GA3-AM is a cell permeable analog of the plant hormone gibberellic acid that acts as a chemical dimerizer or chemical inducer of dimerization. GA3 and rapamycin chemically inducible dimerization systems are orthogonal. GA3-AM has been used in conjunction with a rapamycin dimerization system and CRISPR/Cas9 activators for temporal control of CRISPR/Cas9 activator function, enabling temporal regulation of multiple genes.