This report describes part of the signaling pathway and some of the molecules involved in the auxin-induced adventitious root formation in @entity9688 ( @entity9688 ). Previous results showed that @entity842 (NO) mediates the auxin response during adventitious root formation (Pagnussat et al., 2002). To determine the order of action of @entity9634 ( @entity6207 ) and NO within the signal transduction pathway and to elucidate the target molecules that are downstream of NO action, @entity9688 hypocotyl cuttings were submitted to a pretreatment leading to endogenous auxin depletion. The auxin depletion treatment provoked a 3-fold reduction of the root number in comparison to the nondepleted explants. The NO-donor @entity1854 was able to promote adventitious rooting in auxin-depleted explants, whereas the specific NO scavenger @entity6706 prevented the effect of @entity1854 . The endogenous NO level was monitored in both control and auxin-depleted explants using a NO-specific fluorescent probe. The NO level was 3.5-fold higher in control (nondepleted) explants than in auxin-depleted ones. The exogenous application of @entity6207 restored the NO concentration to the level found in nondepleted explants. Because NO activates the enzyme guanylate cyclase (GC), we analyzed the involvement of the messenger @entity6708 in the adventitious root development mediated by @entity6207 and NO. The GC inhibitor @entity14642 reduced root development induced by @entity6207 and NO, whereas the cell-permeable @entity6708 derivative @entity11255 reversed this effect. The endogenous level of @entity6708 is regulated by both the synthesis via GC and its degradation by the phosphodiesterase activity. When assayed, the phosphodiesterase inhibitor @entity7855 was able to induce adventitious rooting in both nondepleted and auxin-depleted explants. Results indicate that NO operates downstream of @entity6207 promoting adventitious root development through the GC-catalyzed synthesis of @entity6708 .

XXXX and cyclic GMP are messengers in the @entity9634 -induced adventitious rooting process.

@entity6708 :: ('CHEBI:16356', 'Chemical') :: ['cGMP'] @entity6207 :: ('CHEBI:16411', 'Chemical') :: ['IAA'] @entity11255 :: ('CHEBI:64108', 'Chemical') :: ['8-Br-cGMP'] @entity6706 :: ('MESH:C079393', 'Chemical') :: ['cPTIO'] @entity1854 :: ('MESH:D009599', 'Chemical') :: ['sodium nitroprusside'] @entity9688 :: ('3659', 'Species') :: ['cucumber', 'Cucumis sativus'] @entity7855 :: ('MESH:C101426', 'Chemical') :: ['sildenafil citrate'] @entity842 :: ('MESH:D009569', 'Chemical') :: ['nitric oxide'] @entity14642 :: ('MESH:C041715', 'Chemical') :: ['LY83583'] @entity9634 :: ('MESH:C030737', 'Chemical') :: ['indole acetic acid']
@entity842 :: (MESH:D009569,Chemical) :: ['Nitric oxide']
