Fig. 1.

Hormone function in root growth. Indicated are the supportive or inhibitory effects of the different hormones on growth in the meristematic zone (MZ), transition zone (TZ), and elongation zone (EZ). The effect of these hormones on cell division in the MZ and endoreplication via the endocycle is unknown for most hormones (?). ABA, abscisic acid; AUX, auxin; BR, brassinosteroids; CK, cytokinins; ET, ethylene; GA, gibberellins; JA, jasmonates; SA, salicylic acid; SL, strigolactone; TOR, target of rapamycin; SNRK1, Snf1-related AMP-activated kinase.