Background: Abscisic acid-, stress-, and ripening-induced (ASR) genes are a class of plant specific transcription factors (TFs), which play important roles in plant development, growth and abiotic stress responses. The wheat ASRs have not been described in genome-wide yet. Methods: We predicted the transmembrane regions and subcellular localization using the TMHMM server, and Plant-mPLoc server and CELLO v2.5, respectively. Then the phylogeny tree was built by MEGA7. The exon–intron structures, conserved motifs and TFs binding sites were analyzed by GSDS, MEME program and PlantRegMap, respectively. Results: In wheat, 33ASR genes were identified through a genome-wide survey and classified into six groups. Phylogenetic analyses revealed that the TaASR proteins in the same group tightly clustered together, compared with those from other species. Duplication analysis indicated that the TaASR gene family has expanded mainly through tandem and segmental duplication events. Similar gene structures and conserved protein motifs of TaASRs in wheat were identified in the same groups. ASR genes contained various TF binding cites associated with the stress responses in the promoter region. Gene expression was generally associated with the expected group-specific expression pattern in five tissues, including grain, leaf, root, spike and stem, indicating the broad conservation of ASR genes function during wheat evolution. The qRT-PCR analysis revealed that several ASRs were up-regulated in response to NaCl and PEG stress. Conclusion: We identified ASR genes in wheat and found that gene duplication events are the main driving force for ASR gene evolution in wheat. The expression of wheat ASR genes was modulated in responses to multiple abiotic stresses, including drought/osmotic and salt stress. The results provided important information for further identifications of the functions of wheat ASR genes and candidate genes for high abiotic stress tolerant wheat breeding.

Low temperature limits the photochemical efficiency of photosystems in wheat plants. To test the effect of salt priming on the photosynthetic electron transport in wheat under low temperature, the germinating seeds of a winter wheat cv. Jimai44 were primed with varying concentrations of NaCl solutions (0, 10, 30, and 50 mM NaCl, indicated by S0, S10, S30, and S50, respectively) for 6 d, and after 11 d of recovery, the seedlings were subsequently exposed to 24-h low-temperature stress (2 °C). Under low temperature, the S30 plants possessed the highest absorption flux per reaction center and higher density of reaction center per cross-section among the treatments. In addition, S30 plants had higher trapped energy flux for reducing Q_A and fraction of Q_A-reducing reaction centers and non-Q_B reducing center than the non-primed plants under low temperature, indicating that S30 plants could maintain the energy balance of photosystems and a relatively higher maximum quantum efficiency of photosystem II under low temperature. In addition, the low temperature-induced MDA accumulation and cell death were alleviated by salt priming in S30 plants. It was suggested that salt priming with an optimal concentration of NaCl solution (30 mM) during seed germination enhanced the photochemical efficiency of photosystems in wheat seedlings, which could be a potential approach to improve cold tolerance in wheat at an early stage.

Ammonium (NH₄⁺) toxicity is ubiquitous in plants. To investigate the underlying mechanisms of this toxicity and bicarbonate (HCO₃⁻)-dependent alleviation, wheat plants were hydroponically cultivated in half-strength Hoagland nutrient solution containing 7.5 mM NO₃⁻ (CK), 7.5 mM NH₄⁺ (SA), or 7.5 mM NH₄⁺ + 3 mM HCO₃⁻ (AC). Transcriptomic analysis revealed that compared to CK, SA treatment at 48 h significantly upregulated the expression of genes encoding fermentation enzymes (pyruvate decarboxylase (PDC), alcohol dehydrogenase (ADH), and lactate dehydrogenase (LDH)) and oxygen consumption enzymes (respiratory burst oxidase homologs, dioxygenases, and alternative oxidases), downregulated the expression of genes encoding oxygen transporters (PIP-type aquaporins, non-symbiotic hemoglobins), and those involved in energy metabolism, including tricarboxylic acid (TCA) cycle enzymes and ATP synthases, but upregulated the glycolytic enzymes in the roots and downregulated the expression of genes involved in the cell cycle and elongation. The physiological assay showed that SA treatment significantly increased PDC, ADH, and LDH activity by 36.69%, 43.66%, and 61.60%, respectively; root ethanol concentration by 62.95%; and lactate efflux by 23.20%, and significantly decreased the concentrations of pyruvate and most TCA cycle intermediates, the complex V activity, ATP content, and ATP/ADP ratio. As a consequence, SA significantly inhibited root growth. AC treatment reversed the changes caused by SA and alleviated the inhibition of root growth. In conclusion, NH₄⁺ treatment alone may cause hypoxic stress in the roots, inhibit energy generation, suppress cell division and elongation, and ultimately inhibit root growth, and adding HCO₃⁻ remarkably alleviates the NH₄⁺-induced inhibitory effects on root growth largely by attenuating the hypoxic stress.

Timely sowing is a crucial cultivation practice for enhancing crop productivity. In Shandong Province, inadequate supporting cultivation techniques are the primary factors limiting the yield and quality improvement of high-quality strong-gluten wheat (Triticum aestivum L.). A promising strategy for achieving synergistic improvements in both yield and quality involves matching the sowing date and density to the specific ecological conditions of each region. To explore this approach, we conducted continuous field experiments at three testing stations—Jining, Dezhou, and Yantai—across the major wheat-growing regions of Shandong Province from 2019 to 2021. Four sowing dates (T1: October 5; T2: October 15; T3: October 25; and T4: November 5) and seven planting densities (ranging from 135 × 10⁴ plants ha⁻¹ to 405 × 10⁴ plants ha⁻¹, denoted as D1–D7) were tested at each location. The results revealed that the wheat yield in each ecological zone initially increased, then decreased as the sowing dates were delayed. In Jining and Dezhou, high grain yields were typically observed at all densities under T3, while Yantai showed optimal yields under T2. Specifically, Jining achieved the highest grain yield of 9326.6 kg ha⁻¹ with 315 × 10⁴ plants ha⁻¹ on October 25 (T3D5), while Dezhou and Yantai reached their maximum yields under 225 × 10⁴ plants ha⁻¹ on October 15 (T2D3), with yields of 8784.0 kg ha⁻¹ and 9366.3 kg ha⁻¹, respectively. Except in Dezhou, the wheat quality compliance rate at all sites followed an increasing trend initially, which then declined with later sowing dates. In Jining and Yantai, high-quality compliance rates were most frequently achieved under T2, while Dezhou showed optimal quality rates under T1. In conclusion, selecting appropriate sowing dates and densities can lead to synergistic improvements in both grain yield and quality of strong-gluten wheat across Shandong’s wheat-growing regions.

Grain yield establishment is a complex progress and the genetic basis of one of the most important yield components, 100-kernel weight, remains largely unknown. Here, we employed a double haploid (DH) population containing 477 lines which was developed from a cross of two maize elite inbred lines, PHBA6 and Chang7-2, to identify quantitative trait loci (QTL) that related to 100-kernel weight. The phenotypes of the DH population were acquired over three years in two different locations, while the DH lines were genotyped by next-generation sequencing technology of massively parallel 3ʹ end RNA sequencing (MP3RNA-seq). Eventually, 28,874 SNPs from 436 DH lines were preserved after SNP calling and filtering and a genetic map with a length of 837 cM was constructed. Then, single environment QTL analysis was performed using the R/qtl program, and it was found that a total of 17 QTLs related to 100-kernel weight were identified and distributed across the whole genome except chromosomes 5 and 6. The total phenotypic variation explained by QTLs detected in three different environments (BJ2016, BJ2107, and HN2018) was 22.2%, 32.9%, and 51.38%, respectively. Among these QTLs, three of them were identified across different environments as environmentally stable QTLs and explained more than 10% of the phenotypic variance each. Together, the results provided in this study preliminarily revealed the genetic basis of 100-kernel weight and will enhance molecular breeding for key agronomic kernel-related traits in maize.