Abstract
Natural compounds capable of increasing root depth and branching are desirable tools for enhancing stress tolerance in crops. We devised a sensitized screen to identify natural metabolites capable of regulating root traits in Arabidopsis. Application of nanomolar concentrations of β-cyclocitral were found to promote cell divisions in root meristems, stimulating branching and growth. β-cyclocitral had a conserved effect on root growth in tomato and rice. β-cyclocitral fundamentally altered root system architecture in rice, generating deeper and more compact root systems without affecting shoot growth. Importantly, β-cyclocitral treatment enhanced root growth under abiotic stress conditions in rice. These results indicate that β-cyclocitral is a conserved regulator of root growth across monocots and dicots and could be a valuable tool to shield crops from environmental stress.
One Sentence Summary β-cyclocitral, a metabolite of β-carotene, was identified as a conserved enhancer of root growth and branching using a sensitized chemical screen.