Multifaceted roles of GRAS transcription factors in growth and stress responses in plants

The GAI-RGA- and -SCR (GRAS) proteins regulate a myriad of biological functions in plants. The C-terminus of GRAS proteins is highly conserved, whereas the N-terminus is hypervariable. So far, GRAS proteins have been reported in more than 50 plant species. However, not many GRAS proteins are characterized, thus limiting the revelation of their many functions. This review provides a recent update on GRAS proteins, including their structural features, evolutionary gene family expansion/diversification, and interacting protein partners. Also, a mechanistic insight on GRAS protein-mediated plant growth and abiotic stress response is provided. For this, we assessed the transcriptional dynamics of GRAS genes in rice (monocot) and Arabidopsis (dicot) at different developmental stages and under several abiotic stresses. Lastly, the usage of genome-editing tools such as the CRISPR/Cas9 system to understand GRAS molecular functions is highlighted, with the ultimate goal of developing improved agronomic and climate-resilient traits in plants.