The soybean PLATZ transcription factor GmPLATZ17 suppresses drought tolerance by interfering with stress-associated gene regulation of GmDREB5

Plant AT-rich sequence and zinc binding (PLATZ) transcription factors are a class of plant specific zinc-dependent DNA-binding proteins that function in abiotic stress response and plant development. In this study, 31 GmPLATZ genes were identified in soybean. GmPLATZ17 was down-regulated by drought and exogenous abscisic acid. Transgenic Arabidopsis and soybean hairy roots overexpressing GmPLATZ17 showed drought sensitivity and inhibition of stress-associated gene transcription. In contrast, suppressed expression of GmPLATZ17 led to increased drought tolerance in transgenic soybean hairy roots. The GmPLATZ17 protein was verified to interact physically with the GmDREB5 transcription factor, and overexpression of GmDREB5 increased drought tolerance in soybean hairy roots. Interaction of GmPLATZ17 with GmDREB5 was shown to interfere with the DRE-binding activity of GmDREB5, suppressing downstream stress-associated gene expression. These results show that GmPLATZ17 inhibits drought tolerance by interacting with GmDREB5. This study sheds light on PLATZ transcription factors and the function of GmPLATZ17 in regulating drought sensitivity.