MaDREB1F confers cold and drought stress resistance through common regulation of hormone synthesis and protectant metabolite contents in banana

Abstract

Adverse environmental factors severely affect crop productivity. Improving crop resistance to multiple stressors is an important breeding goal. Although <i>CBF</i>s<i>/DREB1</i>s extensively participate in plant resistance to abiotic stress, the common mechanism underlying <i>CBFs/DREB1</i>s that mediate resistance to multiple stressors remains unclear. Here, we show the common mechanism for <i>MaDREB1F</i> conferring cold and drought stress resistance in banana. <i>MaDREB1F</i> encodes a dehydration-responsive element binding protein (DREB) transcription factor with nuclear localization and transcriptional activity. <i>MaDREB1F</i> expression is significantly induced after cold, osmotic, and salt treatments. <i>MaDREB1F</i> overexpression increases banana resistance to cold and drought stress by common modulation of the protectant metabolite levels of soluble sugar and proline, activating the antioxidant system, and promoting jasmonate and ethylene syntheses. Transcriptomic analysis shows that MaDREB1F activates or alleviates the repression of jasmonate and ethylene biosynthetic genes under cold and drought conditions. Moreover, MaDREB1F directly activates the promoter activities of <i>MaAOC4</i> and <i>MaACO20</i> for jasmonate and ethylene syntheses, respectively, under cold and drought conditions. MaDREB1F also targets the <i>MaERF11</i> promoter to activate <i>MaACO20</i> expression for ethylene synthesis under drought stress. Together, our findings offer new insight into the common mechanism underlying <i>CBF/DREB1</i>-mediated cold and drought stress resistance, which has substantial implications for engineering cold- and drought-tolerant crops.