Induced defence by a root hemiparasite increases host plant resistance against future infection
Year: 2026
Type: article
Abstract: European grassland plants are frequently attacked by root hemiparasites. However, little is known about host defence responses to parasitism. We investigated whether prior parasitization by a root hemiparasite makes hosts more susceptible to parasitism or, on the contrary, stimulates host defence against a future attack by hemiparasites. We grew three host species (Lolium perenne, Trifolium repens and Sanguisorba minor) in phase 1 for 3 months with the hemiparasite Rhinanthus alectorolophus, removed the parasite and grew the same host individuals in phase 2 with the hemiparasites R. alectorolophus or Melampyrum arvense. Previous infection by a parasite reduced the survival of the seedlings of Rhinanthus and Melampyrum with all host species but increased the biomass of the surviving parasites. A previous infection reduced the biomass of the hosts in most treatment combinations, but variation in initial host biomass at the start of phase 2 only partly explained this effect. Some of these interactions were specific to particular parasite-host species combinations. The results indicate that infection by root hemiparasites induces in the hosts defence mechanisms against future infection by the parasites (increased pre-attachment resistance), but parasite individuals that overcome this defence may then also be particularly good at exploiting the hosts (no increased post-attachment resistance). Thus, infection by root hemiparasites may activate host defence pathways that can influence future interactions with herbivores and pathogens and thus community dynamics.
Source: Plant Biology
DOI: 10.1111/plb.70187
Authors: S. C. Wanke, D. Matthies
Institution: Philipps University of Marburg
Language: English
Subfield: Plant Science
Domain: Life Sciences
SDG: Life on land
Open Access status: hybrid
Estimated APC paid: $3,400
OpenAlex ID: W7127039368