Rhizomes are underground stems serving as storage organs and containing meristematic tissues which are capable of generating shoots and roots. However, the mechanisms controlling rhizome formation and growth are not yet completely understood.

Phenotypes of ‘BR’ tall fescue.
Phenotypes of ‘BR’ tall fescue. (Left) Rhizomatous phenotypes that had been grown in fritted clay for 3 months in the greenhouse. (Centre) A rhizome bud was observed 3 d after transplanting to the hydroponic system. (Right) Rhizomatous phenotypes in hydroponics after 12 d in the growth chamber.

Ma et al. find that cytokinins (CK) and gibberellins (GA) promoted rhizome formation and growth, respectively, through activating genes and proteins in metabolic pathways that supply energy and amino acids to support cell division and expansion during rhizome initiation and elongation in tall fescue (Festuca arundinacea).