The transcription factor ESR2/DRNL/BOL differentially regulates de novo organogenesis, regeneration, and lateral root development in Arabidopsis thaliana

The transcription factor ESR2/DRNL/BOL plays a critical role in regulating organogenesis, regeneration, and lateral root development in the model plant Arabidopsis thaliana. This factor, which is expressed in aerial organ founder cells, promotes the formation of shoots and aerial-like tissues while enhancing callus proliferation, especially in the presence of high cytokinin levels.

However, ESR2 exhibits antagonistic effects on root development, suppressing or delaying multiple de novo root formation programs such as adventitious, basal, and regenerated roots. Under normal conditions, ESR2's loss enhances root initiation and growth.

The expression of ESR2 is found at de novo formed basal and adventitious root primordia and emerging root apical meristems, suggesting that it confers regenerative competence while restricting the progression of root development. Furthermore, ESR2 is expressed in the quiescent centers of lateral roots in intact plants, and its loss negatively impacts lateral root initiation, highlighting its role in lateral root formation.

These findings collectively identify ESR2 as a shared molecular regulator that governs early organogenesis in both intact plants and plant explants, establishing an aerial organ fate bias while maintaining the capacity for, yet limiting, the progression of, de novo root development in explants.