[Screening and expression analysis of transcription factors involved in genuineness of Codonopsis pilosula in Shanxi].

This study aims to mine the transcription factors that affect the genuineness of Codonopsis pilosula in Shanxi based on the transcriptome data of C. pilosula samples collected from Shanxi and Gansu, and then analyze the gene expression patterns, which will provide a theoretical basis for the molecular assisted breeding of C. pilosula. Gene ontology(GO) functional annotation, conserved motif prediction, and gene expression pattern analysis were performed for the differential transcription factors predicted based on the transcriptome data of C. pilosula from different habitats. A total of 61 differentially expressed genes(DEGs) were screened out from the transcriptome data. Most of the DEGs belonged to AP2/ERF-ERF family, with the conserved motif of [2X]-[LG]-[3X]-T-[3X]-[AARAYDRAA]-[3X]-[RG]-[2X]-A-[2X]-[NFP]. Forty-three of the DEGs showed significantly higher gene expression in C. pilosula samples from Shanxi than in the samples from Gansu, including 11 genes in the AP2/ERF-ERF family, 5 genes in the NAC fa-mily, 1 gene in the bHLH family, and 2 genes in the RWP-RK family, while 18 transcription factors showed higher expression levels in the samples from Gansu. GO annotation predicted that most of the DEGs were enriched in GO terms related to transcriptional binding activity(103), metabolic process(26), and stress response(23). The expression of transcription factor genes, CpNAC92, CpNAC100, CpbHLH128, and CpRAP2-7 was higher in the samples from Shanxi and in the roots of C. pilosula. CpNAC92, CpbHLH128, and CpRAP2-7 responded to the low temperature, temperature difference, and iron stresses, while CpNAC100 only responded to low temperature and iron stresses. The screening and expression analysis of the specific transcription factors CpNAC92, CpNAC100, CpbHLH128, and CpRAP2-7 in C. pilosula in Shanxi laid a theoretical foundation for further research on the mechanism of genuineness formation of C. pilosula.

Establishment of a genetic transformation system for Codonopsis pilosula callus.

Codonopsis pilosula, a traditional Chinese medicinal and edible plant, contains several bioactive components. However, the biosynthetic mechanism is unclear because of the difficulties associated with functional gene analysis. Therefore, it is important to establish an efficient genetic transformation system for gene function analysis. In this study, we established a highly efficient Agrobacterium-mediated callus genetic transformation system for C. pilosula using stems as explants. After being pre-cultured for 3 days, the explants were infected with Agrobacterium tumefaciens strain GV3101 harboring pCAMBIA1381-35S::GUS at an OD600 value of 0.3 for 15 min, followed by co-cultivation on MS induction medium for 1 day and delayed cultivation on medium supplemented with 250 mg l-1 cefotaxime sodium for 12 days. The transformed calli were selected on screening medium supplemented with 250 mg l-1 cefotaxime sodium and 2.0 mg l-1 hygromycin and further confirmed by PCR amplification of the GUS gene and histochemical GUS assay. Based on the optimal protocol, the induction and transformation efficiency of calli reached a maximum of 91.07%. The establishment of a genetic transformation system for C. pilosula calli lays the foundation for the functional analysis of genes related to bioactive components through genetic engineering technology.