Expression Patterns and Functional Analysis of Pathogenesis-related Protein PnPR1 Gene of Panax notoginseng

Abstract

In this study, we used quantitative reverse transcription-PCR to analyze the expression level of PnPR1, a pathogenesis-related protein gene of Panax notoginseng. In addition, the overexpression vector of pCAMBIA2300s-PnPR1 was constructed and then introduced into tobacco (Nicotiana tabacum ) with Agrobacterium tumefaciens mediated method. The results showed that: (1) the methyl jasmonate pretreatment of P . notoginseng roots greatly up-regulated the PnPR1 expression during Fusarium solani infection. (2) The expression level of PnPR1 gene was induced by the treatment of four signal molecules (methyl jasmonate, ethephon, salicylic acid, and hydrogen peroxide) to varying degrees. The expression of PnPR1 was down-regulated by three kinds of signal molecule inhibitors. (3) PnPR1 was stably expressed in T2 transgenic tobacco, and the resistance of transgenic tobacco lines to F. solani was significantly improved. In conclusion, the PnPR1 gene responds to the infection of F. solani at transcription level and was induced by signal molecules such as methyl jasmonate. Overexpression of PnPR1 in tobacco lines enhanced the resistance to F. solani, indicating that PnPR1 is a disease-resistance gene involved in the defense responses of P . notoginseng to F. solani.