Plant age-dependent dynamics of annatto pigment (bixin) biosynthesis in Bixa orellana

Author(s):Show less -

Machado, Kleiton Lima de Godoy ; Faria, Daniele Vidal ; Duarte, Marcos Bruno Silva ; Silva, Lazara Aline Simoes ; de Oliveira, Tadeu dos Reis ; Falcao, Thais Castilho Arruda ; Batista, Diego Silva ; Costa, Marcio Gilberto Cardoso ; Santa-Catarina, Claudete ; Silveira, Vanildo ; Romanel, Elisson ; Otoni, Wagner Campos ; Nogueira, Fabio Tebaldi Silveira

• Document type: Journal article
• Source: Journal of Experimental Botany; v. 75, n. 5, p. 17-pg., 2023-12-08.

Abstract

Age affects the production of secondary metabolites, but how developmental cues regulate secondary metabolism remains poorly understood. The achiote tree (Bixa orellana L.) is a source of bixin, an apocarotenoid used in diverse industries worldwide. Understanding how age-dependent mechanisms control bixin biosynthesis is of great interest for plant biology and for economic reasons. Here we overexpressed miRNA156 (miR156) in B. orellana to comprehensively study the effects of the miR156-SQUAMOSA PROMOTER BINDING PROTEIN-LIKE (SPL) module on age-dependent bixin biosynthesis in leaves. Overexpression of miR156 in annatto plants (miR156ox) reduced BoSPL transcript levels, impacted leaf ontogeny, lessened bixin production, and increased abscisic acid levels. Modulation of expression of BoCCD4-4 and BoCCD1, key genes in carotenoid biosynthesis, was associated with diverting the carbon flux from bixin to abscisic acid in miR156ox leaves. Proteomic analyses revealed an overall low accumulation of most secondary metabolite-related enzymes in miR156ox leaves, suggesting that miR156-targeted BoSPLs may be required to activate several secondary metabolic pathways. Our findings suggest that the conserved BomiR156-BoSPL module is deployed to regulate leaf dynamics of bixin biosynthesis, and may create novel opportunities to fine-tune bixin output in B. orellana breeding programs. Age affects the production of secondary metabolites: miR156 and likely its main targets, BoSPLs , modulate the age-dependent biosynthesis of the apocarotenoid bixin, a product used in diverse industries. (AU)

• FAPESP's process: 18/17441-3 - Molecular control of shoot architecture: interplay between microRNAs, transcription factors and phytohormones
• Grantee: Fabio Tebaldi Silveira Nogueira
• Support Opportunities: Research Projects - Thematic Grants