Pleiotropic properties of GOLDEN2-LIKE transcription factors for crop improvement

Crop improvement can be affected by enhancing the efficiency of photosynthesis-associated bioprocesses such as chlorophyll biosynthesis, chloroplast biogenesis, the functioning of photosystems including light-harvesting complexes, and carbon fixation. To achieve this, the GOLDEN2-LIKE (GLK) transcription factors represent promising targets since they play a positive role for greening traits in diverse plants. To scrutinize the pleiotropic impact of GLKs, we summarized all phenotypic traits reported in functional studies that used transgenic approaches to lose or gain gene functions. Additionally, we also discussed altered plant phenotypes with respect to their physiological–biochemical aspects and environmental stress responses. From these results, we conclude that GLKs consistently increase chlorophyll biosynthesis, enhance chloroplast division, and increase photosynthetic rate. They individually influence other traits including yield, phytochemical accumulation, and biotic and abiotic stress resistance. Collectively, GLKs have potential as key regulators to effect increases in overall agricultural quality across plant species. This suggests that they may be among the most promising target genes for future agro-biotechnology applications.