Sucrose Enhances Adventitious Root Formation in Nitraria tangutorum Under Drought Stress via Hormonal Homeostasis and Hydrogen Peroxide Signaling

ABSTRACT The robust adventitious root (AR) system of Nitraria tangutorum facilitates its adaptation to drought stress; however, the molecular mechanisms governing AR formation during drought remain unclear. In this study, we demonstrated that a sucrose (40 g L −1 ) treatment of N. tangutorum explants for 48 h significantly increased the rate of AR development from 36% in the untreated control group to 100%. Transcriptome analysis revealed sucrose exerts a significant influence on H 2 O 2 homeostasis and hormone signal transduction pathways. Sucrose treatment promoted IAA biosynthesis through the upregulation of TSA , TSB , and YUC genes and suppressed gibberellin (GA) and cytokinin biosynthesis by downregulating CPS , GA3ox , GA20ox , and LOG . Moreover, sucrose induced abscisic acid (ABA) and salicylic acid (SA) accumulation while reducing JA‐Ile, and activated H 2 O 2 signaling through the upregulation of RBOH . Exogenous H 2 O 2 (1–8 mM) mimicked the effects of sucrose; however, this effect was abolished by the auxin transport inhibitor TIBA, indicating that the effects of H 2 O 2 depend on auxin signaling. These results reflect that sucrose acts as an energy substrate as well as a signaling molecule to coordinate hormonal interactions and redox signaling during drought‐adaptive AR formation.