Abstract: To reveal the regulatory mechanism of defense response in Panax notoginseng (Burk) FH Chen against diseases,a NAC transcription factor gene was cloned from P.notoginseng,and its expression pattern was analyzed in the present study. One year old P.notoginseng seedlings were used as materials. According to an Unigene from P.notoginseng transcriptome which encoded a NAC transcription factor,the gene-specific primers were designed. Using the rapid amplification of cDNA end technology,a new NAC transcription factor gene of P.notoginseng was obtained which was named PnNAC1. The cDNA sequence of PnNAC1 was 815 bp in length and contained an intact open reading frame (ORF) of 576 bp,a 24 bp 5'-untranslated region (UTR),and a 215 bp 3'-UTR. The ORF of PnNAC1 encoded a putative protein with 191 amino acid residues which had a conserved NAC domain. Real-time PCR results indicated that pre-treatment with methyl jasmonate to roots of P.notoginseng seedlings increased the transcription level of PnNAC1 in roots,then the transcription level of PnNAC1 was further risen after inoculation with Fusarium solani,and its expression level was maximal at 4 h post inoculation with F.solani. For the control (pretreatment with sterile water), PnNAC1 also rapidly responded to infection of F.solani,but its expression level was evidently lower than that in samples which were pre-treated with methyl jasmonate. Moreover,the expression of PnNAC1 was inhibited in the leaves after inoculation with Alternaria panax. Furthermore,the transcription level of PnNAC1 was induced by treatment with four kinds of signaling molecules including methyl jasmonate,ethylene,salicylic acid,and hydrogen peroxid. The above results suggest that PnNAC1 responds to several stress-related signaling molecules and is involved in the defense response of P.notoginseng against the infection of F.solani and A. panax.

Key words: Panax notoginseng, NAC transcription factor, Fusarium solani, Alternaria panax, Defense response

CLC Number: 

• S567.03

• Q78