Harnessing the strigolactone biosynthesis mutant lgs1 to combat food insecurity in Africa

Sorghum is a food staple for millions of people in sub-Saharan Africa, but parasitic weeds of the Striga genus greatly diminish its production. An efficient and cost-effective way of managing Striga in smallholder farms in Africa is to deploy resistant varieties. Here, we leverage genomics and the vast genetic diversity of sorghum – evolutionarily adapted to cope with Striga parasitism in Africa – to identify new Striga-resistant sorghum genotypes. We exploit a Striga resistance mechanism that hinges on essential communication molecules – strigolactones exuded by hosts to trigger parasite seed germination. We used the Sorghum Association Panel (SAP) to search for sorghum genotypes with a mutation on the LOW GERMINATION STIMULANT 1 ( LGS1) locus that makes them ineffective in inducing Striga germination. Our analysis led us to identify new lgs1 sorghum genotypes which we named SAP lgs1. SAP lgs1 had the SL exudation profile of known lgs1 sorghum whose hallmark is the production of the low inducer of germination, orobanchol. Laboratory and field resistance screens showed that the SAP lgs1 genotypes also exhibited remarkable resistance against Striga. Our findings have far-reaching implications for improving food security in Africa by potentially reducing crop losses due to Striga parasitism.