Cannabis (Cannabis sativa L.) belongs to the Cannabaceae family and is one of the earliest cultivated crops, being of particular interest due to its multiple uses. In fact, it is characterized by an extensive set of compounds used in medicinal products and being a source of food and hemp fibre. Despite this, due to the legislation regulating Cannabis cultivation, it is a poorly characterized crop at molecular and genetic level. However, the recent easing of regulations, as well as the availability of Cannabis genome sequences, has allowed further research on this crop. The resulting increase in Cannabis production has led to an increase in the incidence, range and severity of diseases caused by crop pathogens, including the identification of previously unreported diseases. Few studies look into the molecular mechanisms involved in pathogen defense, thus the underlying biological pathways are poorly explored.
Here, we provide an overview on Cannabis defense responses against common pathogens, such as Golovinomyces spp., Fusarium spp., Botrytis cinerea and Pythium spp. For each of these pathogens, we illustrate the major symptoms in Cannabis and explore studies aiming to identify the genes involved in the resistance mechanisms of this crop. Omics studies allowing the identification of candidate defense genes are also underlined. Many of them focus on the potential involvement of disease resistance genes, while others draw comparisons with other species. Finally, genome editing approaches to generate disease resistant Cannabis species are discussed.
To the best of our knowledge, this is the first study about molecular mechanisms underlying pathogen resistance in Cannabis.