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AP2/ERF (APETALA2/ethylene responsive factor) is a family of plant-specific transcription factors whose members are widely involved in many biological processes, such as growth, development, and biotic and abiotic stress responses. Here, 20 AP2/ERF genes were identified based on wheat RNA-seq data before and after drought stress, and classified as AP2, ERF, DREB, and RAV. The analysis of gene structure revealed that about 85% of AP2/ERF family members had lost introns, which are presumed to have been lost during the formation and evolution of the wheat genome. The expression of 20 AP2/ERF family genes could be verified by qRT-PCR, which further supported the validity of the RNA-seq data. Subsequently, subcellular localization and transcriptional activity experiments showed that the ERF proteins were mainly located in the nucleus and were self-activating, which further supports their functions as transcription factors. Furthermore, we isolated a novel ERF gene induced by drought, salt, and cold stresses and named it TaERF-6-3A. TaERF-6-3A overexpression increased sensitivity to drought and salt stresses in Arabidopsis, which was supported by physiological and biochemical indices. Moreover, the expression of stress- and antioxidant-related genes was downregulated in TaERF-6-3A-overexpressing plants. Overall, these results contribute to the further understanding of the TaERF-6-3A gene function in wheat. [ABSTRACT FROM AUTHOR]

The WRKY transcription factor family has been associated with a variety of plant biological processes, such as biotic and abiotic stress responses. In this study, 13 wheat TaWRKY DEGs in transcriptome data before and after drought stress, namely TaWRKY1 to TaWRKY8 , including various copies, were identified and classified as Group I, II, or III. TaWRKY1-2D overexpression enhanced drought tolerance in transgenic Arabidopsis. Moreover, the AtRD29A , AtP5CS1 , AtPOD1 , AtCAT1 , and AtSOD (Cu/Zn) genes, which are related to the stress response and antioxidant system, were significantly upregulated in TaWRKY1-2D transgenic Arabidopsis under drought stress. TaWRKY1-2 silencing in wheat increases the MDA content, reduces the contents of proline and chlorophyll and the activities of antioxidant enzymes, and inhibits the expression levels of antioxidant (TaPOD , TaCAT , and TaSOD (Fe))- and stress-related genes (TaP5CS) under drought stress. Yeast two-hybrid screening revealed TaDHN3 as an interaction partner of TaWRKY1-2D; their interaction was further confirmed using yeast two-hybrid and bimolecular fluorescence complementation. Furthermore, TaWRKY1-2D may play essential roles in wheat drought tolerance through posttranslational regulation of TaDHN3. Overall, these findings contribute to our knowledge of the WRKY family in wheat and identify TaWRKY1-2D as a promising candidate gene for improving wheat breeding to generate drought-tolerant wheat. [ABSTRACT FROM AUTHOR]

Drought stress strongly restricts the growth, development, and yield of wheat worldwide. Among the various transcription factors (TFs) involved in the wheat drought response, the specific functions of many basic leucine zipper (bZIP) TFs related to drought tolerance are still not well understood. In this study, we focused on the bZIP TF TabZIP156 in wheat. Our analysis showed that TabZIP156 was highly expressed in both roots and leaves, and it responded to drought and abscisic acid (ABA) stress. Through subcellular localization and transactivation assays, we confirmed that TabZIP156 was located to the nucleus and functioned as a transcriptional activator. Overexpression of TabZIP156 in Arabidopsis enhanced drought tolerance, as evidenced by higher germination rate, longer root length, lower water loss rate, reduced ion leakage, increased proline accumulation, decreased levels of H 2 O 2 , O2− and MDA, and improved activities of POD, SOD, and CAT enzymes. Additionally, the expression of drought- and antioxidant-related genes were significantly upregulated in TabZIP156 transgenic Arabidopsis under drought stress. However, silencing TabZIP156 in wheat led to decreased proline content, increased accumulation of H 2 O 2 , O2− and MDA, reduced activities of antioxidant enzymes, and downregulation of many drought- and antioxidant-related genes under drought stress. Furthermore, the dual-luciferase assay demonstrated that TabZIP156 could activate the expression of TaP5CS , TaDREB1A , and TaPOD by binding to their promoters. Taken together, this study highlights the significant role of TabZIP156 in drought stress and provides valuable insights for its potential application in breeding drought-resistant wheat. • TabZIP156 was significantly induced by drought and abscisic acid treatments. • TabZIP156 was located to the nucleus and functioned as a transcriptional activator. • Overexpression of TabZIP156 enhanced drought tolerance in Arabidopsis. • Silencing of TaZIP156 reduced drought tolerance in wheat. • TabZIP156 could directly bind and activate the expression of TaP5CS, TaDREB1A, and TaPOD. [ABSTRACT FROM AUTHOR]