Strigolactone signaling in the endodermis is sufficient to restore root responses and involves SHORT HYPOCOTYL 2 (SHY2) activity.

Strigolactones (SLs) are plant hormones and regulators of root development, including lateral root (LR) formation, root hair (RH) elongation and meristem cell number, in a MORE AXILLARY GROWTH 2 (MAX2)-dependent way. However, whether SL signaling is acting cell-autonomously or in a non-cell-autonomous way in roots is unclear. We analyzed root phenotype, hormonal responses and gene expression in multiple lines of Arabidopsis thaliana max2-1 mutants expressing MAX2 under various tissue-specific promoters and shy2 mutants.