Hydroxamic acids in maize resistance to Striga hermonthica. undefined

Striga hermonthica is the most widespread and destructive plant parasite infesting maize and other major crops in sub-Saharan Africa where it causes severe yield losses and threatens food security1. A few tolerant maize lines supporting reduced S. hermonthica emergence have been deployed2–4. However, the molecular bases of such resistance are yet poorly understood. Here, we show a previously unknown strategy of maize post-attachment resistance based on DIMBOA accumulation in infested roots. S. hermonthica infestation triggers positive regulation of gene expression in the hydroxamic acid (HA) pathway culminating with accumulation of benzoxazinoids (BX), known for their antifeedant, insecticidal, antimicrobial, and allelopathic activities5. HA root content is positively correlated to S. hermonthica resistance in resistant and progeny lines and in unrelated maize line. Downregulation of HA genes causes increased susceptibility to S. hermonthica infestation in loss-of-function maize mutants. The mechanism of BX action in parasitic plant resistance is yet to be uncovered but the potential of this discovery for development of effective control and breeding strategies is enormous.