The NAC Transcription Factor PgNAC41-2 Gene Involved in the Regulation of Ginsenoside Biosynthesis in Panax ginseng

Abstract

Ginseng (Panax ginseng C.A. Meyer) is a perennial herb of the Araliaceae family, a traditional and valuable Chinese herb in China. The main active component of ginseng is ginsenoside. The NAC transcription factors belong to a large family of plant-specific transcription factors, which are involved in growth and development, stress response and secondary metabolism. In this study, we mapped the NAC gene family on 24 pairs of ginseng chromosomes and found numerous gene replications in the genome. The NAC gene PgNAC41-2, found to be highly related to ginsenoside synthesis, was specifically screened. The phylogeny and expression pattern of the PgNAC41-2 gene were analyzed, along with the derived protein sequence, and a structure model was generated. Furthermore, the PgNAC41-2 gene was cloned and overexpressed by a Rhizobium rhizogenes mediated method, using ginseng petioles as receptor material. The saponin content of the transformed material was analyzed to verify the function of the NAC transcription factor in ginseng. Our results indicate that the PgNAC41-2 gene positively regulates the biosynthesis of saponins.

Comprehensive Analysis of NAC Transcription Factors Reveals Their Evolution in Malvales and Functional Characterization of AsNAC019 and AsNAC098 in Aquilaria sinensis

“…Twelve SbNACs are involved in regulating the synthesis of flavonoids in the flowers of Scutellaria baicalensis [27]. PgNAC41-2 positively regulates the biosynthesis of saponins in Panax ginseng [28] and the NAC family acts as a regulatory effector in the synthesis of a variety of metabolites under salt stress in Isatis indigotica [29]. However, a systematic study on the NAC gene family has not yet been clearly defined in Malvales, especially in Aquilaria sinensis.…”