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 methyltransferases 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 first time the effect 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 affected 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 possibility to use 5-AzaC to increase bixin contents in B. orellana plants.

Bixa orellana L.种子是脂溶性类胡萝卜素类联蛋白和天然水溶性染料Norbixin的重要来源。这些天然染料可用于食品，药品和化妆品。甲基转移酶的参与已在bixin生物合成途径中得到证实，而这些基因表达的改变可导致bixin产生的变化。以前用脱甲基剂（例如5-氮杂胞苷（5-AzaC））处理与增加次级化合物的产量有关，并用于研究植物中的次级代谢途径。在这里，我们首次评估了5-AzaC对SABATH表达的影响甲基化转移酶基因以及一些bixin途径候选基因，整体DNA甲基化以及体外培养的B. orellana植物叶片中的bixin，叶绿素和总类胡萝卜素含量。将芽尖暴露于5-AzaC 48小时会影响总体基因组甲基化，但不会改变B. orellana叶片中的叶绿素和总类胡萝卜素含量。重要的是，接受该脱甲基剂处理的植物表现出SABATH和CCD4基因家族的下调，ALDH3H1基因的上调以及叶片中二恶英含量的增加，表明该甲基转移酶抑制剂可以选择性地调节B中生物素的合成和生产。奥雷利亚纳通过未知的机制。此外，在这里，我们证明了使用5-AzaC来增加B. orellana植物中联蛋白含量的可能性。