Development and carotenoid synthesis in dark-grown carrot taproots require PHYTOCHROME RAPIDLY REGULATED1
Arias, Daniela (Universidad de Chile. Centro de Biología Molecular Vegetal)
Ortega, Angélica (Universidad de Chile. Centro de Biología Molecular Vegetal)
González-Calquin, Christian (Universidad de Chile. Centro de Biología Molecular Vegetal)
Quiroz Iturra, Luis Felipe (Universidad de Chile. Centro de Biología Molecular Vegetal)
Moreno Romero, Jordi (Centre de Recerca en Agrigenòmica)
Martínez García, Jaime F. (Centre de Recerca en Agrigenòmica)
Stange, Claudia (Universidad de Chile. Centro de Biología Molecular Vegetal)

Date:	2022
Abstract:	Light stimulates carotenoid synthesis in plants during photomorphogenesis through the expression of PHYTOENE SYNTHASE (PSY), a key gene in carotenoid biosynthesis. The orange carrot (Daucus carota) synthesizes and accumulates high amounts of carotenoids in the taproot that grows underground. Contrary to other organs, light impairs carrot taproot development and represses the expression of carotenogenic genes, such as DcPSY1 and DcPSY2, reducing carotenoid accumulation. By means of RNA sequencing, in a previous analysis, we observed that carrot PHYTOCHROME RAPIDLY REGULATED1 (DcPAR1) is more highly expressed in the underground grown taproot compared with those grown in light. PAR1 is a transcriptional cofactor with a negative role in shade avoidance syndrome regulation in Arabidopsis (Arabidopsis thaliana) through the dimerization with PHYTOCHROME-INTERACTING FACTORs (PIFs), allowing a moderate synthesis of carotenoids. Here, we show that overexpressing AtPAR1 in carrot increases carotenoid production in taproots grown underground as well as DcPSY1 expression. The high expression of AtPAR1 and DcPAR1 led us to hypothesize a functional role of DcPAR1 that was verified through in vivo binding to AtPIF7 and overexpression in Arabidopsis, where AtPSY expression and carotenoid accumulation increased together with a photomorphogenic phenotype. Finally, DcPAR1 antisense carrot lines presented a dramatic decrease in carotenoid levels and in relative expression of key carotenogenic genes as well as impaired taproot development. These results suggest that DcPAR1 is a key factor for secondary root development and carotenoid synthesis in carrot taproot grown underground.
Grants:	Agencia Estatal de Investigación BIO2017-85316-R Agencia Estatal de Investigación PID2020-115782GB-I00 European Commission 797473
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, i la comunicació pública de l'obra, sempre que no sigui amb finalitats comercials, i sempre que es reconegui l'autoria de l'obra original. No es permet la creació d'obres derivades.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Subject:	Arabidopsis ; Carotenoids ; Daucus carota ; Gene Expression Regulation, Plant ; Phytochrome
Published in:	Plant physiology, Vol. 189, Issue 3 (July 2022) , p. 1450-1465, ISSN 1532-2548

DOI: 10.1093/plphys/kiac097
PMID: 35266544

16 p, 1.5 MB

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > CRAG (Centre for Research in Agricultural Genomics)
Articles > Research articles
Articles > Published articles