Comprehensive identification of NLP gene family in Panax ginseng:PgNLP02-01 and PgNLP07 genes expression analysis in ginseng adventitious roots under MeJA response.

Panax ginseng is a perennial plant of the Araliaceae family. Ginsenosides in ginseng are important secondary metabolites with extremely high economic value. The NLP family constitutes an important class of transcription factors in plants that participate in regulating plant growth, development, secondary metabolism, and other biological processes. In this study, we identified 20 members of the NLP gene family in ginseng. Analyses were performed on gene structure, chromosomal localization and collinearity relationships, phylogenetic relationships, expression patterns, and cis-acting elements. Three candidate genes were finally screened out through SNP/InDel association analysis with ginsenosides, correlation analysis between gene expression levels and ginsenoside contents, and co-expression analysis with key enzyme genes. The expression profiles of these three candidate genes under MeJA induction were investigated, and their correlations with ginsenoside content under the same treatment were further analyzed. Consequently, two genes (PgNLP02-01 and PgNLP07) associated with the regulation of ginsenoside biosynthesis were identified in this study. Co-expression trend analysis with 15 key enzyme genes revealed that the two genes negatively and positively regulated the expression of CYP716A53v2_1 and DS_1, respectively, thereby clarifying the potential regulatory mechanism underlying ginsenoside biosynthesis in ginseng.