Gonzalez, Juan H.Taylor, Joseph S.Reed, Kelsey M.Wright, R. ClayBargmann, Bastiaan O. R.2021-11-112021-11-112021-10-23Gonzalez, J.H.; Taylor, J.S.; Reed, K.M.; Wright, R.C.; Bargmann, B.O.R. Temporal Control of Morphogenic Factor Expression Determines Efficacy in Enhancing Regeneration. Plants 2021, 10, 2271.http://hdl.handle.net/10919/106600Background: Regeneration of fertile plants from tissue culture is a critical bottleneck in the application of new plant breeding technologies. Ectopic overexpression of morphogenic factors is a promising workaround for this hurdle. Methods: Conditional overexpression of <i>WUS</i> and <i>ARF5</i>Δ was used to study the effect of timing the overexpression of these morphogenic factors during shoot regeneration from root explants in Arabidopsis. In addition, their effect on auxin-signaling activation was examined by visualization and cytometric quantification of the DR5:GFP auxin-signaling reporter in roots and protoplasts, respectively. Results: The induced expression of both <i>WUS</i> and <i>ARF5</i>Δ led to an activation of auxin signaling in roots. Activation of auxin signaling by <i>WUS</i> and <i>ARF5</i>Δ was further quantified by transient transformation of protoplasts. Ectopic overexpression of both <i>WUS</i> and <i>ARF5</i>Δ enhanced regeneration efficiency, but only during the shoot-induction stage of regeneration and not during the callus-induction stage. Conclusions: The overexpression of <i>WUS</i> and <i>ARF5</i>Δ both lead to activation of auxin signaling. Expression during the shoot-induction stage is critical for the enhancement of shoot regeneration by <i>WUS</i> and <i>ARF5</i>Δ.application/pdfenCreative Commons Attribution 4.0 Internationalplant regenerationmorphogenic factorsconditional expressionauxin signalingArticle - Refereed2021-11-11https://doi.org/10.3390/plants10112271