Plant–pathogen interaction with root rot of Panax notoginseng as a model: Insight into pathogen pathogenesis, plant defence response and biological control

Plant diseases are a major threat affecting the sustainability of global agriculture. Although the breeding of new resistant cultivars is considered to be the primary approach to prevent and control plant diseases, it is dependent on an in-depth understanding of plant–pathogen interactions. At present, we have an in-depth understanding of the interactions between model plants and pathogens, such as Arabidopsis thaliana and rice, but we are still in the beginning stage for more non-model plants (e.g., medicinal plants). Panax notoginseng is the primary source of the high-value active ingredient triterpenoid saponins. Root rot disease in P. notoginseng has attracted research attention because of its high destructiveness. Understanding the infection stages and strategies of pathogens, plant resistance mechanisms and induced plant defence against pathogens is essential to support agricultural sustainable development of P. notoginseng. Here, we review and summarize, with root rot of P. notoginseng as a model, the current knowledge of plant–pathogen interaction, and feasability of use of microorganisms and secondary metabolites as sources of biological control agents at a low cost. Finally, we also discuss the importance of plant–pathogen interactions in resistance breeding, thereby providing a new strategy to develop green agriculture for non-model plants.