Members of the abscisic acid (ABA)-responsive element (ABRE) binding factor (ABF) and ABA-responsive element binding protein (AREB) families play essential roles in the regulation of ABA signaling pathway activity and shape the ability of plants to adapt to a range of stressful environmental conditions. To date, however, systematic genome-wide analyses focused on the ABF/AREB gene family in wheat are lacking. Here, we identified 35 ABF/AREB genes in the wheat genome, designated TaABF1–TaABF35 according to their chromosomal distribution. These genes were further classified, based on their phylogenetic relationships, into three groups (A–C), with the TaABF genes in a given group exhibiting similar motifs and similar numbers of introns/exons. Cis-element analyses of the promoter regions upstream of these TaABFs revealed large numbers of ABREs, with the other predominant elements that were identified differing across these three groups. Patterns of TaABF gene expansion were primarily characterized by allopolyploidization and fragment duplication, with purifying selection having played a significant role in the evolution of this gene family. Further expression profiling indicated that the majority of the TaABF genes from groups A and B were highly expressed in various tissues and upregulated following abiotic stress exposure such as drought, low temperature, low nitrogen, etc., while some of the TaABF genes in group C were specifically expressed in grain tissues. Regulatory network analyses revealed that four of the group A TaABFs (TaABF2, TaABF7, TaABF13, and TaABF19) were centrally located in protein–protein interaction networks, with 13 of these TaABF genes being regulated by 11 known miRNAs, which play important roles in abiotic stress resistance such as drought and salt stress. The two primary upstream transcription factor types found to regulate TaABF gene expression were BBR/BPC and ERF, which have previously been reported to be important in the context of plant abiotic stress responses. Together, these results offer insight into the role that the ABF/AREB genes play in the responses of wheat to abiotic stressors, providing a robust foundation for future functional studies of these genes.

Transcription factors (TFs) are important regulators of numerous gene expressions due to their ability to recognize and combine cis-elements in the promoters of target genes. The INDETERMINATE DOMAIN (IDD) gene family belongs to a subfamily of C2H2 zinc finger proteins and has been identified only in terrestrial plants. Nevertheless, little study has been reported concerning the genome-wide analysis of the IDD gene family in maize. In total, 22 ZmIDD genes were identified, which can be distributed on 8 chromosomes in maize. On the basis of evolutionary relationships and conserved motif analysis, ZmIDDs were categorized into three clades (1, 2, and 3), each owning 4, 6, and 12 genes, respectively. We analyzed the characteristics of gene structure and found that 3 of the 22 ZmIDD genes do not contain an intron. Cis-element analysis of the ZmIDD promoter showed that most ZmIDD genes possessed at least one ABRE or MBS cis-element, and some ZmIDD genes owned the AuxRR-core, TCA-element, TC-rich repeats, and LTR cis-element. The Ka:Ks ratio of eight segmentally duplicated gene pairs demonstrated that the ZmIDD gene families had undergone a purifying selection. Then, the transcription levels of ZmIDDs were analyzed, and they showed great differences in diverse tissues as well as abiotic stresses. Furthermore, regulatory networks were constructed through the prediction of ZmIDD-targeted genes and miRNAs, which can inhibit the transcription of ZmIDDs. In total, 6 ZmIDDs and 22 miRNAs were discovered, which can target 180 genes and depress the expression of 9 ZmIDDs, respectively. Taken together, the results give us valuable information for studying the function of ZmIDDs involved in plant development and climate resilience in maize.

Glutaredoxins (GRXs) are small-molecular-weight proteins present in a wide range of organisms, and they play a key role in maintaining the redox homeostasis of cells. Most studies on GRXs are conducted in animals and humans, and those conducted on plants are scarce. The number and types of GRX genes vary in different plants. According to the active sites, the GRX family can be further divided into the CPYC, CGFS, and CC subfamilies. The CPYC and CGFS subfamilies are present in eukaryotes. The CC subfamily is exclusively present in higher plants and has the highest number of genes. In this study, 85 GRX genes were identified in common wheat (Triticum aestivum L.) using a bioinformatic method, wherein 12, 9, and 64 belonged to the CPYC, CGFS, and CC subfamilies, respectively. All TaGRX genes were homogeneously distributed in the three subgenomes of wheat. The gene structure analysis revealed that TaGRX members had 1–7 introns. The conserved motif analysis revealed that members of the same TaGRX subfamily had similar motifs. An analysis of cis-regulatory elements of promoters demonstrated that most TaGRX members had auxin-responsive elements; cis-regulatory elements, such as methyl jasmonate (MeJA), MYB, and abscisic acid (ABA), were distributed in all subfamilies, and the cell-cycle regulation element was only observed in the CC and CPYC subfamily members. Additionally, the synteny of the GRX genes in wheat, in wheat and Arabidopsis, and in wheat and barley was analyzed to clarify the evolutionary correlation of TaGRXs. The expression characteristics of TaGRXs were investigated, and TaGRX expression in various tissues and its responses to different abiotic stresses were preliminarily determined. This study provides a reference for the functional analysis of TaGRXs and understanding their role in molecular breeding of wheat.

Salt tolerance is a critical trait for plant survival and productivity in saline environments. Development of salt tolerant crops is a practical strategy for addressing soil salinity issues. In this study, RNA-Seq analysis was performed using two wheat cultivars with contrasting salt tolerance (Neixiang188, tolerant and Barra, sensitive) at 6 h and 24 h after salinity treatment to determine the genetic variations reflected in the RNA expression patterns and identify key genes associated with salt tolerance. Our results revealed that there were 2983 upregulated and 1091 downregulated differentially expressed genes (DEGs), which were found in common in the two accessions. Meanwhile, 529 salt tolerant associated DEGs were subjected to GO function annotation, KEGG enrichment, and protein–protein interaction (PPI) network prediction. Finally, a theoretical framework outlining the salt tolerance mechanisms of Neixiang188 was proposed. It can be inferred that Neixiang188 possesses superior ion homeostasis, ROS detoxification, and osmotic adjustment abilities compared to Barra when subjected to saline stress. The present research sheds light on the genetic foundation of salt tolerance in wheat and offers candidate genes for genetic manipulation. Our research insights enhance the comprehension of the molecular mechanisms underlying salt stress responses and could guide future breeding efforts for improving salt tolerance in crops.

Double B-box (DBB) proteins are plant-specific transcription factors (TFs) that play crucial roles in plant growth and stress responses. This study investigated the classification, structure, conserved motifs, chromosomal locations, cis-elements, duplication events, expression levels, and protein interaction network of the DBB TF family genes in common wheat (Triticum aestivum L.). In all, twenty-seven wheat DBB genes (TaDBBs) with two conserved B-box domains were identified and classified into six subgroups based on sequence features. A collinearity analysis of the DBB family genes among wheat, Arabidopsis, and rice revealed some duplicated gene pairs and highly conserved genes in wheat. An expression pattern analysis indicated that wheat TaDBBs were involved in plant growth, responses to drought stress, light/dark, and abscisic acid treatment. A large number of cis-acting regulatory elements related to light response are enriched in the predicted promoter regions of 27 TaDBBs. Furthermore, some of TaDBBs can interact with COP1 or HY5 based on the STRING database prediction and yeast two-hybrid (Y2H) assay, indicating the potential key roles of TaDBBs in the light signaling pathway. Conclusively, our study revealed the potential functions and regulatory mechanisms of TaDBBs in plant growth and development under drought stress, light, and abscisic acid.

Tube-like outgrowths from root epidermal cells, known as root hairs, enhance water and nutrient absorption, facilitate microbial interactions, and contribute to plant anchorage by expanding the root surface area. Genetically regulated and strongly influenced by environmental conditions, longer root hairs generally enhance water and nutrient absorption, correlating with increased stress resistance. Wheat, a globally predominant crop pivotal for human nutrition, necessitates the identification of long root hair genotypes and their regulatory genes to enhance nutrient capture and yield potential. This study focused on 261 wheat samples of diverse genotypes during germination, revealing noticeable disparities in the length of the root hair among the genotypes. Notably, two long root hair genotypes (W106 and W136) and two short root hair genotypes (W90 and W100) were identified. Transcriptome sequencing resulted in the development of 12 root cDNA libraries, unveiling 1180 shared differentially expressed genes (DEGs). Further analyses, including GO function annotation, KEGG enrichment, MapMan metabolic pathway analysis, and protein–protein interaction (PPI) network prediction, underscored the upregulation of root hair length regulatory genes in the long root hair genotypes. These included genes are associated with GA and BA hormone signaling pathways, FRS/FRF and bHLH transcription factors, phenylpropanoid, lignin, lignan secondary metabolic pathways, the peroxidase gene for maintaining ROS steady state, and the ankyrin gene with diverse biological functions. This study contributes valuable insights into modulating the length of wheat root hair and identifies candidate genes for the genetic improvement of wheat root traits.