Dodder (Cuscuta campestris) is a plant that parasitizes other plants by forming penetrating haustoria through which they tap into the host’s vascular tissues and extract nutrients. Most tomatoes are susceptible, but a few varieties are resistant. Jhu and Farhi et al. examined these resistant varieties to determine the genetic basis for resistance, using comparative transcriptomics and gain-of-function studies in susceptible lines. They found that both resistant and susceptible cultivars exhibited wound responses and localized cell death, but only the resistant plants showed enhanced stem lignification which prevented haustorial penetration. The authors also identified two transcription factors involved in the lignification response which, when introduced into susceptible cultivars, leads to enhanced lignification and resistance to dodder. (Summary by Mary Williams) bioRxiv 10.1101/706861.