Bewitching the host: Striga disrupts host stomatal ABA signaling by impairing the tryptophan lock

Parasitic plants of the Orobanchaceae family, particularly Striga hermonthica, rank among the world's most devastating agricultural weeds (Jamil et al., 2021). They inflict massive yield losses on staple cereal crops across Africa, including sorghum, millet, and rice, as well as globally on other essential crops such as maize, rapeseed, tomato, and legumes (Parker et al., 2009; Bouwmeester, 2018). These root parasites have evolved a specialized organ called the ‘haustorium’ that connects to the vascular system of the host to siphon water, minerals, and nutrients (Yang et al., 2015). A critical component of this strategy is maintaining a lower water potential (LWP) than the host to drive a bulk flow of xylem sap into the parasite (Smith and Stewart, 1990; Katagiri et al., 2025).