β-cyclocitral is a conserved root growth regulator (bioRxiv)

Enhancing root growth can aid plant survival in challenging environments such as salty soils. Dickinson et al. built upon a previous study that identified D15, an inhibitor of lateral root development. They treated roots with D15 and also components of a small-molecule library to search for suppressors of the suppressor: plants with restored root growth. They identified β-cyclocitral, a metabolite of β-carotene. Using several reporter lines, the authors found that β-cyclocitral enhances pre-emergence growth of lateral root primordia by stimulating meristematic cell divisions. The root-enhancing effects of β-cyclocitral occurr in the absence of D15 as well, and in rice as well as Arabidopsis, even in the presence of salt stress. These results indicate that β-cyclocitral could have applications in enhancing crop growth in adverse conditions. (Summary by Mary Williams) bioRxiv 10.1101/337162