Synthesis and Biological Profiling of Novel Strigolactone Derivatives for Arabidopsis Growth and Development

The artificially synthesized strigolactone (SL) analogueGR24 iscurrently the most widely used reference compound in studying thebiological functions of SLs. To elucidate the structure-activityrelationship and find more promising derivatives with unique molecularprofiles, we design and synthesized three series of novel GR24 derivativesand explored their activities in hypocotyl and root development of Arabidopsis. Among the 50 synthesized compounds, A11a, A12a, and A20d were foundto have high activities comparable to GR24 for hypocotyl and/or primaryroot elongation inhibition in Arabidopsis. Some new analogues have been discovered to exhibit unique activities:(1) A20c, A21e, and A21o arespecific inhibitors in primary root elongation; (2) A21c, A26c, and A27a exhibit a high promotioneffect on Arabidopsis primary rootelongation; and (3) A27e possesses the most unique profilescompletely opposite to GR24 that promotes both hypocotyl elongationand primary root development. Moreover, we revealed that the AtD14receptor does not affect the inhibitory effect of SL analogues in Arabidopsis root development. The ligand-receptorinteractions for the most representative analogues A11a and A27e were deciphered with a long time scale moleculardynamics simulation study, which provides the molecular basis of theirdistinct functions, and may help scientists design novel phytohormones.

Automated summary

The activities of three series of novel GR24 derivatives in hypocotyl and root development of Arabidopsis were explored. Among the synthesized compounds, A11a, A12a, and A20d showed high activities similar to GR24 in inhibiting hypocotyl and/or primary root elongation in Arabidopsis. Additionally, some new analogues exhibited unique activities.