TY - JOUR T1 - Vernalization alters sugar beet (<em>Beta vulgaris</em>) sink and source identities and reverses phloem translocation from taproots to shoots JF - bioRxiv DO - 10.1101/2020.01.28.922906 SP - 2020.01.28.922906 AU - Cristina Martins Rodrigues AU - Christina Müdsam AU - Isabel Keller AU - Wolfgang Zierer AU - Olaf Czarnecki AU - José María Corral AU - Frank Reinhardt AU - Petra Nieberl AU - Frederik Sommer AU - Michael Schroda AU - Timo Mühlhaus AU - Karsten Harms AU - Ulf-Ingo Flügge AU - Uwe Sonnewald AU - Wolfgang Koch AU - Frank Ludewig AU - H. Ekkehard Neuhaus AU - Benjamin Pommerrenig Y1 - 2020/01/01 UR - http://biorxiv.org/content/early/2020/01/28/2020.01.28.922906.abstract N2 - During vegetative growth, biennial sugar beets maintain a steep gradient between the shoot (source) and the sucrose-storing taproot (sink). To shift from vegetative to generative growth, they require a chilling phase, called vernalization. Here, we studied sugar beet sink-source dynamics upon cold temperature-induced vernalization and revealed a pre-flowering taproot sink to source reversal. This transition is induced by transcriptomic and functional reprogramming of sugar beet tissue, resulting in a reversal of flux direction in long distance transport system, the phloem. As a key process for this transition, vacuolar sucrose importers and exporters, BvTST2;1 and BvSUT4, are oppositely regulated, leading to re-mobilization of sugars from taproot storage vacuoles. Concomitant changes in the expression of floral regulator genes suggest that the now deciphered processes are a prerequisite for bolting. Our data may thus serve dissecting metabolic and developmental triggers for bolting, which are potential targets for genome editing or breeding approaches. ER -