The circadian clock rephases during lateral root organ initiation in Arabidopsis thaliana

Abstract

El reloj circadiano endógeno permite a los organismos adaptar su crecimiento y desarrollo a los cambios ambientales. Aquí describimos cómo el reloj circadiano es empleado para coordinar las respuestas a la señal clave de las auxinas durante la aparición de la raíz lateral (LR). En la planta modelo Arabidopsis thaliana, LRs proceden de un grupo de células madre de raíz profunda, que requiere que los nuevos órganos emerjan a través de tejidos subyacentes de la raíz. Nos informan que el desarrollo del reloj circadiano reprogramara a LR. El metabolito y los perfiles de transcripción revelaron que el reloj circadiano controla los niveles de auxina, incluyendo genes relacionados con la respuesta de auxinas AIA represor14 y la auxina oxidasa AtDAO2. Las plantas carecen de componentes de reloj del núcleo para indicar o exhibir la aparición de defectos en LR. Concluimos que los actos del reloj circadiano conducen a la señalización de la auxina durante el desarrollo de la LR para facilitar el surgimiento de órganos. ; The endogenous circadian clock enables organisms to adapt their growth and development to environmental changes. Here we describe how the circadian clock is employed to coordinate responses to the key signal auxin during lateral root (LR) emergence. In the model plant, Arabidopsis thaliana, LRs originate from a group of stem cells deep within the root, necessitating that new organs emerge through overlying root tissues. We report that the circadian clock is rephased during LR development. Metabolite and transcript profiling revealed that the circadian clock controls the levels of auxin and auxin-related genes including the auxin response repressor IAA14 and auxin oxidase AtDAO2. Plants lacking or overexpressing core clock components exhibit LR emergence defects. We conclude that the circadian clock acts to gate auxin signalling during LR development to facilitate organ emergence. ; Acknowledge Engineering and Physical Sciences Research Council (EPSRC)funding to the Centre for Plant Integrative Biology (CPIB) BB/D019613/1; U.V, K.S. and M.J.B. acknowledge funding from BBSRC grant BB/H020314/1; K.K., M.H.W. and K.S. acknowledge the support of the European Research Community Advanced Investigator Funding to M.J.B (FUTUREROOTS); D.M.W. and M.J.B. acknowledge BBSRC funding from grant BB/J009717/1 and U.V. and D.M.W. from the BBSRC Professorial Research Fellowship funding to M.J.B. grant BB/G023972/1; JSPS Fellowship to T.G., H.F. and M.J.B.; BBSRC funding for F.C.R and A.A.R.W. from grant BB/D017904/1; and Royal Society-Wolfson Merit Award to M.J.B. Work at the University of Liverpool by P.D.G and A.J.H was supported by the BBSRC/EPSRC-funded ROBuST SABR project BB/F005318/1 and BBSRC grant BB/K018078/1. M.L. and L.L. were supported by the Région Languedoc Roussillon ('Chercheur d'Avenir' grant to LL) and the Agropolis Fondation Rhizopolis project. B.P. acknowledges the support of an Intra-European Fellowship for Career Development under the seventh framework of the European Commission (IEF-2008-220506), an EMBO Long-Term Fellowship, a European Reintegration Grant under the seventh framework of the European Commission (ERG-2010-276662). K.L. acknowledges the Swedish Governmental Agency for Innovation Systems (VINNOVA)and the Swedish Research Council (VR). W.A.P. and A.S.M. acknowledge funding from the Maryland Agricultural Experiment Station and DOE Physical Biosciences Basic Energy Sciences (DE-FG02-13ER16405). ; peerReviewed