title: Metabolic regulation of the shoot apical meristem  by the TOR kinase in Arabidopsis thaliana
creator: Janocha, Denis
subject: ddc-500
subject: 500 Natural sciences and mathematics
subject: ddc-570
subject: 570 Life sciences
subject: ddc-580
subject: 580 Botanical sciences
description: Plants dynamically adjust their development and growth pattern to maximize their chances to reproduce even under challenging conditions. The cellular basis for this remarkable phenotypic plasticity are stem cell populations that are maintained throughout the whole life of a plant. Intricate sensing and signaling mechanisms are required to instruct stem cell behavior according to current needs. Consequently, light- and nutrient signals are integrated and modulate the core molecular circuits underlying regulation of the shoot apical meristem (SAM). We know that expression of the stem cell master regulator WUSCHEL (WUS) is modulated by photoreceptor mediated light signaling pathways together with sugar and nitrate. Activity of the evolutionary conserved TOR kinase is required to integrate and relay these signals, but we do not understand how TOR activity is conveyed to modulate WUS expression.  In this work, I identified CK signaling in an RNAseq approach as the major downstream effector of TOR activity controlling WUS expression and shoot development. I demonstrate that TOR activity stabilizes trans-Zeatin which is known to be one of the major determinants influencing shoot growth and meristem maintenance. Mechanistically, this is achieved by TOR dependent translational repression of CKX catabolic enzymes, allowing plants to swiftly adjust their growth factor milieu in response to dynamic environments. This study is the first example for TOR mediated translational repression of a catabolic enzyme and thus provides a mechanistic framework integrating the contributions of central metabolism and core developmental regulators towards stemness.
date: 2023
type: Dissertation
type: info:eu-repo/semantics/doctoralThesis
type: NonPeerReviewed
format: application/pdf
identifier: https://archiv.ub.uni-heidelberg.de/volltextserverhttps://archiv.ub.uni-heidelberg.de/volltextserver/31620/1/Dissertation_DenisJanocha.pdf
identifier: DOI:10.11588/heidok.00031620
identifier: urn:nbn:de:bsz:16-heidok-316209
identifier:   Janocha, Denis  (2023) Metabolic regulation of the shoot apical meristem by the TOR kinase in Arabidopsis thaliana.  [Dissertation]     
relation: https://archiv.ub.uni-heidelberg.de/volltextserver/31620/
rights: info:eu-repo/semantics/openAccess
rights: http://archiv.ub.uni-heidelberg.de/volltextserver/help/license_urhg.html
language: eng