Search

Soil salinization poses a significant challenge to global agriculture, particularly in arid and semi-arid regions like Xinjiang. Kalidium schrenkianum , a halophytic plant adapted to saline-alkaline conditions, harbors endophytic microorganisms with potential plant growth-promoting properties. In this study, 177 endophytic bacterial strains were isolated from K. schrenkianum , and 11 key strains were identified through functional screening based on salt tolerance, nutrient solubilization, and growth-promoting traits. Synthetic microbial communities (SMCs) were then constructed using these strains and optimized to enhance wheat growth under salt stress. The SMCs significantly improved seed germination, root length, and seedling vigor in both spring and winter wheat in hydroponic and pot experiments. Furthermore, the SMCs enhanced the activities of antioxidant enzymes, including superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and levels of malondialdehyde (MDA) and proline (PRO). They also reduced oxidative stress and improved chlorophyll content in wheat seedlings. These results demonstrate the potential of microbial consortia derived from extreme environments as eco-friendly biofertilizers for improving crop performance in saline soils, offering a sustainable alternative to chemical fertilizers and contributing to agricultural resilience and productivity.

This study investigated the effects of various titanium nanoparticles (TiO 2 NPs) on the structure, function, and trophic levels of the wheat rhizobiome. In contrast to the typically toxic effects of small nanoparticles (~10 nm), this research focused on molecular TiO 2 and larger nanoparticles, as follows: medium-sized (68 nm, NPs1) and large (>100 nm, NPs2). The results demonstrated significant yet diverse impacts of different TiO 2 forms on the rhizosphere microbiota. Large TiO 2 NPs2 and molecular TiO 2 adversely affected the bacteriobiome and mycobiome, leading to an increase in autotrophic microbial groups. In contrast, medium-sized TiO 2 NPs1 shifted the microbiome toward chemoheterotrophy, promoting plant growth-associated bacteria, fungal saprotrophs, and potential phytopathogens, suggesting a beneficial r-strategy within the rhizosphere. Other treatments induced oligotrophic conditions, resulting in a less flexible rhizobiome with diminished root associations but an increased abundance of Trichoderma spp. Structural modelling revealed that even minor changes in operational taxonomic units (OTUs) could significantly alter the microbiota's metabolic potential. These findings highlight the importance of further research to optimize nanoparticle applications for sustainable agriculture.

Drought stress severely damages wheat growth and photosynthesis, and plants at the grain-filling stage are the most sensitive to drought throughout the entire period of development. Exogenous spraying of sodium nitroprusside (SNP) can alleviate the damage to wheat caused by drought stress, but the mechanism regulating the proline pathway remains unknown. Two wheat cultivars, drought-sensitive Zhoumai 18 and drought-tolerant Zhengmai 1860, were used as materials when the plants were cultivated to the grain-filling stage. The results show that under drought stress, SNP pretreatment effectively improved the physiological basis of photosynthesis and water use efficiency of the two cultivars, increased their tolerance to photosystem II (PSII) damage, and maintained a normal photosynthetic rate and yield. Drought stress induced an increase in pyrroline-5-carboxylate synthase ( TaP5CS ) gene transcription, and a comparatively greater increase was detected in Zhengmai 1860. When SNP treatment was applied before drought exposure, TaP5CS transcription was further enhanced. Induction of TaP5CS transcription promoted proline accumulation in response to drought stress, increased osmotic ability, and maintained the net photosynthetic rate, thereby increasing the accumulation of dry matter and yield traits. In this study, exogenous SNP regulates the transcription of genes related to the proline metabolism pathway and provides a theoretical basis for the establishment of wheat cultivation technology using SNP to resist drought stress.

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.

Wheat is one of the most extensively grown crops in the world; however, its productivity is reduced due to salinity. This study focused on millimeter wave (MMW) irradiation to clarify the salt-stress tolerance mechanism in wheat. In the present study, wheat-root growth, which was suppressed to 77.6% of the control level under salt stress, was recovered to the control level by MMW irradiation. To reveal the salt-stress tolerance mechanism of MMW irradiation on wheat, a proteomic analysis was conducted. Proteins related to cell cycle, proliferation, and transport in biological processes, as well as proteins related to the nucleus, cytoskeleton, and cytoplasm within cellular components, were inversely correlated with the number of proteins. The results of the proteomic analysis were verified by immunoblot and other analyses. Among the proteins related to the scavenging reactive-oxygen species, superoxide dismutase and glutathione reductase accumulated under salt stress and further increased in the MMW-irradiated wheat. Among pathogen-related proteins, pathogenesis-related protein 1 and the Bowman-Birk proteinase inhibitor decreased under salt stress and recovered to the control level in the MMW-irradiated wheat. The present results indicate that MMW irradiation of wheat seeds improves plant-growth recovery from salt stress through regulating the reactive oxygen species-scavenging system and the pathogen-related proteins. These genes may contribute to the development of salt-stress-tolerant wheat through marker-assisted breeding and genome editing., Competing Interests: The authors declare no conflicts of interest.

There is growing interest in low-temperature food processing. In the baking industry, low-temperature fermentation improves the production of natural aroma compounds, which have a positive impact on the sensory profile of the final product. The aim of this study was to develop a yeast-lactic acid bacteria starter culture that effectively ferments wheat dough at a temperature of 15 °C. The microorganisms were selected based on their enzymatic activity and ability to grow at low temperature. The fermentation activity of the yeast and mixed cultures was assessed enzymatically. The biosynthesis of volatile organic compounds was quantified using the HS-GC-MS technique. Samples fermented by S. cerevisiae D3 were characterized by the highest concentration of volatile organic compounds, especially esters. The addition of lactic acid bacteria increased not only the biosynthesis of volatile organic compounds but also the productivity of carbon dioxide during dough fermentation. Based on both dough expansion and the profile of volatile organic compounds, a mixed culture of S. cerevisiae D3 and L. brevis B46 was selected as the most effective starter for low-temperature fermentation.

The NF-YA gene family is a highly conserved transcription factor that plays a crucial role in regulating plant growth, development, and responses to various stresses. Despite extensive studies in multiple plants, there has been a dearth of focused and systematic analysis on NF-YA genes in wheat grains. In this study, we carried out a comprehensive bioinformatics analysis of the NF-YA gene family in wheat, using the latest genomic data from the Chinese Spring. A total of 19 TaNF-YA genes were identified. An analysis of conserved domains, phylogenetic relationships, and gene structure indicated a significant degree of conservation among TaNF-YAs. A gene collinearity analysis demonstrated that fragment duplication was the predominant mechanism driving the amplification of TaNF-YAs . Furthermore, cis -acting elements within the promoters of TaNF-YAs were found to be implicated in grain development. Subsequently, SNP analysis revealed the genetic variation in the NF-YA gene family in different wheat. Moreover, published RNA-seq data were used and RNA-seqs of Pinyu8155, Yaomai30, Yaomai36, and Pinyu8175 were performed to identify TaNF-YAs influencing grain development. Finally, it was found that NF-YAs had no self-activating activity in wheat. This study provides key candidate genes for the exploration of grain development in the wheat filling stage and also lays a foundation for further research on the regulation of starch and protein synthesis and accumulation.

Soil salinity is considered a serious problem that limits agricultural productivity. Currently, solutions are being sought to mitigate the negative impact of salt on economically important crops. The aim of the study was to evaluate the effect of foliar application of silicon (Si) on the physiological and epigenetic responses of wheat grown under salt stress conditions. The experiment with wheat seedlings was established in pots with 200 mM NaCl added. After 7 days, foliar fertilizer (200 g L -1 SiO 2 ) was used at concentrations of 0.05, 0.1 and 0.2%. Physiological parameters were measured three times. The addition of salt caused a significant decrease in the values of the measured parameters in plants of all variants. In plants sprayed with Si fertilizer under salinity conditions, a significant increase in CCI and selected gas exchange parameters ( P N , C i , E , g s ) and chlorophyll fluorescence (PI, RC/ABS, F V /F m , Fv/F 0 ) was observed. Si doses of 0.1 and 0.2% showed a better mitigating effect compared to the dose of 0.05%. The observed effect was maintained over time. The results obtained indicate a positive role for foliar silicon fertilization in mitigating salinity stress in wheat. Epigenetic mechanisms play an important role in regulating gene expression in response to stress. Changes in the status of methylation of the 5'CCGG3' sequence of the nuclear genome of wheat plants exposed to salinity and treated with Si at different doses were determined by the MSAP approach. The obtained results showed a clear alteration of DNA methylation in plants as a response to experimental factors. The methylation changes were silicon dose-dependent. These modifications may suggest a mechanism for plant adaptation under salt stress after silicon application.

Waxy cuticle covers plant aerial organs and protects plants against environmental challenges. Although improved cuticle-associated traits are aimed at the wheat breeding programs, the mechanism governing wheat cuticular wax biosynthesis remains to be elucidated. Herein, wheat WW domain-containing protein TaCFL1 is characterized as a negative regulator of wax biosynthesis. The knockdown of TaCFL1 expression results in a 15% increase in wax accumulation and decreased leaf cuticle permeability in bread wheat. Furthermore, wheat class IV homeodomain transcription factors TaHDG1.1 and TaHDG1.2 are identified as partially redundant activators of wax biosynthesis. The silencing of TaHDG1.1 or TaHDG1.2 expression leads to an 11% reduction in epidermal wax accumulation and an increase in leaf cuticle permeability wax, while the co-silencing of TaHDG1.1 and TaHDG1.2 results in a 31% reduction in epidermal wax accumulation and a further increase in wax in the leaf cuticle permeability. Moreover, wheat 3-Ketoacyl-CoA synthase TaKCS10 is isolated as an essential component of the wax biosynthetic machinery. The silencing of TaKCS10 expression results in a 22% reduction in wax accumulation and increased leaf cuticle permeability. In addition, we demonstrated that the TaKCS10 expression is activated by TaHDG1.1 and TaHDG1.2, and that TaCFL1 attenuates the TaHDG1-mediated transcriptional activation of TaKCS10 . This evidence supports that the WW domain-containing protein TaCFL1 negatively regulates wax biosynthesis via attenuating the transcriptional activation of the TaKCS10 gene mediated by HD-ZIP IV transcription factor TaHDG1.

Soil salinity adversely affects plant growth and development, reducing the yield of most crops, including wheat. The highly salt-tolerant wheat germplasm lines W4909 and W4910 were derived from a cross between two moderately salt-tolerant lines, the Chinese Spring (CS)/ Thinopyrum junceum disomic addition line AJDAj5 (AJ) and the Ph-inhibitor line (Ph-I) derived from CS/ Aegilops speltoides . Molecular markers for gene introgressions in W4909 and W4910 were not reported. Four sequence-tagged site (STS) molecular markers of Ph-I were developed and tested in the above-mentioned lines and the F 2 progenies of the two crosses, Anza (AZ) × 4740 (sib of W4910) and Yecora Rojo (YR) × 4728 (sib of W4909). Additionally, homogeneity was assessed in several derivatives of W4909, 4728, W4910, and 4740 using the four markers. The four STS markers are not associated with salt tolerance, but they provide an indication of the transfer of chromatin in 3 B chromosome of Ae. speltoides via Ph-I. Moreover, salt tolerance and leaf sodium concentration were determined in CS, AJ, Ph-I, 7151 (progeny of W4909), 7157 (progeny of W4910), AZ, and YR under salt treatment and control. Surprisingly, AJ had the lowest leaf sodium concentration under the control and salt treatment, indicating greater sodium exclusion than that in CS, AZ, and YR. This low level of leaf sodium concentration was heritable from 4740 to its hybrid progenies. On the other hand, the higher leaf sodium concentration, indicative of the tissue tolerance to salinity in Ph-I, had been inherited by both W4909 and W4910 and then transmitted to their hybrid progenies. One offspring line each in both W4909 and W4910 (7762 and 7159, respectively) were homozygous for the three molecular markers and lacked the marker psr1205 of Su1-Ph1 gene, making them better materials than the original lines for future research on, for example, whole-genome sequencing and gene mining. The implications of these findings for the utilization of W4909 and W4910 in breeding salt-tolerant wheat cultivars are discussed.

Background: Sulfur (S) is a vital element for the normal growth and development of plants, performing crucial biological functions in various life processes., Methods: This study investigated thirteen S utilization efficiency (SUE)-related traits at the seedling stage of wheat using a recombinant inbred line (RIL) population. The quantitative trait loci (QTLs) were mapped by genetic mapping. Thirteen S utilization efficiency-related traits were investigated under two hydroponic culture trials with low S (0.1S, T1), moderate S (0.5S, T2), and high S (1.5S, T3) levels, using the wheat RILs., Results: A total of 170 QTLs for the thirteen traits in different treatment environments were identified. Among them, 89, 103, and 101 QTLs were found in T1, T2, and T3, respectively. A total of 63 QTLs were found in the multiple treatment environments, the other 107 QTLs only being detected in a single treatment environment. Among them, thirteen relatively high-frequency QTLs (RHF-QTLs) and eleven QTL clusters were found. Five ( QSh-1D , QRn-1D , QSdw-1D , QTdw-1D , and QTsc-1D ) and six ( QRdw-6A , QSdw-6A , QTdw-6A , QRsc-6A , QSsc-6A , and QTsc-6A ) RHF-QTLs were identified in QTL clusters C3 and C10, respectively., Conclusion: These thirteen RHF-QTLs and eleven QTL clusters are expected to apply to the molecular marker-assisted selection (MAS) of wheat.

The plant peptide-containing sulfated tyrosine (PSY) family plays critical roles in plant cell proliferation and stress responses. However, the functional characterization of the PSY peptide family in wheat remains unclear. This study systematically identified a total of 29 TaPSY genes at the genome-wide level, classifying them into six subgroups based on PSY-like motifs. These peptides contain a highly conserved active peptide domain, closely resembling the Arabidopsis AtPSY1 motif. All TaPSY homologs are predicted to have a sulfated tyrosine catalyzed by plant tyrosylprotein sulfotransferase (TPST). The TaPSY genes displayed distinct expression patterns across various tissues, with most genes showing higher expression levels in roots and stems. Synthetic sulfated TaPSY peptides enhanced root growth in both wild-type Arabidopsis and the tpst-1 mutant plants. In wheat, exogenous application of TaPSY peptides also promoted root growth, with the synthetic TaPSY5 peptide affecting reactive oxygen species levels in wheat taproots to stimulate primary root growth. Furthermore, transgenic Arabidopsis plants overexpressing TaPSY10 exhibited longer primary roots and increased lateral root numbers. These findings provide insights into the physiological roles of TaPSY peptides in regulating wheat root growth., Competing Interests: The authors declare no conflicts of interest.

Brassinazole-resistant (BZR) transcription factors are important transcription factors in Brassinosteroid (BR)-responsive gene expression. However, limited knowledge exists regarding the BZR genes in wheat and a limited number of BZR family genes have been previously reported in wheat. In this study, the synteny analyses of the TaBZR genes suggested that gene duplication events have played an essential role in the TaBZR family during evolution. The results of RT-qPCR and transcriptome data analyses exhibited remarkable expression patterns in the BZR genes in different tissues and under different treatments. The yeast two-hybrid (Y2H) screen result showed that the TaBZR2.1 protein interacts with Argonaute 4 (AGO4). Taken together, our results not only provide us a basis for understanding the molecular characteristics and expression patterns of the TaBZR family genes but also offered the functional characterization of TaBZR2.1 in wheat.

Amino acids are the main form of nitrogen in plants, and their transport across cell membranes relies on amino acid transporters (AATs). Among the plant AATs, the TaATLa subfamily comprises 18 members, yet the bioinformatics characteristics and functions of TaATLa genes in common wheat remain poorly understood due to their complex genomes. This study performed genomic analyses of TaATLas . These analyses included chromosome distributions, evolutionary relationships, collinearity, gene structures, and expression patterns. An analysis of cis-acting elements and predicted miRNA- TaATLas regulatory networks suggests that TaATLas are regulated by light, hormones, and stress signals. Functional assays revealed that TaATLa6 transports glutamine (Gln), glutamate (Glu), and aspartate (Asp) in yeast. In contrast, TaATLa4 specifically transports Gln and Asp. Furthermore, TaATLas exhibits diverse gene expression patterns, with TaATLa4-7D enhancing yeast heat tolerance in a heterologous expression system, indicating its potential role in adapting to environmental stress by regulating amino acid transport and distribution. This study sheds light on the functional roles of TaATLa genes, with implications for improving nitrogen use in wheat and other crop species.

High-temperature (HT) stress frequently affects the early and middle stages of grain filling in hybrid seed production regions. Photo-thermo-sensitive male-sterile (PTMS) wheat lines, which play a critical role as female parents in hybrid seed production, face challenges under HT conditions. However, the mechanisms governing grain filling in PTMS lines under HT stress remain poorly understood. This study used the BS253 line to investigate the effects of HT on grain filling, primarily focusing on the transition from sucrose unloading to starch synthesis. The findings indicated that HT significantly reduced the grain starch content and weight by 7.65% and 36.35% at maturity, respectively. Further analysis revealed that the expression levels of TaSUT1 and TaSWEETs in grains initially increased after HT stress, paralleling the rise in sucrose content during the same period. The activities of ADP-glucose pyrophosphorylase, UDP-glucose pyrophosphorylase, granule-bound starch synthase, and soluble starch synthase were markedly decreased, indicating that impaired starch synthesis was a key factor limiting grain filling immediately after HT exposure. A total of 41 key regulatory genes involved in sucrose-to-starch metabolism were identified, with HT significantly reducing the expression of genes associated with pathways from sucrose unloading to starch synthesis during the middle and late stages post-HT. Based on the observed ultrastructural changes in the abdominal phloem and sucrose transporter expression levels under HT, we concluded that limited sucrose supply, degradation, and inhibition of starch synthesis collectively constrained grain filling during these stages. Additionally, 11 heat shock proteins and two catalase genes were identified and significantly upregulated during the initial phase post-HT, suggesting their potential role in enhancing sucrose supply at this critical time. More importantly, seven key genes involved in the sucrose-to-starch pathway were identified by weighted gene co-expression network analysis ( WGCNA ), which provides target genes for their functional research for starch synthase. These findings provide a comprehensive understanding of how HT limits grain filling, identify several genes involved in the sucrose-to-starch pathway, and offer a novel perspective for future research on HT-restricted grain filling across the entire process from sucrose unloading to starch synthesis in developing grains.

Extensive utilization of renewable biomass is crucial for the progress of carbon neutral and carbon peak implementation. Wheat straw, as an important by-product of crops, is hardly ever efficiently utilized by conventional processes. Here, we proposed a mild acid-coupled-with-enzymatic-treatment process to realize the utilization of lignin and hemicelluloses from pulping liquor on the basis of the chemical-mechanical pulping process. The pulping liquor was treated with acid first to precipitate lignin, and it was further hydrolyzed with xylanase to obtain XOSs. The recovered lignin was characterized by FT-IR, 2D-HSQC, GPC, etc. It was found that lignin undergoes depolymerization and condensation during acid treatment. Also, saccharide loss enhanced with the decrease in pH due to the presence of the LCC structure. As a result, an optimized pH of 4 for the acid treatment ensured that the removal rate of lignin and loss rate of polysaccharides achieved 77.15% and 6.13%, respectively. Moreover, further xylanase treatment of the pulping liquor attained a recovery rate of 51.87% for XOSs. The study presents a new insight for the efficient utilization of lignin and hemicellulose products from non-woody materials in the prevailing biorefinery concept.

Wheat can tolerate a mild water deficit, but prolonged drought causes a number of detrimental physiological changes resulting in a substantial decrease in productivity. The present study evaluates the potential of the natural plant growth regulator melatonin to alleviate the negative effects of moderate drought in two Bulgarian winter wheat cultivars at the early vegetative stage. Melatonin doses of 75 µM were root-supplemented 24 h before or after the stress period. The levels of several biometric parameters, osmolyte content and stress indicators as well as the expression of genes coding for key enzymes of the proline biosynthesis pathway were analyzed in leaves at the end of the drought stress and after two and four days of recovery. Applied alone, melatonin did not exert significant effects on most of the monitored parameters. Water deprivation negatively affected seedlings' fresh weight and water content and increased the stress markers and osmolyte levels. These were accompanied by a high accumulation of TaP5CS and TaP5CR transcripts coding for the enzymes Δ-pyrroline-5-carboxylate synthase and Δ-pyrroline-5-carboxylate reductase, respectively. The effect of melatonin in reducing drought stress was similar whether applied before or after exposure, though slightly more effective when used as a pre-treatment.

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 ( TaDBB s) 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 TaDBB s 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 TaDBB s. 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 TaDBB s in the light signaling pathway. Conclusively, our study revealed the potential functions and regulatory mechanisms of TaDBB s in plant growth and development under drought stress, light, and abscisic acid.

The low-temperature stress (LTS) in spring results in tremendous yield loss in wheat production, and the application of potassium dihydrogen phosphate (KH 2 PO 4 ) can alleviate stress-induced damage. However, the underlying effect of spraying KH 2 PO 4 on the physiological characteristics of wheat flag leaves under spring LTS remains unclear. In this study, we investigated the effect of spraying KH 2 PO 4 on flag leaf physiological traits and yield under spring LTS, including treatments at 15 °C and spraying H 2 O (CK), treatment at -4 °C and spraying H 2 O (LT1), and treatment at -4 °C and spraying KH 2 PO 4 (LT2). The results showed that spraying KH 2 PO 4 significantly increased the activities of the superoxide dismutase (SOD), the peroxidase (POD), and the catalase (CAT), and reduced malondialdehyde (MDA) content in the flag leaves. Compared to LT1, the SOD, POD, and CAT activities in the flag leaves of the Yangnong19 (YN19) and Xinmai26 (XM26) via LT2 increased by 5.5%, 10.9%, and 3.9%, and 5.4%, 9.2%, and 4.4%, respectively, and the MDA content of the YN19 and XM26 decreased by 10.5% and 9.1%, respectively, at 0-12 d after low temperature treatment (DALTT). Spraying KH 2 PO 4 appreciably alleviated damage to the leaf cell morphology and tissue integrity, and increased the accumulation of proline and soluble protein, the chlorophyll content, and the activities of Ribulose-1,5-bisphosphate carboxylase and phosphoenolpyruvate carboxykinase. The net photosynthetic rate in the flag leaves of the YN19 and XM26 via LT2 increased by 37.9% and 35.9%, respectively, at 0-12 DALTT, compared to LT1. Moreover, spraying KH 2 PO 4 reduced the yield loss rate of the YN19 and XM26 by 13.06% and 16.72%, respectively. The present study demonstrates that spraying KH 2 PO 4 can enhance wheat resistance to spring LTS and maintain the photosynthetic capacity of flag leaves, alleviating the negative effects of LTS on grain yield.

The exploitation of drought is a critical worldwide challenge that influences wheat growth and productivity. This study aimed to investigate a synergistic amendment strategy for drought using the single and combined application of plant growth-promoting microorganisms (PGPM) ( Trichoderma harzianum ) and biogenic silica nanoparticles (SiO 2 NPs) from rice husk ash (RHA) on Saudi Arabia's Spring wheat Summit cultivar ( Triticum aestivum L.) for 102 DAS (days after sowing). The significant improvement was due to the application of 600 ppm SiO 2 NPs and T. harzianum + 600 ppm SiO 2 NPs, which enhanced the physiological properties of chlorophyll a, carotenoids, total pigments, osmolytes, and antioxidant contents of drought-stressed wheat plants as adaptive strategies. The results suggest that the expression of the studied genes ( TaP5CS1 , TaZFP34 , TaWRKY1 , TaMPK3 , TaLEA , and the wheat housekeeping gene TaActin ) in wheat remarkably enhanced wheat tolerance to drought stress. We discovered that the genes and metabolites involved significantly contributed to defense responses, making them potential targets for assessing drought tolerance levels. The drought tolerance indices of wheat were revealed by the mean productivity (MP), stress sensitivity index (SSI), yield stability index (YSI), and stress tolerance index (STI). We employed four databases, such as BAR, InterPro, phytozome, and the KEGG pathway, to predict and decipher the putative domains in prior gene sequencing. As a result, we discovered that these genes may be involved in a range of important biological functions in specific tissues at different developmental stages, including response to drought stress, proline accumulation, plant growth and development, and defense response. In conclusion, the sole and/or dual T. harzianum application to the wheat cultivar improved drought tolerance strength. These findings could be insightful data for wheat production in Saudi Arabia under various water regimes.

Background/Objectives: The phytosulfokine receptor ( PSKR ) gene family plays a crucial role in regulating plant growth, development, and stress response. Here, the PSKR gene family was characterized in Triticum aestivum L. The study aimed to bridge knowledge gaps and clarify the functional roles of TaPSKRs to create a solid foundation for examining the structure, functions, and regulatory aspects. Methods: The investigation involved genome-wide identification of PSKRs through collection and chromosomal assignment, followed by phylogenetic analysis and gene expression profiling. Additionally, interactions with their interactors were stimulated and analyzed to elucidate their function. Results: The wide-genome inspection of all TaPSKRs led to 25 genes with various homeologs, resulting in 57 TaPSKR members distributed among the A, B, and D subgenomes. Investigating the expression of 61 Ta PSKR cDNAs in RNA-seq datasets generated from different growth stages at 14, 21, and 60 days old and diverse tissues such as leaves, shoots, and roots provided further insight into their functional purposes. The expression profile of the TaPSKRs resulted in three key clusters. Gene cluster 1 (GC 1) is partially associated with root growth, suggesting that specific TaPSKR s control root development. The GC 2 cluster targeted genes that show high levels of expression in all tested leaf growth stages and the early developmental stage of the shoots and roots. Furthermore, the GC 3 cluster was composed of genes that are constantly expressed, highlighting their crucial role in regulating various processes during the entire life cycle of wheat. Molecular docking simulations showed that phytosulfokine type α (PSK-α) interacted with all Ta PSKRs and had a strong binding affinity with certain Ta PSKR proteins, encompassing Ta PSKR1A, Ta PSKR3B, and Ta PSKR13A, that support their involvement in PSK signaling pathways. The crucial arbitration of the affinity may depend on interactions between wheat PSK-α and PSKRs, especially in the LRR domain region. Conclusions: These discoveries deepened our knowledge of the role of the TaPSKR gene family in wheat growth and development, opening up possibilities for further studies to enhance wheat durability and yield via focused innovation approaches.

Wild and cultivated relatives of wheat are an important source of genetic factors for improving the mineral composition of wheat. In this work, a wheat panel consisting of modern bread wheat varieties, landraces, and introgression lines with genetic material of the wheat species Triticum timopheevii , T. durum , T. dicoccum , and T. dicoccoides and the synthetic line T. kiharae was used to identify loci associated with the grain zinc (GZnC) and iron (GFeC) content. Using a BLINK model, we identified 31 and 73 marker-trait associations (MTAs) for GZnC and GFeC, respectively, of which 19 were novel. Twelve MTAs distributed on chromosomes 1B, 2A, 2B, 5A, and 5B were significantly associated with GZnC, five MTAs on 2A, 2B, and 5D chromosomes were significantly associated with GFeC, and two SNPs located on 2A and 2B were related to the grain concentration of both trace elements. Meanwhile, most of these MTAs were inherited from A t and G genomes of T. timopheevii and T. kiharae and positively affected GZnC and GFeC. Eight genes related to iron or zinc transporters, representing diverse gene families, were proposed as the best candidates. Our findings provide an understanding of the genetic basis of grain Zn and Fe accumulation in species of the Timopheevi group and could help in selecting new genotypes containing valuable loci.

Wheat is the most widely grown crop in the world; its production is severely disrupted by increasing water deficit. Plant roots play a crucial role in the uptake of water and perception and transduction of water deficit signals. In the past decade, the mechanisms of drought tolerance have been frequently reported; however, the transcriptome and metabolome regulatory network of root responses to water stress has not been fully understood in wheat. In this study, the global transcriptomic and metabolomics profiles were employed to investigate the mechanisms of roots responding to water stresses using the drought-tolerant (DT) and drought-susceptible (DS) wheat genotypes. The results showed that compared with the control group, wheat roots exposed to polyethylene glycol (PEG) had 25941 differentially expressed genes (DEGs) and more upregulated genes were found in DT (8610) than DS (7141). Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that the DEGs of the drought-tolerant genotype were preferably enriched in the flavonoid biosynthetic process, anthocyanin biosynthesis and suberin biosynthesis. The integrated analysis of the transcriptome and metabolome showed that in DT, the KEGG pathways, including flavonoid biosynthesis and arginine and proline metabolism, were shared by differentially accumulated metabolites (DAMs) and DEGs at 6 h after treatment (HAT) and pathways including alanine, aspartate, glutamate metabolism and carbon metabolism were shared at 48 HAT, while in DS, the KEGG pathways shared by DAMs and DEGs only included arginine and proline metabolism at 6 HAT and the biosynthesis of amino acids at 48 HAT. Our results suggest that the drought-tolerant genotype may relieve the drought stress by producing more ROS scavengers, osmoprotectants, energy and larger roots. Interestingly, hormone signaling plays an important role in promoting the development of larger roots and a higher capability to absorb and transport water in drought-tolerant genotypes.

Cuticular wax mixtures cover the epidermis of land plants and shield plant tissues from abiotic and biotic stresses. Although cuticular wax-associated traits are employed to improve the production of bread wheat, regulatory mechanisms underlying wheat cuticular wax biosynthesis remain poorly understood. In this research, partially redundant transcription factors TaMYB60-1 and TaMYB60-2 were identified as positive regulators of wheat cuticular wax biosynthesis. Knock-down of wheat TaMYB60-1 and TaMYB60-2 genes by virus-induced gene silencing resulted in attenuated wax accumulation and enhanced cuticle permeability. The roles of wheat fatty acyl-ACP thioesterase genes TaFATB1 and TaFATB2 in cuticular wax biosynthesis were characterized. Silencing wheat TaFATB1 and TaFATB2 genes led to reduced wax accumulation and increased cuticle permeability, suggesting that TaFATB1 and TaFATB2 genes positively contribute to wheat cuticular wax biosynthesis. Importantly, transcription factors TaMYB60-1 and TaMYB60-2 exhibit transcriptional activation ability and could stimulate the expression of wax biosynthesis genes TaFATB1 , TaFATB2 , and ECERIFERUM 1 ( TaCER1 ). These findings support that transcription factor TaMYB60 positively regulates wheat cuticular wax biosynthesis probably by activating transcription of TaFATB1 , TaFATB2 , and TaCER1 genes.

Polyethylene terephthalate (PET) is one of the most produced plastic materials in the world. The emergence of microplastics and nanoplastics (MPs/NPs) as a significant environmental contaminant has become a matter of increasing concern. While the toxicological effects of PET NPs have been widely researched, there is a lack of methodologies for studying their accumulation. The present study introduces a novel method to monitor the distribution of PET NPs in germinating wheat ( Triticum aestivum L.) seeds. This involves the functionalization of superparamagnetic iron oxide nanoparticles (SPIONs) with PET NPs (PET-fSPIONs) coupled with magnetic resonance microimaging (µMRI) to provide insight into their distribution within the seed. The present study has demonstrated that PET-fSPIONs accumulate in specific regions of germinating wheat seeds, including the shoot apical meristem, the radicle, the coleoptile, the plumule, and the scutellum. Furthermore, the accumulation of PET-fSPIONs has been shown to exert a discernible effect on spin-spin relaxation ( T 2 ), as observed via MRI and quantitative T 2 relaxation time analysis. The accumulation of PET NPs in embryo regions was also confirmed by SEM. Diffusion-weighted magnetic resonance imaging (DW-MRI) and non-invasive chemical shift imaging analyses demonstrated that PET NPs resulted in restricted diffusion within the highlighted areas, as well as an impact on lipid content. Our study reveals that using µMRI with fSPIONs provides a non-invasive method to monitor the biodistribution of PET nanoparticles in wheat seeds. Additionally, it offers valuable insights into the microstructural interactions of PET.

Fertilization significantly affects the growth and development of wheat. However, the precise mechanisms underlying gene regulation during flowering in response to fertilization deficiency remain elusive. In this study, fertilization (F) and non-fertilization (CK) ) treatments were set up to reveal examine the effect of fertilization on the photosynthetic capacity of winter wheat during the flowering period through physiological, biochemical, and transcriptome analyses. Upon analyzing analysing their yield, leaf photosynthetic system exchange parameters during flowering, antioxidant enzyme activity, and endogenous hormone parameters, we found that the F treatment resulted in higher net photosynthetic rates during flowering periods than the CK treatment. The superoxide dismutase (SOD) (83.92%), peroxidase (POD) (150.75%), and catalase (CAT) (22.74%) activities of leaves in treated with F during the flowering period were notably elevated compared to those of CK-treated leaves. Abscisic acid (ABA) (1.86%) and gibberellin acid (GA3) (33.69%) levels were reduced, whereas Auxin auxin (IAA) (98.27%) content was increasedwas increased under F treatment compared to those the results under the CK treatment. The chlorophyll a (32.53%), chlorophyll b (56%), total chlorophyll (37.96%), and carotenoid contents (29.80%) under F treatment were also increased compared to CK., exceeded exceeding those obtained under the CK treatment. Furthermore, transcriptional differences between the F and CK conditions were analyzed, and key genes were screened and validated by using q-PCR. Transcriptome analysis identified 2281 differentially expressed genes (DEGs), with enriched pathways related to photosynthesis and light harvesting. DEGs were subjected to cluster simulation, which revealed that 53 DEGS, both up- and down-regulated, responded to the F treatment. qRT-PCR-based validation confirmed the differential expression of genes associated with carbohydrate transport and metabolism, lipid transport, and signal transduction. This study revealed distinctive transcriptional patterns and crucial gene regulation networks in wheat during flowering under fertilization, providing transcriptomic guidance for the precise regulation of wheat breeding.

The lateral root (LR) is an essential component of the plant root system, performing important functions for nutrient and water uptake in plants and playing a pivotal role in cereal crop productivity. Nitrate (NO 3 - ) is an essential nutrient for plants. In this study, wheat plants were grown in 1/2 strength Hoagland's solution containing 5 mM NO 3 - (check; CK), 0.1 mM NO 3 - (low NO 3 - ; LN), or 0.1 mM NO 3 - plus 60 mg/L 2,3,5-triiodobenzoic acid (TIBA) (LNT). The results showed that LN increased the LR number significantly at 48 h after treatment compared with CK, while not increasing the root biomass, and LNT significantly decreased the LR number and root biomass. The transcriptomic analysis showed that LN induced the expression of genes related to root IAA synthesis and transport and cell wall remodeling, and it was suppressed in the LNT conditions. A physiological assay revealed that the LN conditions increased the activity of IAA biosynthesis-related enzymes, the concentrations of tryptophan and IAA, and the activity of cell wall remodeling enzymes in the roots, whereas the content of polysaccharides in the LRP cell wall was significantly decreased compared with the control. Fourier-transform infrared spectroscopy and atomic microscopy revealed that the content of cell wall polysaccharides decreased and the cell wall elasticity of LR primordia (LRP) increased under the LN conditions. The effects of LN on IAA synthesis and polar transport, cell wall remodeling, and LR development were abolished when TIBA was applied. Our findings indicate that NO 3 - starvation may improve auxin homeostasis and the biological properties of the LRP cell wall and thus promote LR initiation, while TIBA addition dampens the effects of LN on auxin signaling, gene expression, physiological processes, and the root architecture.

Eukaryotic gene transcription is fine-tuned by precise spatiotemporal interactions between cis -regulatory elements (CREs) and trans -acting factors. However, how CREs individually or coordinated with epigenetic marks function in regulating homoeolog bias expression is still largely unknown in wheat. In this study, through comprehensively characterizing open chromatin coupled with DNA methylation in the seedling and spikelet of common wheat, we observed that differential chromatin openness occurred between the seedling and spikelet, which plays important roles in tissue development through regulating the expression of related genes or through the transcription factor (TF)-centered regulatory network. Moreover, we found that CHH methylation may act as a key determinant affecting the differential binding of TFs, thereby resulting in differential expression of target genes. In addition, we found that sequence variations in MNase hypersensitive sites (MHSs) result in the differential expression of key genes responsible for important agronomic traits. Thus, our study provides new insights into the roles of CREs in regulating tissue or homoeolog bias expression, and controlling important agronomic traits in common wheat. It also provides potential CREs for genetic and epigenetic manipulation toward improving desirable traits for wheat molecule breeding.

The mitigation mechanisms of a kind of controlled-release nitrogen fertilizer (sulfur-coated controlled-release nitrogen fertilizer, SCNF) in response to O 3 stress on a winter wheat ( Triticum aestivum L.) variety (Nongmai-88) were studied in crop physiology and soil biology through the ozone-free-air controlled enrichment (O 3 -FACE) simulation platform and soil microbial metagenomics. The results showed that SCNF could not delay the O 3 -induced leaf senescence of winter wheat but could enhance the leaf size and photosynthetic function of flag leaves, increase the accumulation of nutrient elements, and lay the foundation for yield by regulating the release rate of nitrogen (N). By regulating the soil environment, SCNF could maintain the diversity and stability of soil bacterial and archaeal communities, but there was no obvious interaction with the soil fungal community. By alleviating the inhibition effects of O 3 on N-cycling-related genes ( ko00910 ) of soil microorganisms, SCNF improved the activities of related enzymes and might have great potential in improving soil N retention. The results demonstrated the ability of SCNF to improve leaf photosynthetic function and increase crop yield under O 3 -polluted conditions in the farmland ecosystem, which may become an effective nitrogen fertilizer management measure to cope with the elevated ambient O 3 and achieve sustainable production.

Aluminum (Al) toxicity and low phosphorus availability (LP) are the top two co-existing edaphic constraints limiting agriculture productivity in acid soils. Plants have evolved versatile mechanisms to cope with the two stresses alone or simultaneously. However, the specific and common molecular mechanisms, especially those involving flavonoids and carbohydrate metabolism, remain unclear. Laboratory studies were conducted on two wheat genotypes-Fielder (Al-tolerant and P-efficient) and Ardito (Al-sensitive and P-inefficient)-exposed to 50 μM Al and 2 μM Pi (LP) in hydroponic solutions. After 4 days of stress, wheat roots were analyzed using transcriptomics and targeted metabolomics techniques. In Fielder, a total of 2296 differentially expressed genes (DEGs) were identified under Al stress, with 1535 upregulated and 761 downregulated, and 3029 DEGs were identified under LP stress, with 1591 upregulated and 1438 downregulated. Similarly, 4404 DEGs were identified in Ardito under Al stress, with 3191 upregulated and 1213 downregulated, and 1430 DEGs were identified under LP stress, with 1176 upregulated and 254 downregulated. GO annotation analysis results showed that 4079 DEGs were annotated to the metabolic processes term. These DEGs were significantly enriched in the phenylpropanoid, flavonoid, flavone and flavonol biosynthesis, and carbohydrate metabolism pathways by performing the KEGG enrichment analysis. The targeted metabolome analysis detected 19 flavonoids and 15 carbohydrate components in Fielder and Ardito under Al and LP stresses. In Fielder, more responsive genes and metabolites were involved in flavonoid metabolism under LP than Al stress, whereas the opposite trend was observed in Ardito. In the carbohydrate metabolism pathway, the gene and metabolite expression levels were higher in Fielder than in Ardito. The combined transcriptome and metabolome analysis revealed differences in flavonoid- and carbohydrate-related genes and metabolites between Fielder and Ardito under Al and LP stresses, which may contribute to Fielder's higher resistance to Al and LP. The results of this study lay a foundation for pyramiding genes and breeding multi-resistant varieties.

Understanding the mechanisms that regulate plant root growth under soil drying is an important challenge in root biology. We observed that moderate soil drying promotes wheat root growth. To understand whether metabolic and hormonic changes are involved in this regulation, we performed transcriptome sequencing on wheat roots under well-watered and moderate soil drying conditions. The genes upregulated in wheat roots under soil drying were mainly involved in starch and sucrose metabolism and benzoxazinoid biosynthesis. Various plant hormone-related genes were differentially expressed during soil drying. Quantification of the plant hormones under these conditions showed that the concentrations of abscisic acid (ABA), cis-zeatin (CZ), and indole-3-acetic acid (IAA) significantly increased during soil drying, whereas the concentrations of salicylic (SA), jasmonic (JA), and glycosylated salicylic (SAG) acids significantly decreased. Correlation analysis of total root length and phytohormones indicated that CZ, ABA, and IAA are positively associated with wheat root length. These results suggest that changes in metabolic pathways and plant hormones caused by moderate soil drying help wheat roots grow into deeper soil layers.

Triticum aestivum is an important crop whose reference genome (International Wheat Genome Sequencing Consortium (IWGSC) RefSeq v2.1) offers a valuable resource for understanding wheat genetic structure, improving agronomic traits, and developing new cultivars. A key aspect of gene model annotation is protein-level evidence of gene expression obtained from proteomics studies, followed up by proteogenomics to physically map proteins to the genome. In this research, we have retrieved the largest recent wheat proteomics datasets publicly available and applied the Basic Local Alignment Search Tool (tBLASTn) algorithm to map the 861,759 identified unique peptides against IWGSC RefSeq v2.1. Of the 92,719 hits, 83,015 unique peptides aligned along 33,612 High Confidence (HC) genes, thus validating 31.4% of all wheat HC gene models. Furthermore, 6685 unique peptides were mapped against 3702 Low Confidence (LC) gene models, and we argue that these gene models should be considered for HC status. The remaining 2934 orphan peptides can be used for novel gene discovery, as exemplified here on chromosome 4D. We demonstrated that tBLASTn could not map peptides exhibiting mid-sequence frame shift. We supply all our proteogenomics results, Galaxy workflow and Python code, as well as Browser Extensible Data (BED) files as a resource for the wheat community via the Apollo Jbrowse, and GitHub repositories. Our workflow could be applied to other proteomics datasets to expand this resource with proteins and peptides from biotically and abiotically stressed samples. This would help tease out wheat gene expression under various environmental conditions, both spatially and temporally.

Salt stress is a serious problem, because it reduces the plant growth and seed yield of wheat. To investigate the salt-tolerant mechanism of wheat caused by plant-derived smoke (PDS) solution, metabolomic and proteomic techniques were used. PDS solution, which repairs the growth inhibition of wheat under salt stress, contains metabolites related to flavonoid biosynthesis. Wheat was treated with PDS solution under salt stress and proteins were analyzed using a gel-free/label-free proteomic technique. Oppositely changed proteins were associated with protein metabolism and signal transduction in biological processes, as well as mitochondrion, endoplasmic reticulum/Golgi, and plasma membrane in cellular components with PDS solution under salt stress compared to control. Using immuno-blot analysis, proteomic results confirmed that ascorbate peroxidase increased with salt stress and decreased with additional PDS solution; however, H + -ATPase displayed opposite effects. Ubiquitin increased with salt stress and decreased with additional PDS solution; nevertheless, genomic DNA did not change. As part of mitochondrion-related events, the contents of ATP increased with salt stress and recovered with additional PDS solution. These results suggest that PDS solution enhances wheat growth suppressed by salt stress through the regulation of energy metabolism and the ubiquitin-proteasome system related to flavonoid metabolism.

To non-destructively and rapidly monitor the chlorophyll content of winter wheat leaves under CO 2 microleakage stress, and to establish the quantitative relationship between chlorophyll content and sensitive bands in the winter wheat growing season from 2023 to 2024, the leakage rate was set to 1 L/min, 3 L/min, 5 L/min, and 0 L/min through field experiments. The dimensional reduction was realized, fractional differential processing of a wheat canopy spectrum was carried out, a multiple linear regression (MLR) and partial least squares regression (PLSR) estimation model was constructed using a SPA selection band, and the model's accuracy was evaluated. The optimal model for hyperspectral estimation of wheat SPAD under CO 2 microleakage stress was screened. The results show that the spectral curves of winter wheat leaves under CO 2 microleakage stress showed a "red shift" of the green peak and a "blue shift" of the red edge. Compared with 1 L/min and 3 L/min, wheat leaves were more affected by CO 2 at 5 L/min. Evaluation of the accuracy of the MLR and PLSR models shows that the MLR model is better, where the MLR estimation model based on 1.1, 1.8, 0.4, and 1.7 differential SPAD is the best for leakage rates of 1 L/min, 3 L/min, 5 L/min, and 0 L/min, with validation set R 2 of 0.832, 0.760, 0.928, and 0.773, which are 11.528, 14.2, 17.048, and 37.3% higher than the raw spectra, respectively. This method can be used to estimate the chlorophyll content of winter wheat leaves under CO 2 trace-leakage stress and to dynamically monitor CO 2 trace-leakage stress in crops.

Recycling of unnecessary or dysfunctional cellular structures through autophagy plays a critical role in cellular homeostasis and environmental resilience. Therefore, the autophagy trait may have been unintentionally selected in wheat breeding programs for higher yields in arid climates. This hypothesis was tested by measuring the response of three common autophagy markers, ATG7, ATG8, and NBR1, to a heat wave under reduced soil moisture content in 16 genetically diverse spring wheat landraces originating from different geographical locations. We observed in the greenhouse trials that ATG8 and NBR1 exhibited genotype-specific responses to a 1 h, 40 °C heat wave, while ATG7 did not show a consistent response. Three genotypes from Uruguay, Mozambique, and Afghanistan showed a pattern consistent with higher autophagic activity: decreased or stable abundance of both ATG8 and NBR1 proteins, coupled with increased transcription of ATG8 and NBR1 . In contrast, three genotypes from Pakistan, Ethiopia, and Egypt exhibited elevated ATG8 protein levels alongside reduced or unaltered ATG8 transcript levels, indicating a potential suppression or no change in autophagic activity. Principal component analysis demonstrated a correlation between lower abundance of ATG8 and NBR1 proteins and higher yield in the field trials. We found that (i) the combination of heat and drought activated autophagy only in several genotypes, suggesting that despite being a resilience mechanism, autophagy is a heat-sensitive process; (ii) higher autophagic activity correlates positively with greater yield; (iii) the lack of autophagic activity in some high-yielding genotypes suggests contribution of alternative stress-resilient mechanisms; and (iv) enhanced autophagic activity in response to heat and drought was independently selected by wheat breeding programs in different geographic locations.

Expansin is a cell wall relaxant protein that is common in plants and directly or indirectly participates in the whole process of plant root growth, development and morphogenesis. A well-developed root system helps plants to better absorb water and nutrients from the soil while effectively assisting them in resisting osmotic stress, such as salt stress. In this study, we observed and quantified the morphology of the roots of Arabidopsis overexpressing the TaEXPAs gene obtained by the research group in the early stage of development. We combined the bioinformatics analysis results relating to EXPA genes in five plants and identified TaEXPA7-B , a member of the EXPA family closely related to root development in winter wheat. Subcellular localization analysis of the TaEXPA7-B protein showed that it is located in the plant cell wall. In this study, the TaEXPA7-B gene was overexpressed in rice. The results showed that plant height, root length and the number of lateral roots of rice overexpressing the TaEXPA7-B gene were significantly higher than those of the wild type, and the expression of the TaEXPA7-B gene significantly promoted the growth of lateral root primordium and cortical cells. The plants were treated with 250 mM NaCl solution to simulate salt stress. The results showed that the accumulation of osmotic regulators, cell wall-related substances and the antioxidant enzyme activities of the overexpressed plants were higher than those of the wild type, and they had better salt tolerance. This paper discusses the effects of winter wheat expansins in plant root development and salt stress tolerance and provides a theoretical basis and relevant reference for screening high-quality expansin regulating root development and salt stress resistance in winter wheat and its application in crop molecular breeding.

Wheat is one of the most important food crops globally, and understanding the regulation of grain size is crucial for wheat breeding to achieve a higher grain yield. MicroRNAs (miRNAs) play vital roles in plant growth and development. However, the miRNA-mediated mechanism underlying grain size regulation remains largely elusive in wheat. Here, we report the characterization and functional validation of a miRNA, TamiR397a, associated with grain size regulation in wheat. The function of three TaMIR397 homoeologs was determined through histochemical β-glucuronidase-dependent assay. MiRNA expression was detected using quantitative reverse transcription polymerase chain reaction (qRT-PCR), and the function of TamiR397a was validated through its transgenic overexpression and repression in wheat. It was found that TaMIR397-6A and TaMIR397-6B encode active TamiR397a. The expression profiling indicated that TamiR397a was differentially expressed in various tissues and gradually up-regulated during grain filling. The inhibition of TamiR397a perturbed grain development, leading to a decrease in grain size and weight. Conversely, the overexpression of TamiR397a resulted in increased grain size and weight by accelerating the grain filling process. Transcriptome analysis revealed that TamiR397a regulates a set of genes involved in hormone response, desiccation tolerance, regulation of cellular senescence, seed dormancy, and seed maturation biological processes, which are important for grain development. Among the down-regulated genes in the grains of the TamiR397a-overexpressing transgenic plants, 11 putative targets of the miRNA were identified. Taken together, our results demonstrate that TamiR397a is a positive regulator of grain size and weight, offering potential targets for breeding wheat with an increased grain yield.

Selenium (Se) is an essential trace element for humans. Low concentrations of Se can promote plant growth and development. Enhancing grain yield and crop Se content is significant, as major food crops generally have low Se content. Studies have shown that Se biofortification can significantly increase Se content in plant tissues. In this study, the genetic transformation of wheat was conducted to evaluate the agronomic traits of non-transgenic control and transgenic wheat before and after Se application. Se content, speciation, and transfer coefficients in wheat grains were detected. Molecular docking simulations and transcriptome data were utilized to explore the effects of selenium-binding protein-A TaSBP-A on wheat growth and grain Se accumulation and transport. The results showed that TaSBP-A gene overexpression significantly increased plant height (by 18.50%), number of spikelets (by 11.74%), and number of grains in a spike (by 35.66%) in wheat. Under normal growth conditions, Se content in transgenic wheat grains did not change significantly, but after applying sodium selenite, Se content in transgenic wheat grains significantly increased. Analysis of Se speciation revealed that organic forms of selenomethionine (SeMet) and selenocysteine (SeCys) predominated in both W48 and transgenic wheat grains. Moreover, TaSBP-A significantly increased the transfer coefficients of Se from solution to roots and from flag leaves to grains. Additionally, it was found that with the increase in TaSBP-A gene overexpression levels in transgenic wheat, the transfer coefficient of Se from flag leaves to grains also increased.

Higher-fungi xylotrophic basidiomycetes are known to be the reservoirs of bioactive metabolites. Currently, a great deal of attention has been paid to the exploitation of mycelial fungi products as an innovative alternative in crop protection. No data exist on the mechanisms behind the interaction between xylotrophic mushrooms' glycopolymeric substances and plants. In this study, the effects of basidiomycete metabolites on the morphophysiological and biochemical variables of wheat plants have been explored. Wheat ( Triticum aestivum L. cv. Saratovskaya 29) seedlings were treated with extracellular polysaccharides (EPSs) isolated from the submerged cultures of twenty basidiomycete strains assigned to 13 species and 8 genera. The EPS solutions at final concentrations of 15, 40, and 80 mg/L were applied to wheat seedlings followed by their growth for 10 days. In the plant samples, the biomass, length of coleoptile, shoot and root, root number, rate of lipid peroxidation by malondialdehyde concentration, content of hydrogen peroxide, and total phenols were measured. The peroxidase and superoxide dismutase activity were defined. Most of the EPS preparations improved biomass yields, as well as the morphological parameters examined. EPS application enhanced the activities of antioxidant enzymes and decreased oxidative damage to lipids. Judging by its overall effect on the growth indices and redox system of wheat plants, an EPS concentration of 40 mg/L has been shown to be the most beneficial compared to other concentrations. This study proves that novel bioformulations based on mushroom EPSs can be developed and are effective for wheat growth and antioxidative response. Phytostimulating properties found for EPSs give grounds to consider extracellular metabolites produced in the xylotrophic basidiomycete cultures as an active component capable of inducing plant responses to stress.

Nitrogen (N), as the main component of biological macromolecules, maintains the basic process of plant growth and development. GOGAT, as a key enzyme in the N assimilation process, catalyzes α-ketoglutaric acid and glutamine to form glutamate. In this study, six GOGAT genes in wheat ( Triticum aestivum L.) were identified and classified into two subfamilies, Fd-GOGAT ( TaGOGAT2s ) and NADH-GOGAT ( TaGOGAT3s ), according to the type of electron donor. Subcellular localization prediction showed that TaGOGAT3-D was localized in mitochondria and that the other five TaGOGATs were localized in chloroplasts. Via the analysis of promoter elements, many binding sites related to growth and development, hormone regulation and plant stress resistance regulations were found on the TaGOGAT promoters. The tissue-specificity expression analysis showed that TaGOGAT2s were mainly expressed in wheat leaves and flag leaves, while TaGOGAT3s were highly expressed in roots and leaves. The expression level of TaGOGATs and the enzyme activity of TaGOGAT3s in the leaves and roots of wheat seedlings were influenced by the treatment of N deficiency. This study conducted a systematic analysis of wheat GOGAT genes, providing a theoretical basis not only for the functional analysis of TaGOGATs , but also for the study of wheat nitrogen use efficiency (NUE).

MIXTA-like transcription factors AtMYB16 and AtMYB106 play important roles in the regulation of cuticular wax accumulation in dicot model plant Arabidopsis thaliana , but there are very few studies on the MIXTA-like transcription factors in monocot plants. Herein, wheat MIXTA-like transcription factors TaMIXTA1 and TaMIXTA2 were characterized as positive regulators of cuticular wax accumulation. The virus-induced gene silencing experiments showed that knock-down of wheat TaMIXTA1 and TaMIXTA2 expressions resulted in the decreased accumulation of leaf cuticular wax, increased leaf water loss rate, and potentiated chlorophyll leaching. Furthermore, three wheat orthologous genes of ECERIFERUM 5 ( TaCER5-1A , 1B , and 1D ) and their function in cuticular wax deposition were reported. The silencing of TaCER5 by BSMV-VIGS led to reduced loads of leaf cuticular wax and enhanced rates of leaf water loss and chlorophyll leaching, indicating the essential role of the TaCER5 gene in the deposition of wheat cuticular wax. In addition, we demonstrated that TaMIXTA1 and TaMIXTA2 function as transcriptional activators and could directly stimulate the transcription of wax biosynthesis gene TaKCS1 and wax deposition gene TaCER5 . The above results strongly support that wheat MIXTA-Like transcriptional activators TaMIXTA1 and TaMIXTA2 positively regulate cuticular wax accumulation via activating TaKCS1 and TaCER5 gene transcription.

Water deficit affects the growth as well as physiological and biochemical processes in plants. The aim of this study was to determine differences in physiological and biochemical responses to drought stress in two wheat cultivars-Chinese Spring (CS) and SQ1 (which are parents of a mapping population of doubled haploid lines)-and to relate these responses to final yield and agronomic traits. Drought stress was induced by withholding water for 14 days, after which plants were re-watered and maintained until harvest. Instantaneous gas exchange parameters were evaluated on the 3rd, 5th, 10th, and 14th days of seedling growth under drought. After 14 days, water content and levels of chlorophyll a + b , carotenoids, malondialdehyde, soluble carbohydrates, phenolics, salicylic acid, abscisic acid (ABA), and polyamines were measured. At final maturity, yield components (grain number and weight), biomass, straw weight, and harvest index were evaluated. Physiological and biochemical parameters of CS responded more than those of SQ1 to the 14-day drought, reflected in a greater reduction in final biomass and yield in CS. Marked biochemical differences between responses of CS and SQ1 to the drought were found for soluble carbohydrates and polyamines. These would be good candidates for testing in the mapping population for the coincidence of the genetic control of these traits and final biomass and yield.

To explore the possible novel microRNA (miRNA) regulatory pathways in Zhengmai 1860, a newly cultivated drought-tolerant wheat ( Triticum aestivum L.) cultivar, miRNA transcriptome sequencing of the flag leaves of Zhengmai 1860, drought-sensitive variety Zhoumai 18, and drought-resistant variety Bainong 207 was performed during the grain filling stage. We also observed changes in the chloroplast ultrastructure, phytohormone levels, and antioxidant- and photosynthesis-related physiological indicators in three wheat varieties. The results showed that the flag leaves of the drought-tolerant variety Zhengmai 1860 had higher chlorophyll contents and net photosynthetic rates than those of Zhoumai 18 under drought stress during the grain filling stage; in addition, the chloroplast structure was more complete. However, there was no significant difference between Zhengmai 1860 and Bainong 207. MiRNA transcriptome analysis revealed that the differential expression of the miRNAs and mRNAs exhibited variable specificity. The KEGG pathway enrichment results indicated that most of the genes were enriched in the MAPK signaling pathway, plant hormone signal transduction, photosynthetic antennae protein, and amino acid and carbohydrate metabolism. In the drought-tolerant cultivar Zhengmai 1860, tae-miR408 was targeted to regulate the allene oxide synthase (AOS) gene, inhibit its expression, reduce the AOS content, and decrease the synthesis of jasmonic acid (JA) and abscisic acid (ABA). The results of this study suggest that Zhengmai 1860 could improve the photosynthetic performance of flag leaves by inhibiting the expression of genes involved in the JA pathway through miRNAs under drought conditions. Moreover, multiple miRNAs may target chlorophyll, antioxidant enzymes, phytohormone signal transduction, and other related pathways; thus, it is possible to provide a more theoretical basis for wheat molecular breeding.

Floods induce hypoxic stress and reduce wheat growth. On the other hand, rice is a semi-aquatic plant and usually grows even when partially submerged. To clarify the dynamic differences in the cellular mechanism between rice and wheat under flooding stress, morphological and biochemical analyses were performed. Although the growth of wheat in the early stage was significantly suppressed due to flooding stress, rice was hardly affected. Amino-acid analysis revealed significant changes in amino acids involved in the gamma-aminobutyric acid (GABA) shunt and anaerobic/aerobic metabolism. Flood stress significantly increased the contents of GABA and glutamate in wheat compared with rice, though the abundances of glutamate decarboxylase and succinyl semialdehyde dehydrogenase did not change. The abundance of alcohol dehydrogenase and pyruvate carboxylase increased in wheat and rice, respectively. The contents of aspartic acid and pyruvic acid increased in rice root but remained unchanged in wheat; however, the abundance of aspartate aminotransferase increased in wheat root. These results suggest that flooding stress significantly inhibits wheat growth through upregulating amino-acid metabolism and increasing the alcohol-fermentation system compared to rice. When plant growth is inhibited by flooding stress and the aerobic-metabolic system is activated, GABA content increases.

Drought and salinity stress reduce root hydraulic conductivity of plant seedlings, and melatonin application positively mitigates stress-induced damage. However, the underlying effect of melatonin priming on root hydraulic conductivity of seedlings under drought-salinity combined remains greatly unclear. In the current report, we investigated the influence of seeds of three wheat lines' 12 h priming with 100 μM of melatonin on root hydraulic conductivity (Lpr) and relevant physiological indicators of seedlings under PEG, NaCl, and PEG + NaCl combined stress. A previous study found that the combined PEG and NaCl stress remarkably reduced the Lpr of three wheat varieties, and its value could not be detected. Melatonin priming mitigated the adverse effects of combined PEG + NaCl stress on Lpr of H4399, Y1212, and X19 to 0.0071 mL·h -1 ·MPa -1 , 0.2477 mL·h -1 ·MPa -1 , and 0.4444 mL·h -1 ·MPa -1 , respectively, by modulating translation levels of aquaporin genes and contributed root elongation and seedlings growth. The root length of H4399, Y1212, and X19 was increased by 129.07%, 141.64%, and 497.58%, respectively, after seeds pre-treatment with melatonin under PEG + NaCl combined stress. Melatonin -priming appreciably regulated antioxidant enzyme activities, reduced accumulation of osmotic regulators, decreased levels of malondialdehyde (MDA), and increased K + content in stems and root of H4399, Y1212, and X19 under PEG + NaCl stress. The path investigation displayed that seeds primed with melatonin altered the modification of the path relationship between Lpr and leaf area under stress. The present study suggested that melatonin priming was a strategy as regards the enhancement of root hydraulic conductivity under PEG, NaCl, and PEG + NaCl stress, which efficiently enhanced wheat resistant to drought-salinity stress.

Aphids are insect pests that suck phloem sap and introduce salivary proteins into plant tissues through saliva secretion. The effector of salivary proteins plays a key role in the modulation of host plant defense responses and enhancing aphid host adaptation. Based on previous transcriptome sequencing results, a candidate effector cyclin-dependent kinase-like (CDK) was identified from the grain aphid Sitobion avenae . In this study, the function of SaCDK in wheat defense response and the adaptation of S. avenae was investigated. Our results showed that the transient overexpression of SaCDK in tobacco Nicotiana benthamiana suppressed cell death triggered by mouse pro-apoptotic protein-BAX or Phytophthora infestans PAMP-INF1. SaCDK, delivered into wheat cells through a Pseudomonas fluorescens -mediated bacterial type III secretion system, suppressed callose deposition in wheat seedlings, and the overexpression of SaCDK in wheat significantly decreased the expression levels of salicylic acid and jasmonic acid signaling pathway-related genes phenylalanine ammonia lyase ( PAL ), pathogenesis-related 1 protein ( PR1 ), lipoxygenase ( LOX ) and Ω-3 fatty acid desaturase ( FAD ). In addition, aphid bioassay results showed that the survival and fecundity of S. avenae were significantly increased while feeding on the wheat plants carrying SaCDK. Taken together, our findings demonstrate that the salivary protein SaCDK is involved in inhibiting host defense response and improving its host adaptation, which lays the foundation to uncover the mechanism of the interaction of cereal aphids and host plants.

Hypoxia is one of the common abiotic stresses that negatively affects the development and productivity of agricultural crops. Quercetin is used to protect plants from oxidative stress when exposed to environmental stressors. O 2 deficiency leads to impaired development and morphometric parameters in wheat varieties Orenburgskaya 22 ( Triticum aestivum L.) and varieties Zolotaya ( Triticum durum Desf.). Cytological analysis revealed various types of changes in the cytoplasm under conditions of hypoxia and treatment with quercetin. The most critical changes in the cytoplasm occur in the Zolotaya variety during pretreatment with quercetin followed by hypoxia, and in the Orenburgskaya 22 variety during hypoxia. Quercetin has a protective effect only on the Orenburgskaya 22 variety, and also promotes a more effective recovery after exposure to low O 2 content. Hypoxia causes an increase in reactive oxygen species and activates the antioxidant system. It has been shown that the most active components of the antioxidant system in the Orenburgskaya 22 variety are MnSOD and Cu/ZnSOD, and in the Zolotaya variety GSH. We have shown that quercetin provides resistance only to the wheat genotype Orenburgskaya 22, as a protective agent against abiotic stress, which indicates the need for a comprehensive study of the effects of exogenous protectors before use in agriculture.

Members of the TaCKX gene family (GFM) encode oxidase/dehydrogenase cytokinin degrading enzymes (CKX), which play an important role in the homeostasis of phytohormones, affecting wheat development and productivity. Therefore, the objective of this investigation was to test how the expression patterns of the yield-related TaCKX genes and TaNAC2-5A ( NAC2 ) measured in 7 days after pollination (DAP) spikes and the seedling roots of parents are inherited to apply this knowledge in the breeding process. The expression patterns of these genes were compared between parents and their F 2 progeny in crosses of one mother with different paterns of awnless cultivars and reciprocal crosses of awned and awnless lines. We showed that most of the genes tested in the 7 DAP spikes and seedling roots of the F 2 progeny showed paternal expression patterns in crosses of awnless cultivars as well as reciprocal crosses of awned and awnless lines. Consequently, the values of grain yield in the F 2 progeny were similar to the pater; however, the values of seedling root mass were similar to the mother or both parents. The correlation analysis of TaCKX GFMs and NAC2 in spikes and spikes per seedling roots reveals that the genes correlate with each other specifically with the pater and the F 2 progeny or the mother and the F 2 progeny, which shape phenotypic traits. The numbers of spikes and semi-empty spikes are mainly correlated with the specific coexpression of the TaCKX and NAC2 genes expressed in spikes or spikes per roots of the pater and F 2 progeny. Variable regression analysis of grain yield and root mass with TaCKX GFMs and NAC2 expressed in the tested tissues of five crosses revealed a significant dependency of these parameters on the mother and F 2 and/or the pater and F 2 progeny. We showed that the inheritance of yield-related traits depends on the specific cooperative expression of some TaCKX GFMs, in some crosses coupled with NAC2 , and is strongly dependent on the genotypes used for the crosses. Indications for parental selection in the breeding of high-yielding lines are discussed.

The glycoside hydrolase 13 (GH13) family is crucial for catalyzing α-glucoside linkages, and plays a key role in plant growth, development, and stress responses. Despite its significance, its role in plants remains understudied. This study targeted four GH13 subgroups in wheat, identifying 66 GH13 members from the latest wheat database (IWGSC RefSeq v2.1), including 36 α-amylase (AMY) members, 18 1,4-α-glucan-branching enzyme (SBE) members, 9 isoamylase (ISA) members, and 3 pullulanase (PU) members. Chromosomal distribution reveals a concentration of wheat group 7 chromosomes. Phylogenetic analysis underscores significant evolutionary distance variations among the subgroups, with distinct molecular structures. Replication events shaped subgroup evolution, particularly in regard to AMY members. Subcellular localization indicates AMY member predominance in extracellular and chloroplast regions, while others localize solely in chloroplasts, confirmed by the heterologous expression of TaSEB16 and TaAMY1 in tobacco. Moreover, 3D structural analysis shows the consistency of GH13 across species. Promoter cis-acting elements are suggested to be involved in growth, stress tolerance, and starch metabolism signaling. The RNA-seq data revealed TaGH13 expression changes under drought and submergence stress, and significant expression variation was observed between strong and weak gluten varieties during seed germination using quantitative real-time PCR (qRT-PCR), correlating with seed starch content. These findings demonstrate the pivotal role of GH13 family gene expression in wheat germination, concerning variety preference and environmental stress. Overall, this study advances the understanding of wheat GH13 subgroups, laying the groundwork for further functional studies.

E3 ubiquitin ligases play a pivotal role in ubiquitination, a crucial post-translational modification process. Anaphase-promoting complex (APC), a large cullin-RING E3 ubiquitin ligase, regulates the unidirectional progression of the cell cycle by ubiquitinating specific target proteins and triggering plant immune responses. Several E3 ubiquitin ligases have been identified owing to advancements in sequencing and annotation of the wheat genome. However, the types and functions of APC E3 ubiquitin ligases in wheat have not been reported. This study identified 14 members of the APC gene family in the wheat genome and divided them into three subgroups (CCS52B, CCS52A, and CDC20) to better understand their functions. Promoter sequence analysis revealed the presence of several cis-acting elements related to hormone and stress responses in the APC E3 ubiquitin ligases in wheat. All identified APC E3 ubiquitin ligase family members were highly expressed in the leaves, and the expression of most genes was induced by the application of methyl jasmonate (MeJA). In addition, the APC gene family in wheat may play a role in plant defense mechanisms. This study comprehensively analyzes APC genes in wheat, laying the groundwork for future research on the function of APC genes in response to viral infections and expanding our understanding of wheat immunity mechanisms.