The gaseous plant growth regulator is used in plants to:

Ethylene is a gaseous plant growth regulator, synthesised by most ripening fruits and ageing tissues. Ethylene is used as both plant growth promoters and plant growth inhibitors. It is mainly used to stimulate the ripening of fruits. It also promotes root growth and root hair formation to increase the absorption surface. Cytokinin can overcome apical dominance caused by auxin. Synthetic auxin kill dicotyledonous weeds in the fields. Gibberellins are used to speed up the malting process in brewing industry.