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

The artificially synthesized strigolactone (SL) analogue GR24 is currently the most widely used reference compound in studying the biological functions of SLs. To elucidate the structure-activity relationship and find more promising derivatives with unique molecular profiles, we design and synthesized three series of novel GR24 derivatives and explored their activities in hypocotyl and root development of . Among the 50 synthesized compounds, , , and were found to have high activities comparable to GR24 for hypocotyl and/or primary root elongation inhibition in . Some new analogues have been discovered to exhibit unique activities: (1) , , and are specific inhibitors in primary root elongation; (2) , , and exhibit a high promotion effect on primary root elongation; and (3) possesses the most unique profiles completely opposite to GR24 that promotes both hypocotyl elongation and primary root development. Moreover, we revealed that the AtD14 receptor does not affect the inhibitory effect of SL analogues in root development. The ligand-receptor interactions for the most representative analogues and were deciphered with a long time scale molecular dynamics simulation study, which provides the molecular basis of their distinct functions, and may help scientists design novel phytohormones.