Strigolactone inhibits hydrogen peroxide and plasma membrane H⁺-ATPase activities to downregulate adventitious root formation in mung bean hypocotyls

Strigolactones regulate root development and are known to inhibit adventitious root formation. However, the hormonal targets of strigolactones during adventitious rooting are yet to be determined. As a signal molecule, H₂O₂ stimulates adventitious rooting. On the other hand, plasma membrane H⁺-ATPase is involved in several hormonal signals that are linked to root development. This study evaluated the influence of a synthetic strigolactone (rac-GR24), H₂O₂, and plasma membrane H⁺-ATPase on adventitious root formation in mung bean hypocotyls. We also determined if H₂O₂ and plasma membrane H⁺-ATPases are possible hormonal targets in strigolactone-mediated inhibition of adventitious rooting. The results confirm the inhibitory role of strigolactones and the enhancing influence of H₂O₂ on adventitious rooting while also suggesting that plasma membrane H⁺-ATPase activity is necessary and may be employed to regulate adventitious rooting. Also, rac-GR24 diminished endogenous H₂O₂ content by inhibiting NOX and SOD activities while also inhibiting plasma membrane H⁺-ATPase activity. Therefore, we conclude that interference with H₂O₂ signaling and plasma membrane H⁺-ATPase activity may serve as a potent hormonal mechanism that may be employed by strigolactones to downregulate adventitious rooting in mung bean hypocotyls.