Discovery of a Broad-Spectrum Fluorogenic Agonist for Strigolactone Receptors through a Computational Approach

Area of Science:

• Plant Biology
• Biochemistry
• Chemical Biology

Background:

• Strigolactones (SLs) are crucial plant hormones regulating growth and development.
• SL receptors, likely α/β-hydrolases, are key targets for understanding SL signaling.
• Developing effective assays for SL receptor activity is vital for SL-related research and applications.

Purpose of the Study:

• To develop a novel, sensitive assay for measuring strigolactone (SL) receptor activity.
• To discover and characterize a new fluorescent probe for SL receptors.
• To explore the potential of SL receptor modulators in controlling parasitic weeds.

Main Methods:

• Pharmacophore-linked probe virtual screening (PPVS) was employed to identify potential probes.
• A novel "off-on" fluorescent probe, Xilatone Red (XLR), was synthesized and characterized.
• The probe's performance was evaluated against SL receptors, including ShD14, and its biological activity was tested on parasitic weeds and plant mutants.

Main Results:

• Xilatone Red (XLR) demonstrated broad-spectrum and high sensitivity towards SL receptors, surpassing commercial probes like Yoshimulactone Green (YLG).
• XLR exhibited fluorogenic and colorimetric responses upon hydrolysis by SL receptors.
• XLR effectively induced parasitic weed germination and rescued plant developmental defects at micromolar concentrations.

Conclusions:

• Xilatone Red (XLR) is a potent and sensitive tool for studying strigolactone (SL) receptor activity.
• The developed probe and screening method can accelerate the discovery of SL agonists/antagonists.
• This research offers promising avenues for developing novel strategies to combat parasitic weeds.