Glycine max DREB1D transcription factor regulates plant height by reducing gibberellin levels and response.

Overexpression of GmDREB1D reduces plant height of soybean. Overexpression of GmDREB1D reduced active GA content and GmDREB1D can regulate GmGA2ox8. GmDREB1D may inhibit growth by reducing the levels of active GAs and response. Dehydration responsive element binding (DREB) proteins play an important role in growth and abiotic stress. Although the DREB1D transcription factor contributes to drought tolerance, the molecular mechanisms underlying growth inhibition are unclear. In this study, we reveal the function of GmDREB1D as a transcriptional regulator in growth. Overexpression of GmDREB1D reduces plant height and leaf area of soybeans. Endogenous bioactive gibberellins (GAs) levels are reduced in GmDREB1Dox plants. Transcriptome sequencing (RNA-seq), DNA affinity sequencing (DAP-seq), Dual-luciferase assay (Dual-Luc), and Electrophoretic Mobility Shift Assay (EMSA) results indicate that GmDREB1D activates the expression of GmGA2ox8. Exogenous gibberellin GA3 rescued the typical GA deficiency phenotypes exhibiting dwarfism. Compared with the wild type, soybean plants overexpressing GmDREB1D showed a reduced response to gibberellin under high concentration GA3 treatment. GmDREB1D forms the core of a potential regulatory module that triggers the inactivation of GAs and reduces GA response to limit plant height.