioning of RPW8.2 and transcriptional self‐amplification triggered by a PM fungal effector, which exemplifies an atypical form of effector‐triggered immunity.

Summary The rubber tree (Hevea brasiliensis) is grown in tropical regions and is the major source of natural rubber. Using traditional breeding approaches, the latex yield has increased by sixfold in the last century. However, the underlying genetic basis of rubber yield improvement is largely unknown. Here, we present a high‐quality, chromosome‐level genome sequence of the wild rubber tree, the first report on selection signatures and a genome‐wide association study (GWAS) of its yield traits. Population genomic analysis revealed a moderate population divergence between the Wickham clones and wild accessions. Interestingly, it is suggestive that H. brasiliensis and six relatives of the Hevea genus might belong to the same species. The selective sweep analysis found 361 obvious signatures in the domesticated clones associated with 245 genes. In a 15‐year field trial, GWAS identified 155 marker–trait associations with latex yield, in which 326 candidate genes were found. Notably, six genes related to sugar transport and metabolism, and four genes related to ethylene biosynthesis and signalling are associated with latex yield. The homozygote frequencies of the causal nonsynonymous SNPs have been greatly increased under selection, which may have contributed to the fast latex yield improvement during the short domestication history. Our study provides insights into the genetic basis of the latex yield trait and has implications for genomic‐assisted breeding by offering valuable resources in this new domesticated crop.