OpNAC1 transcription factor regulates the biosynthesis of the anticancer drug camptothecin by targeting loganic acid O-methyltransferase in Ophiorrhiza pumila.
J Integr Plant Biol
; 65(1): 133-149, 2023 Jan.
Article
en En
| MEDLINE
| ID: mdl-36194508
Camptothecin (CPT) is an anticancer pentacyclic quinoline alkaloid widely used to treat cancer patients worldwide. However, the biosynthetic pathway and transcriptional regulation of camptothecin are largely unknown. Ophiorrhiza pumila, the herbaceous plant from the Rubiaceae family, has emerged as a model plant for studying camptothecin biosynthesis and regulation. In this study, a high-quality reference genome of O. pumila with estimated size of ~456.90 Mb was reported, and the accumulation level of camptothecin in roots was higher than that in stems and leaves. Based on its spatial distribution in the plant, we examined gene functions and expression by combining genomics with transcriptomic analysis. Two loganic acid O-methyltransferase (OpLAMTs) were identified in strictosidine-producing plant O. pumila, and enzyme catalysis assays showed that OpLAMT1 and not OpLAMT2 could convert loganic acid into loganin. Further knock-out of OpLAMT1 expression led to the elimination of loganin and camptothecin accumulation in O. pumila hairy roots. Four key residues were identified in OpLAMT1 protein crucial for the catalytic activity of loganic acid to loganin. By co-expression network, we identified a NAC transcription factor, OpNAC1, as a candidate gene for regulating camptothecin biosynthesis. Transgenic hairy roots and biochemical assays demonstrated that OpNAC1 suppressed OpLAMT1 expression. Here, we reported on two camptothecin metabolic engineering strategies paving the road for industrial-scale production of camptothecin in CPT-producing plants.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Rubiaceae
/
Antineoplásicos
/
Antineoplásicos Fitogénicos
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
J Integr Plant Biol
Año:
2023
Tipo del documento:
Article
País de afiliación:
China
Pais de publicación:
China