ZmTCP14, a TCP transcription factor, modulates drought stress response in Zea mays L

Maize (Zea mays L.) is an important food crop and a source of high-quality feed and essential industrial raw materials. Drought, as one of the factors inhibiting plant growth, seriously impacts agricultural production and ecological construction. TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATING CELL FACTOR (TCP) is a family of plant-specific transcription factors that contain the bHLH domain and can regulate plant cell development and abiotic stress. In this study, a TCP transcription factor gene, ZmTCP14, was identified from maize. The results of fluorescence quantitative PCR, enzyme-linked adsorption method, and GUS histochemical staining showed that the ZmTCP14 gene might play a negative feedback role in regulating plant response to drought stress. Furthermore, subcellular localization showed that the gene was localized in the nucleus. ZmTCP14 transgenic maize plants were used to further study its role in drought stress response. Under drought stress, overexpression of the ZmTCP14 gene inhibited seed germination and root growth, and the plants appeared wilted, and the drought resistance was significantly reduced. Interestingly, we also found that introducing the ZmTCP14 gene positively regulated the accumulation of ROS in plants to reduce drought resistance under drought stress. Importantly, under drought conditions in the field, the ZmTCP14 gene-edited plants exhibited higher drought tolerance during the reproductive phase of growth and higher grain yield than the overexpressed plants and non-transgenic controls. All results indicate that ZmTCP14 may affect drought resistance of plants by regulating ROS accumulation in plants.