Molecular Action of GOLDEN2-LIKE Transcription Factor Family with Diverse Interacting Promoters and Proteins

GOLDEN2-LIKE (GLK) transcription factors belong to the GARP superfamily and are known as major positive regulators of greening in various plants, including Arabidopsis, rice, maize, tomato, and moss. Recent studies have reported many GLK downstream targets and binding partners. This revealed the breadth of GLK-related downstream pathways and its multiplexed-regulatory system beyond greening regulation. To evaluate the complexity of the molecular mode of action of GLKs, here we summarize the current knowledge of the interactions from promoters of direct GLK downstream target genes involved in chlorophyll biosynthesis, photosystem I, photosystem II, catechin biosynthesis, flowering, and abscisic acid signaling, and proteins that directly bind to GLKs, including kinases, E3 ligases, repressors of GLK activity, histone deacetylases, transcriptional coregulators, and transcription factors. This overview of GLK-related pathways supports the pleiotropic function of GLKs as core regulators of a multi-regulatory system involving plant greening and other phenotypes.