Tetraose glycoalkaloids from potato can provide complete protection against fungi and insects

Plants with innate disease and pest resistance can contribute to more sustainable agriculture. Resistance breeding typically relies on the use of immune receptors or impaired susceptibility genes, but these come with challenges in terms of strength, durability or pleotropic effects. Natural defence compounds from plants are not considered in breeding, because biosynthesis of these compounds is a complex trait and proof of their role in resistance is often indirect. Here, we identified a wild relative of potato, Solanum commersonii, that provides us with unique insight in the role of glycoalkaloids in plant immunity. We cloned two atypical resistance genes that can provide complete resistance to Alternaria solani and Colorado potato beetle through the production of tetraose steroidal glycoalkaloids. Moreover, we show that these compounds are active against a wide variety of fungi. This research highlights the potential of using natural defence compounds produced by plants to protect them against pests and diseases.