Vol.:(0123456789) 1 3 Plant Cell, Tissue and Organ Culture (PCTOC) https://doi.org/10.1007/s11240-020-01857-8 RESEARCH NOTE 5‑Azacytidine downregulates the SABATH methyltransferase genes and augments bixin content in Bixa orellana L. leaves Daniele Vidal Faria 1  · Ludmila Nayara de Freitas Correia 1  · Diego Silva Batista 2  · Camilo Elber Vital 1  · Angelo Schuabb Heringer 3  · Clelia De‑la‑Peña 4  · Marcio Gilberto Cardoso Costa 5  · Miguel Pedro Guerra 3  · Wagner Campos Otoni 1 Received: 14 April 2020 / Accepted: 26 May 2020 © Springer Nature B.V. 2020 Abstract Bixa orellana L. seeds are an important source of the liposoluble apocarotenoid bixin and the natural hydrosoluble dye norbixin. These natural dyes are used for food, pharmaceutical, and cosmetic applications. The participation of methyltrans- ferases has already been demonstrated in the bixin biosynthesis pathway, and the alteration of these genes expression can lead to changes in the production of bixin. Treatment with demethylating agents, such as 5-azacytidine (5-AzaC), was previously related to an increased production of secondary compounds and serves for the study of secondary metabolism pathways in plants. Here, we evaluated for the frst time the efect of 5-AzaC on the expression of SABATH methyltransferase genes as well as some bixin pathway candidate genes, global DNA methylation, and bixin, chlorophylls, and total carotenoid content in the leaves of B. orellana plants cultured in vitro. Exposing shoot apexes to 5-AzaC for 48 h afected global genome methylation but did not alter chlorophylls and total carotenoid content in the leaves of B. orellana. Importantly, plants submitted to this demethylating agent exhibited downregulation of the SABATH and CCD4 families of genes, upregulation of the ALDH3H1 gene, and increased bixin content in the leaves, suggesting that this methyltransferase inhibitor can selectively regulate the biosynthesis and production of bixin in B. orellana by an unknown mechanism. Moreover, here we demonstrate the pos- sibility to use 5-AzaC to increase bixin contents in B. orellana plants. Key message The methyltransferase inhibitor, 5-Azacytidine, can selectively regulate the biosynthesis and production of bixin in annatto plant leaves, by upregulating BoALDH3H1 gene and downregulating BoSABATH and BoCCD4 gene families. Keywords 5-Azacytidine · Annatto · Bixin pathway · Methyltransferase inhibitor · SABATH genes Abbreviations 5-AzaC 5-Azacytidine ALDH Aldehyde dehydrogenase BoADH Bixin aldehyde dehydrogenase BoLCD Bixin carotene cleavage dioxygenase BonBMT Norbixin methyltransferase CCD4 Carotenoid cleavage dioxygenase 4 Communicated by Manoj Prasad. Electronic supplementary material The online version of this article (https://doi.org/10.1007/s11240-020-01857-8) contains supplementary material, which is available to authorized users. * Wagner Campos Otoni wcotoni@gmail.com 1 Departamento de Biologia Vegetal/Laboratório de Cultura de Tecidos/BIOAGRO, Universidade Federal de Viçosa, Campus Universitário, Avenida Peter Henry Rolfs s/n, Viçosa, MG 36570-900, Brazil 2 Departamento de Agricultura, Universidade Federal da Paraíba, Campus III, Bananeiras, PB 58220-000, Brazil 3 Laboratório de Fisiologia do Desenvolvimento e Genética Vegetal, Centro de Ciências Agrárias, Universidade Federal de Santa Catarina, Florianópolis, SC 88034-001, Brazil 4 Unidad de Biotecnología, Centro de Investigación Científca de Yucatán, A. C. (CICY), 97205 Mérida, Yucatán, México 5 Departamento de Ciências Biológicas, Universidade Estadual de Santa Cruz, Ilhéus, BA 45662-900, Brazil