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.

Flowering time is one of the most important agronomic traits in wheat production. A proper flowering time might contribute to the reduction or avoidance of biotic and abiotic stresses, adjust plant architecture, and affect the yield and quality of grain. In this study, TaTOE1-B1 in wheat produced three transcripts (TaTOE1-B1-1, TaTOE1-B1-2, and TaTOE1-B1-3) by alternative splicing. Compared to the longest transcript, TaTOE1-B1-1, TaTOE1-B1-3 has a deletion in the sixth exon (1219–1264 bp). Under long-day conditions, the heterologous overexpression of the TaTOE1-B1-3 gene delayed flowering, prolonged the vegetative growth time, and enlarged the vegetative body of Arabidopsis, but that of TaTOE1-B1-1 did not. As typical AP2 family members, TaTOE1-B1-1 and TaTOE1-B1-3 are mainly located in the nucleus and have transcriptional activation activities; the transcriptional activation region of TaTOE1-B1-3 is located in the C-terminal. In TaTOE1-B1-3 overexpression lines, the expression of flowering-related AtFT and AtSOC1 genes is significantly downregulated. In addition, this study confirms the protein–protein interaction between TaTOE1-B1-3 and TaPIFI, which may play an important role in flowering inhibition. These results provide a theoretical basis for the precise regulation of wheat flowering time.

Miscanthus, a perennial grass, is renowned for its remarkable tolerance to abiotic stress. Excessive levels of drought severely impair plant growth and yield. Plant nuclear factor Y (NF-Y) transcription factors (TFs) play pivotal roles in regulating responses to drought stress in species such as Arabidopsis and maize. However, their functional roles in conferring drought tolerance in Miscanthus remain largely unexplored. This study’s genome-wide analysis and gene expression profiling of Miscanthus under dehydration/osmotic stress identified a transcription factors gene, MsNF-YA4, which was significantly upregulated under dehydration/osmotic stress. MsNF-YA4 overexpression in Arabidopsis significantly enhanced drought tolerance, leading to increased transcription of stress- and antioxidant enzyme-related genes. Compared with the wild type (WT), the transgenic lines exhibited markedly higher relative water content (RWC), chlorophyll content, proline level, and antioxidant enzyme activity. Furthermore, the MsNF-YA4/MsNF-YB3/MsNF-YC2 improved the transactivation of the Miscanthus P5CS1, SOD (Cu/Zn) and CAT1 promoters in the transient system. These results offer fresh perspectives on the role of Miscanthus NF-YAs in drought tolerance and offer promising genetic resources for developing drought-tolerant crops through breeding programs.