BES1 and BZR1 redundantly promote phloem and xylem differentiation ($) (Plant Cell Physiol.)

In vascular development, procambial or cambial cells differentiate into xylem and phloem. In this research article, by using VISUAL (Vascular cell Induction culture System Using Arabidopsis Leaves) system, Saito et al. identified BES1 (BRI1 EMS SUPPRESSOR 1) as one of the components required for xylem differentiation. They found that BES1 also positively regulates phloem differentiation and acts downstream of GSK3 (Glycogen Synthase Kinase 3). In addition, the close homolog of BES1, BZR1, works redundantly in the same developmental pathway. This study shows the involvement of brassinosteroid-signaling transcription factors (BES1, BZR1) as regulators for xylem and phloem cell differentiation from vascular stem cells. (Summary by Arif Ashraf)  Plant Cell Physiol. 10.1093/pcp/pcy012