| Codonopsis pilosula is one of the major medicinal materials used in both medicine and food.Codonopsis pilosula is susceptible to root rot in cultivation.The main pathogen of root rot is Fusarium oxysporum.Therefore,through Fusarium oxysporum infection test,we found that the activity of antioxidant enzymes in Codonopsis pilosula plant tissues increased during the infection of the pathogen.Transcriptome analysis was performed on tissue samples infected with pathogens to study the molecular mechanism of Codonopsis pilosula in response to Fusarium oxysporum stress at five time points.Functional analysis of differentially expressed genes showed that genes involved in hormone signal transduction,mitogen activated protein kinase(MAPK)signal transduction and plant-pathogen interaction were highly expressed in Codonopsis pilosula in response to Fusarium oxysporum infection.The Sn RK2 family members responding to abscitic acid were identified based on the transcriptome data of Codonopsis pilosula response to Fusarium oxysporum,and a total of six genes were obtained.Then,bioinformatics methods were used to comprehensively analyzed.It was found that the six Cp Sn RK2 genes were divided into three subfamilies,each with similar motifs and presumably with similar functions.The expression levels of Cp Sn RK2.4 and Cp Sn RK2.6 genes gradually increased in response to Fusarium oxysporum stress,indicating that these two genes played a key role in the response to Fusarium oxysporum stress.It was found that Sn RK2 gene interacted with WRKY,MYB,ERF and b HLH transcription factors to regulate the response of Codonopsis pilosula to Fusarium oxysporum.Based on transcriptome data of Codonopsis pilosula in response to Fusarium oxysporum,10 Cp MAPK genes were identified.After comprehensive bioinformatics analysis,it was found that these 10 genes were divided into four subfamilies(A,B,C and D),and the motif distribution of each subfamily was similar.It indicating that they had similar functions.The expression of Cp MAPK genes was time-specific in response to Fusarium oxysporum stress,and the expression levels of TRINITY＿DN53318＿c1＿g1 and TRINITY＿DN60430＿c0＿g1 increased gradually in response to Fusarium oxysporum stress.The Cp MAPK gene could interact with MKK,MKKK and WRKY to jointly regulate the response of Codonopsis pilosula to Fusarium oxysporum.In addition,transient Cp MAPK9 expression increased the contents of jasmonic acid(JA)and salicylic acid(SA)in Codonopsis pilosula leaves.It is speculated that Cp MAPK9 and hormone may participate in the response of Codonopsis pilosula to Fusarium oxysporum.This study provided a theoretical basis for studying the molecular mechanism of disease resistance of Codonopsis pilosula,a basis for cultivating highly resistant varieties of Codonopsis pilosula,and an effective strategy for the development of green economy of Codonopsis pilosula industry. |
