| Ginseng industry is an important economic pillar in the eastern mountainous area of Jilin province.Great progress has been made in the basic and applied research on ginseng cultivation,chemical composition,pharmacological effect and product development.However,the modern biology of ginseng,especially the research and application of ginseng functional genomics is seriously lagging behind,which restricts the in-depth analysis of some biological processes in the growth and development of ginseng,and restricts the development and application of modern biotechnologies such as ginseng molecular design and breeding and ginseng synthetic biology.MADS-box transcription factors are one of the most important families in plants.Up to now,there are more and more researches on this family,and play an important role in regulating root formation,flower development and response to abiotic stress of plants.At present,MADS-box transcription factors have been deeply studied in Arabidopsis thaliana,rice and wheat,but not in ginseng.In this study,MADS-box transcription factors were identified and analyzed systematically based on 248,993 Unigenes databases of Jilin ginseng.A MADS-box gene highly related to growth and development in ginseng was identified,and its function was verified,which fills the blank in the research on MADS-box transcription factors in ginseng.The obtained results are as follows:1.In this study,160 PgMADSs transcripts were identified in Jilin ginseng and analyzed systematically.It was found that PgMADSs could be divided into 10 subfamilies and 20 motifs,PgMADSs are relatively conserved during evolution.2.GO analysis showed that PgMADSs was at level 2 Biological process(BP),molecular function(MF)and cellular component(CC)were all annotated into 12 subfunctions,10 of which had significant enrichment.The results indicate functional similarities among the PgMADSs genes,and diverse functional directions of PgMADSs gene population.3.The expression analysis in native varieties and roots at different ages revealed specific expression of PgMADSs transcripts in different tissues.Additionally,the results demonstrated that the expression of PgMADSs gene was different in different tissues and roots at different ages.The interaction network analysis of PgMADSs stranscripts showed that PgMADSs coordinated with each other and played a synergistic effect.4.PgMADS17-04 was screened as a candidate gene through bioinformatics analysis for next research.5.Through the analysis of the PgMADSs gene under abiotic stress,it was found that the PgMADS17-04 gene was significantly up-regulated under all 6 stresses,among which the response to cold stress was the most significant.This indicates that the PgMADS17-04 gene may have a very important role in the response to ginseng stress,and may also play an important role in the growth and development process.6.To further verify the important function of the PgMADS17-04 gene in ginseng,the overexpression vector of the PgMADS17-04 gene was successfully constructed.Genetic transformation was carried out on the adventitious root of ginseng using agrobacterium rhizogenes-mediated transformation,and successfully induced single-root clones of positive ginseng hairy roots,laying a foundation for further research on the function of PgMADS17-04 gene.7.The ginsenoside content of hairy root lines overexpressing overexpressing PgMADS17-04 was investigated by HPLC.It was found that PgMADS17-04 may affect the synthesis of monomeric saponins and promote the synthesis of total glycosides.8.After low temperature treatment of overexpression hairy roots and wild-type hairy roots,the MDA content of overexpression lines decreased.It indicates that the PgMADS17-04 gene may play an important role in the response of ginseng hairy roots to resist the cold stress environment.9.The content of four monomeric saponins Rg1,Rf,Rd and Rg3 in positive hairy roots increased significantly under low temperature stress,preliminarily indicating that the PgMADS17-04 gene not only promotes the biosynthesis of ginsenosides but also responds to cold stress. |
