Wheat is an essential crop for global food security and is well adapted to a wide variety of soils1. However, the gene networks regulating different root architectures remain poorly understood. We report here the identification of a cluster of a monocot-specific12-OXOPHYTODIENOATE REDUCTASEgenes from subfamily III (OPRIII) that modulate key differences in wheat root architecture associated with grain yield under water-limited conditions. Wheat plants with a loss-of-function mutation inOPRIIIshowed longer seminal roots, whereas plants with increasedOPRIIIdosage or transgenic over-expression showed reduced seminal root growth, precocious development of lateral roots and increased jasmonic acid (JA). A JA-biosynthesis inhibitor eliminated the root differences, confirming a JA-mediated mechanism. Multiple transcriptome analysis of transgenic and wild-type lines revealed significant enriched JA-biosynthetic and reactive oxygen species (ROS) pathways that paralleled changes in ROS distribution. TheOPRIIIgenes provide a useful entry point to engineer root architecture in wheat and other cereals.
