Bioactivity of Raphanus Species against Agricultural Phytopathogens and its Role in Soil Remediation: A Review

Phytopathogens and weeds represent around 20-40% of global agricultural productivity losses. Synthetic pesticide products are the most used to combat these pests, but it reiterates that their use has caused tremendous pressure on ecosystems' self-cleansing capacity and resistance development by pathogens to synthetic fungicides. In the last decades, researchers have demonstrated the vast biological properties of plants against pathogens and diseases. Raphanus species (Brassicaceae) possesses antimicrobial, antioxidant, anti-inflammatory, anticancer, hepatoprotective, antidiabetic, insecticidal, nematicidal, allelopathic, and phytoremediators properties. These are due to the presence of structurally diverse bioactive compounds, such as flavonoids and glucosinolates. In this review, we have provided an update on the biological properties of two Raphanus species (R. sativus and R. raphanistrum), detailing the type of natural product (extract or isolated compound), the bioassays displayed, and the results obtained for the main bioactivities of this genus cited in the literature during the last 30 years. Moreover, preliminary studies on phytopathogenic activities performed in our laboratory have also been depicted. We conclude that Raphanus species could be a source of natural bioactive molecules to treat phytopathogens and weeds that affect crops and remediate contaminated soils.