Deciphering the transcriptomic response of Ilyonectria robusta in relation to Ginsenoside Rg1 treatment and the development of panax ginseng rusted root disease

Abstract

Rust rot is a severe Panax ginseng disease caused by Ilyonectria robusta . The severity of the disease is related to the content of residual ginsenoside content in the soil. Herein, the effects of different concentrations of ginsenoside Rg1 on ginseng rust rot and its pathogens were studied, and the growth and sporulation of fungi cultured in vitro were determined. The results showed that Rg1 significantly promoted the mycelial growth, and sporulation compared to the control, and aggravated the disease symptoms of Panax ginseng . A total of 6,708 transcripts out of 213,131 annotated genes identified from global transcriptomic analysis were differentially expressed in I.robusta grown in the Rg1 treatment. These genes were found to be related to the carbon-nitrogen metabolism, transport, and assimilation. Many of these genes were also associated with pathogenicity based on the Phi-base database. Several transcription factors were related to specific biological processes, such as nitrogen utilization. The current results revelation that Rg1 plays a major role in the development of rust rot by promoting fungal cell growth and affecting the expression of genes required for pathogenesis. Rg1 could aggravate the invasion of I.robusta on ginseng root, which preliminarily revealed the reason for the aggravation of rust rot in ginseng c ontinuous cropping obstacle.