Multiple immunity-related genes control susceptibility ofArabidopsis thalianato the parasitic weedPhelipanche aegyptiaca

Abstract

Parasitic weeds represent a major threat to agricultural production across the world. Little is known about which host genetic pathways determine compatibility for any host–parasitic plant interaction. We developed a quantitative assay to characterize the growth of the parasitic weedPhelipanche aegyptiacaon 46 mutant lines of the host plantArabidopsis thalianato identify host genes that are essential for susceptibility to the parasite.A. thalianahost plants with mutations in genes involved in jasmonic acid biosynthesis/signaling or the negative regulation of plant immunity were less susceptible toP. aegyptiacaparasitization. In contrast,A. thalianaplants with a mutant allele of the putative immunity hub genePfd6were more susceptible to parasitization. Additionally, quantitative PCR revealed thatP. aegyptiacaparasitization leads to transcriptional reprograming of several hormone signaling pathways. While most testedA. thalianalines were fully susceptible toP. aegyptiacaparasitization, this work revealed several host genes essential for full susceptibility or resistance to parasitism. Altering these pathways may be a viable approach for limiting host plant susceptibility to parasitism.