Abstract
Cuscuta species (dodders) are common agriculturally destructive parasitic angiosperms. However, some tomato cultivars exhibit resistance to dodders. The stem cortex in these lines responds with local lignification upon C. campestris attachment, preventing parasite penetration into host. We compared gene expression patterns under C. campestris infestation in resistant and susceptible cultivars and identified LIF1 (Lignin Induction Factor 1, an AP2-like transcription factor), MYB55, and CuRLR1 (Cuscuta Receptor for Lignin-based Resistance 1, a CC-NBS-LRR) as key factors conferring host resistance. Transient overexpression results suggest that MYB55 and LIF1 directly regulate cortical lignification. Moreover, CuRLR1 functions as a receptor for receiving C. campestris signals to regulate lignification-based resistance. We also identified WRKY16 as a negative regulator of LIF1 function. These results will aid in developing parasitic plant-resistant crops.
One Sentence Summary Lignin-based resistance to Cuscuta in tomato.
