Gibberellins Promote Seed Conditioning by Up-Regulating Strigolactone Receptors in the Parasitic Plant Striga hermonthica.

This article investigates the role of the plant hormone gibberellins (GAs) in the seed conditioning and germination of *Striga hermonthica*, a root parasitic plant that senses host-derived strigolactones (SLs) to initiate germination. The study demonstrates that GAs enhance the competence of dormant *Striga* seeds to respond to SLs by up-regulating the expression of major SL receptor genes (ShHTLs) during the conditioning period, a phase required for seeds to become responsive to germination cues. Chemical inhibition of GA biosynthesis during conditioning reduced SL receptor expression, delayed SL perception dynamics, and impaired germination, effects that were rescued by exogenous GA application. These findings suggest that, unlike in non-parasitic plants where GAs directly stimulate germination, in *Striga* GAs play an indirect but essential role by promoting seed conditioning and sensitivity to host signals, highlighting potential applications for managing *Striga* infestations in agriculture.