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Pyraclostrobin-based fungicides play an effective role in controlling fungal diseases and are extensively used in agriculture. However, there is concern regarding the potential adverse effects attributed to exposure to these fungicides on non-target organisms and consequent influence exerted on ecosystem functioning. Thus, it is essential to conduct studies with model organisms to determine the impacts of these fungicides on different groups of living organisms. The aim of this study was to examine the ecotoxicity associated with exposure to commercial fungicides containing pyraclostrobin. The focus of the analysis involved germination and initial development of seedlings of 4 plant models (Lactuca sativa, Raphanus sativus, Pennisetum glaucum and Triticum aestivum), in addition to determining the population growth rate and total carbohydrate content in microalga Raphidocelis subcapitata. The fungicide pyraclostrobin adversely influenced growth and development of the tested plants, indicating a toxic effect. The fungicide exerted a significant impact on the initial development of seedlings of all model species examined with T. aestivum plants displaying the greatest susceptibility to pyraclostrobin. Plants of this species exhibited inhibitory effects on both aerial parts and roots when treated with a concentration of 4.75 mg/L pyraclostrobin. In addition, the green microalga R. subcapitata was also significantly affected by the fungicide, especially at relatively high concentrations as evidenced by a reduction in total carbohydrate content. This commercial fungicide demonstrated potential phytotoxicity for the tested plant models and was also considered toxic to the selected microalgae, indicating an ecotoxic effect that might affect other organisms in aquatic environments. [ABSTRACT FROM AUTHOR]

Zinc (Zn) deficiency and salt stress are well-known soil problems and often happen parallelly in cultivated soils. In this study, Zn-amino acid complexes (Zn-AAc) were used as a source of Zn to determine their effects on salt-induced damage in wheat plants. The bread wheat (Triticum aestivum L. cvs. Kavir) was supplied with Zn-glycine (Zn-Gly), Zn-alanine (Zn-Ala), and ZnSO4 as Zn sources at three salinity levels (EC 2, 4 and 6 dS m-). Salinity caused a significant decrease in shoot dry matter and grain yield of wheat, but this negative effect was significantly improved by the application of Zn-AAc. Salt stress decreased shoot and grain Zn concentration, but this reduction was lower in plants supplied by Zn-AAc. Calcium (Ca) and potassium (K) concentrations were increased in a shoot by salinity stress while decreased in grain. Sodium (Na) concentration decreased in shoot and grain by using Zn-AAc. At all of the salinity levels, wheat supplied with Zn-AAc had lower lipid peroxidation compared to those grown under the ZnSO4 source. Application of Zn-AAc increased the activities of catalase (CAT) and superoxide dismutase (SOD) in the roots of wheat plants in saline conditions. Based on the results, the adverse effects of salinity stress on wheat plants can moderately improve with Zn-AAc application. [ABSTRACT FROM AUTHOR]

Wheat is the predominant crop worldwide, contributing approximately 20% of protein and calories to the human diet. However, the yield potential of wheat faces limitations due to pests, diseases, and abiotic stresses. Although conventional breeding has improved desirable traits, the use of modern transgenesis technologies has been limited in wheat in comparison to other crops such as maize and soybean. Recent advances in wheat gene cloning and transformation technology now enable the development of a super wheat consistent with the One Health goals of sustainability, food security, and environmental stewardship. This variety combines traits to enhance pest and disease resistance, elevate grain nutritional value, and improve resilience to climate change. In this review, we explore ways to leverage current technologies to combine and transform useful traits into wheat. We also address the requirements of breeders and legal considerations such as patents and regulatory issues. [ABSTRACT FROM AUTHOR]

The importance of monitoring and management of yellow rust, caused by Puccinia striiformis f. sp. tritici (Pst), has markedly increased in Russia over recent years because of intensifying negative effects of this destructive disease on wheat production. The Pst virulence survey was conducted in 2019–2021 in the European (North‐West, Volga, North Caucasus) and Asian (Siberia) parts of Russia, and the same 109 isolates have been genotyped here with 20 SSR markers. Fifty‐three multilocus genotypes (MLGs) were detected, seven of which occurred in two or more regions. The most frequent MLG was found in three European Pst collections (except Dagestan) and Siberia. SSR‐based variation within the regional collections was low because many MLGs were closely related. Nevertheless, each collection contained relatively different small genotype groups. No clear geographic structure of the Russian Pst population was observed because the five studied regional collections shared groups of similar genotypes. The most singular SSR genotype was identified in the North‐West collection, but genotypes of four invasive isolates belonging to the PstS2 temperature‐adapted aggressive strain did not considerably differ from others. The observed heterozygosity at all SSR loci exceeded the expected one in all regional Pst collections, which could imply asexual reproduction of the pathogen. Both the SSR and virulence analyses demonstrated similar patterns of relationships between the regional Pst collections, although the magnitude of differences between the collections was larger for virulence pathotypes. However, no significant association was established between the virulence pathotypes and SSR genotypes because multiple pathotypes had the same genotype and vice versa. [ABSTRACT FROM AUTHOR]

The stress-protective effect of melatonin (N-acetyl-5-methoxytryptamine) on plant cells is mediated by key signaling mediators, in particular calcium ions and reactive oxygen species (ROS). However, the links between changes in calcium and redox homeostasis and the formation of adaptive responses of cultivated cereals (including wheat) to the action of high temperatures have not yet been studied. In the present study, we investigated the possible involvement of ROS and calcium ions as signaling mediators in developing heat resistance in wheat (Triticum aestivum L.) seedlings and activating their antioxidant system. Treatment of 3-day-old etiolated seedlings with melatonin solutions at concentrations 0.01–10 µM increased their survival after exposure to 45 °C for 10 min. The most significant stress-protective effect was exerted by melatonin treatment at 1 µM concentration. Under the influence of melatonin, a transient enhancement of superoxide anion radical (O2•–) generation and an increase in hydrogen peroxide content were observed in roots, with a maximum at 1 h. Four hours after treatment with melatonin, the activity of catalase and guaiacol peroxidase increased in roots, while the activity of superoxide dismutase did not change significantly. After exposure to 45 °C, the activity of catalase and guaiacol peroxidase was higher in the roots of melatonin-treated wheat seedlings, and the indices of ROS generation, content of the lipid peroxidation product malonic dialdehyde, and cell membrane damage were lower than in control seedlings. Melatonin-induced changes in root ROS generation and antioxidant enzyme activities were eliminated by pretreatment with the hydrogen peroxide scavenger dimethylthiourea (DMTU), NADPH oxidase inhibitor imidazole, and calcium antagonists (the extracellular calcium chelator EGTA and phospholipase C inhibitor neomycin). Treatment with DMTU, imidazole, EGTA, and neomycin also abolished the melatonin-induced increase in survival of wheat seedlings after heat stress. The role of calcium ions and ROS, generated with the participation of NADPH oxidase, as signaling mediators in the melatonin-induced antioxidant system and heat stress resistance of wheat seedlings have been demonstrated. [ABSTRACT FROM AUTHOR]

Wheat is a crop of great food importance for food production in Brazil. However, the improvement of this crop is still concentrated in isolated areas, which hinders advances in new cultivation regions due to the extensive demand for existing information. In this investigation, four wheat genotypes analysed to study associations and interrelationships between wheat traits across nine environments during the agricultural years of 2016, 2017 and 2018. The experiment was conducted using a randomised block design with four repetitions, and the analysis was divided into two groups: morphological and productive traits of wheat, comprising three and eleven characteristics, respectively. Canonical correlations between the morphological and productive groups were found to be dependent in most environments. Taller plants with longer main spikes and longer tiller spikes can be indirectly selected to increase grain yield under different sowing conditions. The information generated in this study indicate that some care must be taken when using the interrelations between trait groups to select or recommend genotypes for broader regions, as these relationships are influenced by the specific conditions of each region and sub-region. [ABSTRACT FROM AUTHOR]

SUMMARY Strigolactones (SLs) are key regulators of shoot growth and responses to environmental stimuli. Numerous studies have indicated that nitrogen (N) limitation induces SL biosynthesis, suggesting that SLs may play a pivotal role in coordinating systemic responses to N availability, but this idea has not been clearly demonstrated. Here, we generated triple knockout mutants in the SL synthesis gene TaDWARF17 (TaD17) in bread wheat and investigated their phenotypic and transcriptional responses under N limitation, aiming to elucidate the role of SLs in the adaptation to N limitation. Tad17 mutants display typical SL mutant phenotypes, and fail to adapt their shoot growth appropriately to N. Despite exhibiting an increased tillering phenotype, Tad17 mutants continued to respond to N limitation by reducing tiller number, suggesting that SLs are not the sole regulators of tillering in response to N availability. RNA‐seq analysis of basal nodes revealed that the loss of D17 significantly altered the transcriptional response of N‐responsive genes, including changes in the expression profiles of key N response master regulators. Crucially, our findings suggest that SLs are required for the transcriptional downregulation of cytokinin (CK) synthesis and signalling in response to N limitation. Collectively, our results suggest that SLs are essential for the appropriate morphological and transcriptional adaptation to N limitation in wheat, and that the repressive effect of SLs on shoot growth is partly mediated by their repression of CK synthesis. [ABSTRACT FROM AUTHOR]

Wheat cultivar Zhongmai 895 was earlier found to carry YR86 in an 11.6 Mb recombination-suppressed region on chromosome 2AL when crossed with Yangmai 16. To fine-map the YR86 locus, we developed two large F2 populations from crosses Emai 580/Zhongmai 895 and Avocet S/Zhongmai 895. Remarkably, both populations exhibited suppressed recombination in the same 2AL region. Collinearity analysis across Chinese Spring, Aikang 58, and 10+ wheat genomes revealed a 4.1 Mb chromosomal inversion spanning 708.5-712.6 Mb in the Chinese Spring reference genome. Molecular markers were developed in the breakpoint and were used to assess a wheat cultivar panel, revealing that Chinese Spring, Zhongmai 895, and Jimai 22 shared a common sequence named InvCS, whereas Aikang 58, Yangmai 16, Emai 580, and Avocet S shared the sequence named InvAK58. The inverted configuration explained the suppressed recombination observed in all three bi-parental populations. Normal recombination was observed in a Jimai 22/Zhongmai 895 F2 population, facilitating mapping of YR86 to a genetic interval of 0.15 cM corresponding to 710.27-712.56 Mb falling within the inverted region. Thirty-three high-confidence genes were annotated in the interval using the Chinese Spring reference genome, with six identified as potential candidates for YR86 based on genome and transcriptome analyses. These results will accelerate map-based cloning of YR86 and its deployment in wheat breeding. [ABSTRACT FROM AUTHOR]

In light of projected climate changes that are expected to disrupt crop yields in previously stable regions, it is essential to understand how these changes will affect food supplies. This study investigated the combined effect of light and temperature on the yield of wheat (Triticum aestivum L.) and rice (Oryza sativa L.) in a controlled environment. Three treatment combinations were tested: 30.2 mol.m−2.d−1 with a 17.5 °C average ("low"), 38.9 mol.m−2.d−1 and 22.5 °C ("medium"), and 47.5 mol.m−2.d−1 and 27.5 °C ("high"). The low treatment resulted in the highest wheat yield, with total dry biomasses of 233 g, 140 g, and 115 g for the low, medium, and high treatments. Rice showed the highest growth in the medium and high treatments, with total dry biomasses of 145 and 144 g. The medium and high treatment biomasses were not statistically significant for wheat or rice at 95% confidence. However, the wheat's edible biomass did significantly decrease between every treatment. These results demonstrate that wheat thrives in colder climates, even with less light available, while an increase in temperature will have either a positive or insignificant effect on rice within this study's temperature range. [ABSTRACT FROM AUTHOR]

Summary: High‐throughput genotyping arrays have provided a cost‐effective, reliable and interoperable system for genotyping hexaploid wheat and its relatives. Existing, highly cited arrays including our 35K Wheat Breeder's array and the Illumina 90K array were designed based on a limited amount of varietal sequence diversity and with imperfect knowledge of SNP positions. Recent progress in wheat sequencing has given us access to a vast pool of SNP diversity, whilst technological improvements have allowed us to fit significantly more probes onto a 384‐well format Axiom array than previously possible. Here we describe a novel Axiom genotyping array, the 'Triticum aestivum Next Generation' array (TaNG), largely derived from whole genome skim sequencing of 204 elite wheat lines and 111 wheat landraces taken from the Watkins 'Core Collection'. We used a novel haplotype optimization approach to select SNPs with the highest combined varietal discrimination and a design iteration step to test and replace SNPs which failed to convert to reliable markers. The final design with 43 372 SNPs contains a combination of haplotype‐optimized novel SNPs and legacy cross‐platform markers. We show that this design has an improved distribution of SNPs compared to previous arrays and can be used to generate genetic maps with a significantly higher number of distinct bins than our previous array. We also demonstrate the improved performance of TaNGv1.1 for Genome‐wide association studies (GWAS) and its utility for Copy Number Variation (CNV) analysis. The array is commercially available with supporting marker annotations and initial genotyping results freely available. [ABSTRACT FROM AUTHOR]

The genus Clavibacter (family Microbacteriaceae) includes gram‐positive actinobacterial species infecting diverse agricultural crops such as alfalfa, maize, pepper, potato, tomato and wheat. Clavibacter tessellarius, causing bacterial mosaic of wheat, was reported for the first time in 1976 in Nebraska (United States). Since then, the pathogen was thought to be restricted to North America (Canada and the United States). While bacterial strains suspected to be C. tessellarius have occasionally been isolated from wheat samples outside North America, occurrence of the pathogen in the Old World has not yet been confirmed by the plant protection authorities. In spring 2020 (January to May) dozens of wheat fields with young plants showing leaf chlorosis and mild mosaic symptoms were surveyed and sampled in southern Iran. Among 192 surveyed wheat fields, gram‐positive, orange‐pigmented actinobacterial strains were isolated from samples of 53 fields. Altogether, 61 bacterial strains were identified as C. tessellarius based on the phenotypic features, PCR‐based molecular tests and pathogenicity assays. Multilocus sequence analysis of five housekeeping genes (atpD, dnaK, gyrB, ppk and rpoB) using 10 representative strains from diverse geographic areas in southern Iran confirmed the phylogenetic status of the strains within C. tessellarius. Our data indicate that the bacterial mosaic pathogen occurs in four southern Iranian provinces including Bushehr, Fars, Kerman and Khuzestan. Thus, occurrence of C. tessellarius outside North America is confirmed. Potential risks associated with the emergence of the pathogen in the Old World, and the need for strict quarantine measures in the area, is further discussed. [ABSTRACT FROM AUTHOR]

Soil salinization restricts crop growth and yield, thereby adversely affecting agricultural development. The stage of seed germination is the most crucial and sensitive stage in the plants' life cycle and is particularly sensitive to saline-alkali stress. We investigated the effects of different hormonal priming agents, namely melatonin (MT), abscisic acid (ABA) and brassinosteroid (BR), as well as the osmopriming agent, calcium chloride (CaCl2), on the germination of wheat (Triticum aestivum L.) seeds under saline-alkali stress. Saline-alkali stress was simulated with the solution of 100 mM NaCl and 50 mM NaHCO3/Na2CO3 (9:1). The results indicated that hormonal priming agents (ABA, MT, or BR) significantly alleviated saline-alkali stress-induced inhibition of wheat seed germination. The germination rate of seeds primed with ABA, MT, or BR increased by 21.0%, 11.0%, and 10.5%, respectively. The seeds primed with ABA, MT or BR showed improved activities of α- and β-amylase under saline-alkali stress, with corresponding increases in starch hydrolysis and soluble sugar content, which contributed to seed germination and embryo growth. Hormonal priming (ABA, MT, or BR) also significantly improved antioxidase activities to alleviate oxidative damage in germinating seeds under saline-alkali stress. Seeds primed with ABA (38.7%), MT (37.0%), and BR (31.3%) displayed lower malondialdehyde (MDA) content than the H2O-primed seeds. The ABA exerted the most significant promoting effect on wheat seed germination under saline-alkali stress. The promotional effect of CaCl2 on seed germination was nonsignificant compared with that of hydropriming. The results offer a theoretical and practical basis for applying seed priming to enhance the saline-alkali tolerance of wheat in production. [ABSTRACT FROM AUTHOR]

AbstractSoil acidity has negative effects on both plants and soil. Furthermore, liming is the most common and effective management practice used to neutralize the acid produced in the soil and the problems associated with soil acidification. The study evaluated whether liming impacts wheat growth, yield, nutritional status basis exchangeable, and their related soil acidity indices. A greenhouse experiment was performed under a completely randomized arrangement, with four lime application rates equivalent to (0, 4.0, 8.0, and 12.0 Mg ha−1). The results showed that all yield components significantly increased with increasing lime addition rate. The grain yield, shoot and root dry weight, and plant and spike height improved quadratically (R2 = 0.909, 0.950, 0.976, 0.902, and 0.891, respectively). Additionally, the lime rate influenced P and Mg concentrations in the shoot, and the concentrations of Cu and Zn. With increasing lime rate, the soil exchangeable Ca and Mg concentrations increased quadratically (R2 = 0.969 and 0.984), while the soil exchangeable K and Al concentrations decreased significantly. The pH of the soil solution increased linearly (R2 = 0.994) with the lime addition rate. Liming significantly reduced the exchangeable Al3+ and Al + H in the soil. Finally, liming improves wheat yield in acid soil by reducing the negative effects of Al and H by increasing soil pH, Ca2+, and Mg2+ concentration, consequently improving root growth and resulting in wheat yield. Liming increased the grain yield by 188.7, 198.2, and 322.8% following the increase of lime rate, if compared to the control. Furthermore, lime enhances plant resilience by raising pH and improving soil nutrient availability and the root system. [ABSTRACT FROM AUTHOR]

Spring wheat (Triticum aestivum L.) remains an important alternative to winter wheat cultivation at Northern latitudes due to high risk of overwintering or delayed sowing of winter wheat. We studied nine major agronomic traits in a set of 299 spring wheat genotypes in trials across 12-year-site combinations in Lithuania, Latvia, Estonia, and Norway for three consecutive years. The dataset analyzed here consisted of previously published phenotypic data collected in 2021 and 2022, supplemented with additional phenotypic data from the 2023 field season collected in this study. We combined these phenotypic datasets with previously published genotypic data generated using a 25K single nucleotide polymorphism (SNP) array that yielded 18,467 markers with a minor allele frequency above 0.05. Analysis of these datasets via genome-wide association study revealed 18 consistent quantitative trait loci (QTL) replicated in two or more trials that explained more than 5% of phenotypic variance for plant height, grain protein content, thousand kernel weight, or heading date. The most consistent markers across the tested environments were detected for plant height, thousand kernel weight, and days to heading in eight, five, and six trials, respectively. No beneficial effect of the semi-dwarfing alleles Rht-B1b and Rht-D1b on grain yield performance was observed across the 12 tested trials. Moreover, the cultivars carrying these alleles were low yielding in general. Based on principal component analysis, wheat genotypes developed in the Northern European region clustered separately from those developed at the southern latitudes, and markers associated with the clustering were identified. Important phenotypic traits, such as grain yield, days to heading, grain protein content, and thousand kernel weight were associated with this clustering of the genotype sets. Interestingly, despite being adapted to the Nordic environment, genotypes in the Northern set demonstrated lower grain yield performance across all tested environments. The results indicate that spring wheat germplasm harbors valuable QTL/alleles, and the identified traitmarker associations might be useful in improving Nordic-Baltic spring wheat germplasm under global warming conditions. [ABSTRACT FROM AUTHOR]

There are doubts about nitrogen (N) management and the use of growth regulator in wheat. Thus, the objective was to evaluate the wheat performance as a function of topdressing N applied at different phenological stages of crop, and the use of trinexapac-ethyl (TE) growth regulator associated with N fertilization in subtropical regions in southern Brazil. In each environment, two experiments were carried out, all with an experimental design in 2 × 4 factorial scheme. The factors in experiment 1 were topdressing N application at seedling emergence and tillering stages and N rates (0, 40, 80, and 120 kg N ha−1); and in experiment 2: use of TE (with and without) and N rates (0, 40, 80, and 120 kg N ha−1) applied at tillering. The augment of N in topdressing increases the lodging. The use of TE minimizes the lodging. In environment with irrigation, the application of intermediate N rates at crop emergence reduces lodging. The yield components are altered by the rates and stages of N application, with variable responses according to the cultivation environment. The stage of application does not affect grain yield. N fertilization increases the yield, being that in Ponta Grossa the wheat is more responsive to higher N input. In certain environments, TE reduces the number of spikes m−2 and increases the number of grains per spike. TE impairs yield when associated with N non-application in topdressing. On the other hand, it maximizes the effect of N fertilization on yield, when using higher N rates in topdressing. [ABSTRACT FROM AUTHOR]

SUMMARY Plant fungal parasites manipulate host metabolism to support their own survival. Among the many central metabolic pathways altered during infection, the glyoxylate cycle is frequently upregulated in both fungi and their host plants. Here, we examined the response of the glyoxylate cycle in bread wheat (Triticum aestivum) to infection by the obligate biotrophic fungal pathogen Puccinia striiformis f. sp. tritici (Pst). Gene expression analysis revealed that wheat genes encoding the two unique enzymes of the glyoxylate cycle, isocitrate lyase (TaICL) and malate synthase, diverged in their expression between susceptible and resistant Pst interactions. Focusing on TaICL, we determined that the TaICL B homoeolog is specifically upregulated during early stages of a successful Pst infection. Furthermore, disruption of the B homoeolog alone was sufficient to significantly perturb Pst disease progression. Indeed, Pst infection of the TaICL‐B disruption mutant (TaICL‐BY400*) was inhibited early during initial penetration, with the TaICL‐BY400* line also accumulating high levels of malic acid, citric acid, and aconitic acid. Exogenous application of malic acid or aconitic acid also suppressed Pst infection, with trans‐aconitic acid treatment having the most pronounced effect by decreasing fungal biomass 15‐fold. Thus, enhanced TaICL‐B expression during Pst infection may lower accumulation of malic acid and aconitic acid to promote Pst proliferation. As exogenous application of aconitic acid and malic acid has previously been shown to inhibit other critical pests and pathogens, we propose TaICL as a potential target for disruption in resistance breeding that could have wide‐reaching protective benefits for wheat and beyond. [ABSTRACT FROM AUTHOR]

Efficient use of nitrogen (N) and phosphorus (P) is essential to reduce fertilizer costs and nutrient pollution and to lower the carbon footprint of agriculture. This requires a better understanding of N and P limitations on photosynthesis and biomass generation in one of the world's most important crops, wheat (Triticum aestivum). In a fully factorial nutrient experiment, we find that the limiting nutrient, N or P, at a Redfield‐like N:P ratio (21N:1P molar) produces the 'effective dose of fertilizer' for the generation of above‐ground biomass (seed or vegetative). Best‐fit structural equation models showed that neither N nor P applied in excess of 21N:1P led to any increase in biomass. The light (qP, NPQ) and dark (Amax, Vcmax, Jmax) reactions of photosynthesis are also constrained by the limiting nutrient at the 21N:1P Redfield‐like ratio. Beyond this ratio, 'excess N' or 'excess P' had no effects. The direct effects of the 'effective dose of fertilizer' on the accumulation of biomass were stronger than its indirect effects via photosynthesis, likely driven by the N and P costs in building nucleic acids needed for cell division, cell maintenance and RNA transcription. Modern composite fertilizers are typically provided at a much higher P content than a 21N:1P ratio, potentially resulting in a huge global wastage of P, a finite resource, with all the concomitant costs to the farmer, consumer and the environment. [ABSTRACT FROM AUTHOR]

SUMMARY Septoria nodorum blotch (SNB), caused by Parastagonospora nodorum, is a disease of durum and common wheat initiated by the recognition of pathogen‐produced necrotrophic effectors (NEs) by specific wheat genes. The wheat gene Snn1 was previously cloned, and it encodes a wall‐associated kinase that directly interacts with the NE SnTox1 leading to programmed cell death and ultimately the development of SNB. Here, sequence analysis of Snn1 from 114 accessions including diploid, tetraploid, and hexaploid wheat species revealed that some wheat lines possess two copies of Snn1 (designated Snn1‐B1 and Snn1‐B2) approximately 120 kb apart. Snn1‐B2 evolved relatively recently as a paralog of Snn1‐B1, and both genes have undergone diversifying selection. Three point mutations associated with the formation of the first SnTox1‐sensitive Snn1‐B1 allele from a primitive wild wheat were identified. Four subsequent and independent SNPs, three in Snn1‐B1 and one in Snn1‐B2, converted the sensitive alleles to insensitive forms. Protein modeling indicated these four mutations could abolish Snn1–SnTox1 compatibility either through destabilization of the Snn1 protein or direct disruption of the protein–protein interaction. A high‐throughput marker was developed for the absent allele of Snn1, and it was 100% accurate at predicting SnTox1‐insensitive lines in both durum and spring wheat. Results of this study increase our understanding of the evolution, diversity, and function of Snn1‐B1 and Snn1‐B2 genes and will be useful for marker‐assisted elimination of these genes for better host resistance. [ABSTRACT FROM AUTHOR]

Aims: Root system architecture (RSA) plays an important role in the plant’s ability to sustain yield under abiotic stresses such as drought. Preceding crops (precrops) can affect the yield of the proceeding crop, partially by affecting the RSA. This experiment aims to explore the interactions between precrop identity, crop genotype and drought at early growth stages. Methods: Rhizotrons, sized 60 × 80 × 3.5 cm, were used to assess the early root growth of two winter wheat (Triticum aestivum L.) genotypes, using precroptreated soil around the seedlings and differing water regimes. The rhizotrons were automatically imaged 3 times a week to track root development. Results: Precrop-treated soil affected the RSA and changes caused by the reduced water treatment (RWT) were different depending on the precrop. Largest of these was the 36% reduction in root depth after wheat, but 44% after OSR. This indicates that effects caused by the precrop can be simulated, at least partially, by transferring precrop-treated soils to controlled environments. The genotypes had differential RSA and reacted differently to the RWT, with Julius maintaining an 8.8-13.1% deeper root system compared to Brons in the RWT. In addition, the combined environmental treatment affected the genotypes differently. Conclusion: Our results could help explain discrepancies found from using precrops to enhance yield as they indicate differences in the preceding crop effect when experiencing drought stress. Further, these differences are affected by genotypic interactions, which can be used to select and adapt crop genotypes for specific crop rotations, depending on the year. Additionally, we have shown a viable method of stimulating a partial precrop effect at the seedling stage in a controlled greenhouse setting using field soil around the germinated seed. [ABSTRACT FROM AUTHOR]

The use of rhizospheric SynComs can be a new and sustainable strategy in the agrobiotechnology sector. The objective of this study was to create the most appropriate SynCom composition; examine the ability to dissolve natural rock phosphate (RP) from Morocco in liquid-modified NBRIP medium; determine organic acids, and phytohormones; and verify plant growth promoting and nutrition uptake effect in the pot experiments of winter wheat (Triticum aestivum). A total of nine different microorganisms were isolated, which belonged to three different genera: Bacillus, Pseudomonas, and Streptomyces. Out of the 21 treatments tested, four SynComs had the best phosphate-dissolving properties: IJAK-27+44+91 (129.17 mg L−1), IIBEI-32+40 (90.95 µg mL−1), IIIDEG-45+41 (122.78 mg L−1), and IIIDEG-45+41+72 (120.78 mg L−1). We demonstrate that these SynComs are capable of producing lactic, acetic, gluconic, malic, oxalic, citric acids, and phytohormones such as indole-3-acetic acid, zeatin, gibberellic acid, and abscisic acid. In pot experiments with winter wheat, we also demonstrated that the designed SynComs were able to effectively colonize the plant root rhizosphere and contributed to more abundant plant growth characteristics and nutrient uptake as uninoculated treatment or uninoculated treatment with superphosphate (NPK 0-19-0). The obtained results show that the SynCom compositions of IJAK-27+44+91, IIBEI-32+40, IIIDEG-45+41, and IIIDEG-45+41+72 can be considered as promising candidates for developing biofertilizers to facilitate P absorption and increase plant nutrition. [ABSTRACT FROM AUTHOR]

Hessian fly (HF), Mayetiola destructor, is a major insect pest that causes severe losses in grain yield and quality of wheat (Triticum aestivum). Growing resistant cultivars is the most cost-effective approach to minimize wheat yield losses caused by HF. In this study, 2,496 wheat accessions were screened for resistance to the HF biotype 'Great Plains' (GP) in the greenhouse experiments. To purify seeds from heterogeneous resistant accessions, we recovered single resistant plants from 331 accessions that had at least one resistant plant after HF infestation of a global collection of 1,595 accessions and confirmed 27 accessions with high resistance (HR), and 91 accessions with moderate resistance (MR) to the GP biotype using purified seeds. Screening of 203 U.S. winter wheat accessions in three experiments identified 63 HR and 28 MR accessions; and screening of three additional Asian panels identified 4 HR and 25 MR accessions. Together, this study identified 96 HR accessions and 144 MR accessions. Analysis of the geographic distribution of these HR and MR accessions revealed that these countries with HF as a major wheat pest usually showed higher frequencies of resistant accessions, with the highest frequency of HR (81.3%) and MR (30.6%) accessions identified from the U.S. In addition, phenotyping of 39 wheat accessions that carry known HF resistance genes showed that all the accessions except H1H2 remain effective against GP biotype. Some of these newly identified resistant accessions may contain new HF resistance genes and can be valuable sources for developing HF resistant wheat cultivars. [ABSTRACT FROM AUTHOR]

The fall armyworm (FAW), Spodoptera frugiperda , poses a significant global threat to agriculture due to its wide geographic range, high reproductive rate, and ability to thrive in diverse climates and habitats. A field study was conducted to evaluate the potential of nano-inert dust particles, specifically nano-diatomaceous earth (N-DE) and nano-potassium silicate (N-K 2 SiO 3), individually and in combination with emamectin benzoate, to manage FAW larvae infesting wheat plants (Triticum aestivum L.). The field experiments occurred during the winter seasons of 2021 and 2022 in Qaha, Qalubya Governorate, Egypt. Results revealed that the combined application of N-DE and N-K 2 SiO 3 with emamectin benzoate outperformed other treatments, achieving larval reduction rates of 93.33 % and 86.66 % in 2021 and 89.31 % and 86.90 % in 2022 after a 10-day interval from the second spray. Moreover, supplementation with N-DE and N-K 2 SiO 3 enhanced plant height, tiller count, leaf number, foaming, suspensibility, surface tension, and pH compared to using emamectin benzoate alone. Additionally, foliar application of N-K 2 SiO 3 and N-DE increased total flavonoids (4.23 and 3.24 mg CE/g) and total phenolic compounds (1.35 and 1.12 mg/g F. Wt.), as well as plant silicate content, indicating improved plant health and pest resistance. This study underscores the efficacy of N-DE and N-K 2 SiO 3 in reducing FAW infestations and enhancing plant growth and defense mechanisms. [Display omitted] • FAW poses a significant threat to agriculture globally due to its wide geographic range, and reproductive rate. • A field study assessed the potential of nano-diatomaceous earth (N-DE) and nano-potassium silicate (N-K 2 SiO 3). • Combined application of N-DE and N-K 2 SiO 3 with emamectin benzoate give superior efficacy in larval reduction. • Supplementation of N-DE and N-K 2 SiO 3 showed positive effects on wheat plants, enhancing plant parameters. • Application of N-K 2 SiO 3 and N-DE led to increased levels of total flavonoids and phenolic compounds in wheat plants. [ABSTRACT FROM AUTHOR]

The inoculation of Epichloë endophytes into modern cereals, resulting in systemic infection, depends on the genetics of both the host and the endophyte strain deployed. Until very recently, the only modern cereal to have been infected with Epichloë, in which normal phenotype seed-transmitted associations were achieved, is rye (Secale cereale). Whilst minor in-roads have been achieved in infecting hexaploid wheat (Triticum aestivum), the phenotypes of these associations have all been extremely poor, including host death and stunting. To identify host genetic factors that may impact the compatibility of Epichloë infection in wheat, wheat–alien chromosome addition/substitution lines were inoculated with Epichloë, and the phenotypes of infected plants were assessed. Symbioses were identified whereby infected wheat plants were phenotypically like uninfected controls. These plants completed their full lifecycle, including the vertical transmission of Epichloë into the next generation of grain, and represent the first ever compatible wheat–Epichloë associations to be created. [ABSTRACT FROM AUTHOR]

Leaf senescence is an essential physiological process related to grain yield potential and nutritional quality. Green leaf duration (GLD) after anthesis directly reflects the leaf senescence process and exhibits large genotypic differences in common wheat; however, the underlying gene regulatory mechanism is still lacking. Here, we identified TaNAM‐A1 as the causal gene of the major loci qGLD‐6A for GLD during grain filling by map‐based cloning. Transgenic assays and TILLING mutant analyses demonstrated that TaNAM‐A1 played a critical role in regulating leaf senescence, and also affected spike length and grain size. Furthermore, the functional divergences among the three haplotypes of TaNAM‐A1 were systematically evaluated. Wheat varieties with TaNAM‐A1d (containing two mutations in the coding DNA sequence of TaNAM‐A1) exhibited a longer GLD and superior yield‐related traits compared to those with the wild type TaNAM‐A1a. All three haplotypes were functional in activating the expression of genes involved in macromolecule degradation and mineral nutrient remobilization, with TaNAM‐A1a showing the strongest activity and TaNAM‐A1d the weakest. TaNAM‐A1 also modulated the expression of the senescence‐related transcription factors TaNAC‐S‐7A and TaNAC016‐3A. TaNAC016‐3A enhanced the transcriptional activation ability of TaNAM‐A1a by protein–protein interaction, thereby promoting the senescence process. Our study offers new insights into the fine‐tuning of the leaf functional period and grain yield formation for wheat breeding under various geographical climatic conditions. [ABSTRACT FROM AUTHOR]

The physicochemical properties of grains and their whole grains flour from selected newly released cultivars of wheat (Triticum aestivum) were investigated to assess their suitability for cookie making. The whole wheat flour-based cookies were examined for their physicochemical and textural properties. The relationship of flour properties with quality characteristics of cookies was evaluated through Pearson correlation and principal component analysis. The protein content showed a highly significant positive correlation with grain hardness index (GHI) (r = 0.889, p < 0.01). This showed that cultivars with higher protein content had high GHI. A highly significant positive correlation was noted between GHI and damaged starch (DS). Spread ratio (SR) of cookies showed a negative correlation with water absorption capacity and DS content of wheat flour. The SR was negatively correlated with lactic acid, sodium carbonate and water retention capacities and protein content of flour. On the basis of spread ratio and fracture strength, PBW752, DBW187, H1620 and H1612 wheat cultivars could be recommended more suitable for the preparation of whole wheat flour cookies. [ABSTRACT FROM AUTHOR]

Bread wheat (Triticum aestivum L.) is the world's as well as India's second-most important cereal crop. It is an allohexaploid composed of three homeologous sub-genomes (AA, BB, and DD), which is a constraint in determining the complete genome sequence. Several transcription factors have been associated with both abiotic and biotic stress. WRKY transcription factors are among the best characterised in the context of pathogen defence mechanisms. Different members of the WRKY transcription factors have been shown to confer resistance to stress. But very little is known about the wheat WRKY transcription factors. In silico analysis of the TaWRKY45 protein was performed in the present study using several bioinformatics tools like motif scan, CD search, NetPhos, NGlycos, GRAVY, and the SWISS MODEL. The study revealed that TaWRKY45 belongs to the group III family and contains hydrophilic proteins with 19 potential phosphorylation sites. TaWRKY45 protein was found to be orthologous to rice OsWRKY45 by phylogenetic analysis. The catalytic domain was analysed by motif scan which showed that TaWRKY45 has one WRKY domain and a C2-HC zinc finger motif. TaWRKY45's structure was determined to be more stable, more constrained, more compact, and have greater potential to interact with other molecules than OsWRKY45, according to MD simulation analysis. Thus, the in silico analysis of transcription factors in this study highlights the protein function, interaction, and regulatory pathways. [ABSTRACT FROM AUTHOR]

Pleiotropy is frequently detected in agronomic traits of wheat (Triticum aestivum). A locus on chromosome 4B, QTn/Ptn/Sl/Sns/Al/Tgw/Gl/Gw.caas-4B, proved to show pleiotropic effects on tiller, spike, and grain traits using a recombinant inbred line (RIL) population of Qingxinmai × 041133. The allele from Qingxinmai increased tiller numbers, and the allele from line 041133 produced better performances of spike traits and grain traits. Another 52 QTL for the eight traits investigated were detected on 18 chromosomes, except for chromosomes 5D, 6D, and 7B. Several genes in the genomic interval of the locus on chromosome 4B were differentially expressed in crown and inflorescence samples between Qingxinmai and line 041133. The development of the KASP marker specific for the locus on chromosome 4B is useful for molecular marker-assisted selection in wheat breeding. [ABSTRACT FROM AUTHOR]

Background: Growing wheat under climate change scenarios challenges, scientists to develop drought and heat-tolerant genotypes. The adaptive traits should therefore be explored and engineered for this purpose. Thus, this study aimed to dissect surface traits and optimizing the leaf architecture to enhance water use efficiency (WUE) and grain yield. Twenty-six wheat genotypes were assessed for five novel leaf traits (NLTs: leaf prickle hairs, groove type, rolling, angle and wettability) under normal, drought and heat conditions following triplicated factorial randomized complete block design (RCBD). The data for NLTs, physiological traits (stomatal conductance, WUE, transpiration, and photosynthesis), and standard morphological and yield traits were recorded. Leaves were sampled at the stem elongation stage (Zadoks 34) to measure the leaf water content (%), contact angle, and to obtain pictures through scanning electron microscopy (SEM). The air moisture harvesting efficiency was evaluated for five selected genotypes. The ideotype concept was applied to evaluate the best-performing genotypes. Results: The correlation analysis indicated that long leaf prickle hairs (> 100 μm), short stomatal aperture and density (40–60 mm− 2), inward to spiral leaf rolling, medium leaf indentation, low contact angle hysteresis (< 10°), and cuticular wax were positively associated with WUE. This, in turn, was significantly correlated to grain yield. Thus, the genotypes (E-1) with these traits and alternate leaf wettability had maximum grain yield (502 g m− 2) and WUE supported with high photosynthesis rate, and relative water content (94 and 75% under normal and stress conditions, respectively). However, the genotype (1-hooded) with dense leaf hairs on edges but droopy leaves, spiral leaf rolling, and lighter groove, also performed better in terms of grain yield (450 g m− 2) under heat stress conditions by maintaining high photosynthesis and WUE with low stomatal conductance and transpiration rate. Conclusion: The SEM analysis verified that the density of hairs on the leaf surface and epicuticular wax contributes towards alternate wettability patterns thereby increasing the water-use efficiency and yield of the wheat plant. This study paves a way towards screening and and developing heat and drought-tolerant cultivars that are water-saving and climate-resilient. [ABSTRACT FROM AUTHOR]

This study evaluated the efficacy of phytogenic silver and zinc nanoparticles in improving heat resilience in various wheat varieties. The silver and zinc nanoparticles were synthesized using plant leaf extract and characterized using various techniques. Four wheat varieties (DBW187, Black Wheat, DBW 50, and PBW 621) were subjected to field trials. The random block design was used, and nanoparticles in different concentrations were applied at various growth stages and morphologically, and yield parameters were recorded. UV–vis spectroscopy spectral analysis showed peaks for Ag nanoparticles at 420 nm wavelength and Zn nanoparticles at 240 and 350 nm wavelength, depicting the preliminary confirmation of nanoparticle synthesis. Electron microscopic analysis (TEM and SEM) provided morphological insights and confirmed synthesis of fine-sized particle mostly in a range between 10 and 60 nm. Energy dispersive x-ray analysis confirmed the elemental composition of the synthesized nanoparticles, with Ag and Zn elements detected in their respective samples. It also confirmed the oxide nature of synthesized ZnNPs. Dynamic light scattering analysis provided size distribution profiles, indicating average sizes of approximately 61.8 nm for Ag nanoparticles and 46.5 nm for Zn nanoparticles. The concentrations of Ag and Zn nanoparticles in the samples were found to be 196.3 ppm and 115.14 ppm, respectively, through atomic absorption spectroscopic analysis. Fourier transform infrared spectroscopy analysis revealed characteristic functional groups present in the nanoparticles. The results of field experiments established that Ag nanoparticles at 75 ppm concentration exhibited the most significant enhancements in plant growth. Conversely, Zn nanoparticles at a 100 ppm concentration demonstrated the most substantial improvements in the growth and yield of heat-stressed wheat varieties. The study concludes that optimized concentrations of silver and zinc nanoparticles can effectively improve heat stress resilience in wheat. These findings are promising to enhance abiotic stress resilience in crops. [ABSTRACT FROM AUTHOR]

Wheat stripe mosaic virus (WhSMV) is the causal agent of soilborne wheat mosaic disease (SBWMD) in Brazil, which is a serious threat to wheat production in the southern part of the country. WhSMV also occurs in Paraguay and South Africa. The virus is soilborne, transmitted by Polymyxa graminis, and management strategies are mainly based on genetic resistance. Variation in the reaction (type and severity of symptoms) of cultivars has been reported depending on the region and/or year of cultivation, leading wheat breeding programmes to test their materials in several locations, which increases costs and is time‐consuming. One hypothesis is that this variation in symptoms is a result of the genetic variability of WhSMV. We assessed the genetic variability and population structure of WhSMV infecting wheat in Brazil and South Africa. In field experiments conducted in different locations in southern Brazil, a consistent reproducibility of symptoms was observed in a set of cultivars, and molecular analysis showed a low degree of genetic variability of the Brazilian viral population. The hypothesis that the variation in SBWMD symptoms in Brazil is due to genetic variability of the virus was thus rejected. Comparison of the Brazilian and South African WhSMV isolates indicated that they comprise distinct subpopulations and that the Brazilian subpopulation is more variable than the South African subpopulation. The lower genetic variability of the South African subpopulation suggests genetic stability or a recent emergence of WhSMV in that region. [ABSTRACT FROM AUTHOR]

One of the key problems of biology is how plants adapt to unfavorable conditions, such as low temperatures. A special focus is placed on finding ways to increase tolerance in important agricultural crops like wheat. Au-based nanoparticles (Au-NPs) have been employed extensively in this area in recent years. Au-NPs can be produced fast and easily using low-cost chemical reagents. When employed in microdoses, Au-NPs are often non-toxic to plants, animals, and people. In addition, Au-NPs mainly have favorable impacts on plants. In this study, we investigated the effect of Au-NP seed nanopriming (diameter 15.3 nm, Au concentration 5–50 µg mL−1) on cold tolerance, as well as some physiological, biochemical and molecular parameters, of cold-sustainable wheat (Triticum aestivum L.) genotype Zlata. The treatment with Au-NPs improved tolerance to low temperatures in control conditions and after cold hardening. Au-NPs treatment boosted the intensity of growth processes, the quantity of photosynthetic pigments, sucrose in leaves, and the expressions of encoded RuBisCo and Wcor15 genes. The potential mechanisms of Au-NPs' influence on the cold tolerance of wheat varieties were considered. [ABSTRACT FROM AUTHOR]

Salt stress has detrimental effects on wheat plants at several physiological, biochemical, and molecular levels. This stress leads to suppressed growth, reduced grain yield, and poor quality of harvested grains. However, two approaches have shown promise for improving wheat salt tolerance: using a synthetic strigolactone analog called GR24 and applying plant growth-promoting rhizobacteria (PGPR). GR24 plays a vital role in regulating plant growth and development and in defense against various stresses. Conversely, PGPR are beneficial bacteria that colonize the rhizosphere of plants and promote their growth through multiple mechanisms. In our study, we investigated the effects of salinity on the growth and yield traits of two different wheat cultivars and explored the combined role of PGPR and GR24 in mitigating the impact of salt stress. We created three different salinity levels using NaCl in pots (original, 5 dS m−1, and 10 dS m−1) and inoculated wheat seeds with a salt-tolerant Bacillus velezensis UTB96 strain. In addition, we applied 10 μM GR24 via foliar application during the pollination stage. Our observations showed that salt stress negatively affected wheat's growth, yield, and phytochemical properties compared to the control. However, both single and combined applications of PGPR and GR24 mitigated the adverse effects of salinity. The combined treatment had a more substantial impact than either alone in inducing and improving biochemical and ionic characteristics. These included decreasing Na+ content in both leaves and roots, and EL, H2O2, and MDA content in leaves while increasing K+ content in both leaves and roots, growth and yield-related traits, RWC, chlorophyll pigments, total protein, soluble sugar, starch, proline, GB, and antioxidant enzyme activity (APX, POX, and CAT) of leaves. In conclusion, integrating PGPR and GR24 can efficiently induce salt tolerance and improve plant growth under stressed conditions. This combined approach has the potential for broad applicability in supporting plant growth in the presence of salt stress. [ABSTRACT FROM AUTHOR]

Introduction: Heat stress at terminal stage of wheat is critical and leads to huge yield losses worldwide. microRNAs (miRNAs) play significant regulatory roles in gene expression associated with abiotic and biotic stress at the post-transcriptional level. Methods: In the present study, we carried out a comparative analysis of miRNAs and their targets in flag leaves as well as developing seeds of heat tolerant (RAJ3765) and heat susceptible (HUW510) wheat genotypes under heat stress and normal conditions using small RNA and degradome sequencing. Results and discussion: A total of 84 conserved miRNAs belonging to 35 miRNA families and 93 novel miRNAs were identified in the 8 libraries. Tae-miR9672a-3p, taemiR9774, tae-miR9669-5p, and tae-miR5048-5p showed the highest expression under heat stress. Tae-miR9775, tae-miR9662b-3p, tae-miR1120a, tae-miR5084, tae-miR1122a, tae-miR5085, tae-miR1118, tae-miR1130a, tae-miR9678-3p, taemiR7757-5p, tae-miR9668-5p, tae-miR5050, tae-miR9652-5p, and tae-miR9679-5p were expressed only in the tolerant genotype, indicating their role in heat tolerance. Comparison between heat-treated and control groups revealed that 146 known and 57 novel miRNAs were differentially expressed in the various tissues. Eight degradome libraries sequence identified 457 targets of the differentially expressed miRNAs. Functional analysis of the targets indicated their involvement in photosynthesis, spliceosome, biosynthesis of nucleotide sugars and protein processing in the endoplasmic reticulum, arginine and proline metabolism and endocytosis. Conclusion: This study increases the number of identified and novel miRNAs along with their roles involved in heat stress response in contrasting genotypes at two developing stages of wheat. [ABSTRACT FROM AUTHOR]

Trait-based approaches are increasingly used to understand crop yield improvement, although they have not been widely applied to anatomical traits. Little is known about the relationships between root and leaf anatomy and yield in wheat. We selected 20 genotypes that have been widely planted in Luoyang, in the major wheat-producing area of China, to explore these relationships. A field study was performed to measure the yields and yield components of the genotypes. Root and leaf samples were collected at anthesis to measure the anatomical traits relevant to carbon allocation and water transport. Yield was negatively correlated with cross-sectional root cortex area, indicating that reduced root cortical tissue and therefore reduced carbon investment have contributed to yield improvement in this region. Yield was positively correlated with root xylem area, suggesting that a higher water transport capacity has also contributed to increased yields in this study. The area of the leaf veins did not significantly correlate with yield, showing that the high-yield genotypes did not have larger veins, but they may have had a conservative water use strategy, with tight regulation of water loss from the leaves. This study demonstrates that breeding for higher yields in this region has changed wheat's anatomical traits, reducing the roots' cortical tissue and increasing the roots' xylem investment. [ABSTRACT FROM AUTHOR]

Susceptibility is defined as the disruption of host defence systems that promotes infection or limits pathogenicity. Glutathione (GSH) is a major component of defence signalling pathways that maintain redox status and is synthesised by γ-glutamyl cysteine synthetase (γ-ECS). On the other hand, lignin acts as a barrier in the primary cell wall of vascular bundles (VBs) synthesised by phenylalanine ammonia-lyase (PAL) in the intracellular system of plants. In this study, we used two inhibitors, such as L-Buthionine-sulfoximine (BSO), which irreversibly inhibits γ-ECS, and 2,4-dichlorophenoxyacetic acid (DPA), which reduces PAL activity and leads to the induction of oxidative stress in wheat (Triticum aestivum) seedlings after exposure to Fusarium oxysporum. Seedlings treated with 1 mM L-BSO and 2,4-DPA showed high levels of hydrogen peroxide (H2O2), malondialdehyde (MDA), carbonyl (CO) content, and low activity of antioxidative enzymes [superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and glutathione reductase (GR)] as compared to wild-type (WT) seedlings under F. oxysporum infection. Further, the content of reduced glutathione (RGSH), ascorbate (ASC), and lignin was decreased in BSO and DPA treated seedlings as compared to WT seedlings during Fusarium infection. Moreover, treatment with BSO and DPA significantly inhibited the relative activity of γ-ECS and PAL (P ≤ 0.001) in WT seedlings during Fusarium infection, which led to disintegrated VBs and, finally, cell death. Our results demonstrate that inhibition of γ-ECS and PAL by BSO and DPA, respectively, disrupts the defence mechanisms of wheat seedlings and induces susceptibility to F. oxysporum. [ABSTRACT FROM AUTHOR]

Background: The study focuses on the global challenge of drought stress, which significantly impedes wheat production, a cornerstone of global food security. Drought stress disrupts cellular and physiological processes in wheat, leading to substantial yield losses, especially in arid and semi-arid regions. The research investigates the use of Spirulina platensis aqueous extract (SPAE) as a biostimulant to enhance the drought resistance of two Egyptian wheat cultivars, Sakha 95 (drought-tolerant) and Shandawel 1 (drought-sensitive). Each cultivar's grains were divided into four treatments: Cont, DS, SPAE-Cont, and SPAE + DS. Cont and DS grains were presoaked in distilled water for 18 h while SPAE-Cont and SPAE + DS were presoaked in 10% SPAE, and then all treatments were cultivated for 96 days in a semi-field experiment. During the heading stage (45 days: 66 days), two drought treatments, DS and SPAE + DS, were not irrigated. In contrast, the Cont and SPAE-Cont treatments were irrigated during the entire experiment period. At the end of the heading stage, agronomy, pigment fractions, gas exchange, and carbohydrate content parameters of the flag leaf were assessed. Also, at the harvest stage, yield attributes and biochemical aspects of yielded grains (total carbohydrates and proteins) were evaluated. Results: The study demonstrated that SPAE treatments significantly enhanced the growth vigor, photosynthetic rate, and yield components of both wheat cultivars under standard and drought conditions. Specifically, SPAE treatments increased photosynthetic rate by up to 53.4%, number of spikes by 76.5%, and economic yield by 190% for the control and 153% for the drought-stressed cultivars pre-soaked in SPAE. Leaf agronomy, pigment fractions, gas exchange parameters, and carbohydrate content were positively influenced by SPAE treatments, suggesting their effectiveness in mitigating drought adverse effects, and improving wheat crop performance. Conclusion: The application of S. platensis aqueous extract appears to ameliorate the adverse effects of drought stress on wheat, enhancing the growth vigor, metabolism, and productivity of the cultivars studied. This indicates the potential of SPAE as an eco-friendly biostimulant for improving crop resilience, nutrition, and yield under various environmental challenges, thus contributing to global food security. [ABSTRACT FROM AUTHOR]

Resistance to pre-harvest sprouting (PHS) is an agronomically important trait affecting the yield and grain quality of bread wheat. PHS resistance depends both on environmental factors and the genotypic and phenotypic properties of wheat varieties. It is known that wheat varieties with red-grain are more resistant to PHS than white-grain varieties. However, at present there are no methodological approaches that allow to unambiguously distinguish red-grain varieties according to the level of PHS resistance. The purpose of the study was to compare different methods for efficient differentiation of soft winter wheat (Triticum aestivum L.) varieties for resistance to PHS. The germination index (GI), α-amylase activity (AAA), a digital grade of the grain color and genetic bases of the wheat varieties the grain was determined in 164 winter wheat, among them 156 were red-grain. The studies were carried out at the late milk/hard dough (LM/HD; GS77-GS87) stage and the hard grain (HG; GS92-GS93) stage. Based on the dynamics of GI it was found that late LM/HD stage is the most suitable for GI evaluation. AAA was performed using the Ceralpha method and falling number (FN) evaluation. An increase in the level of AAA during grain ripening of wheat varieties was shown. A negative correlation was found between GI and FN, FN and AAA. Using the Lab color model to assess the color variation of the grain coat allow to identify 3 variants of grain color. Genetic base of wheat varieties was analyzed by means of allelic composition of the Tamyb10 gene, which participate in the formation of the red color of grain. The results indicated that digital analysis and allelic composition of the Tamyb10 cannot be used as additional criterion for separation of red-grain wheat varieties for resistance to PHS. This is despite the fact that the numerous group of the varieties contain two or more dominant Tamyb10 gene. In general, a comparison of varieties by all three parameters allow to identify a group of varieties that are most PHS resistant. This group consist of 73 red-grain varieties out of 156, while no white-grain PHS-resistant varieties were identified. [ABSTRACT FROM AUTHOR]

Jasmonates are involved in the regulation of protective mechanisms of plants against unfavorable environments as well as in control of their growth and development. Main data on jasmonate biosynthesis and signals transduction pathways were obtained on model dicotyledonous plant Arabidopsis thaliana. Meanwhile, functions and molecular mode of action of these compounds are still poorly investigated in monocotyledons, including wheat. In the present study, the stress tolerance of transgenic line (Tr-3) and nontransgenic plants of bread wheat cv. Saratovskaya-60 was studied. Transgenic line Tr-3 overexpresses AtOPR3 (12-OXOPHYTODIENOATE REDUCTASE 3) gene from A. thaliana encoding the jasmonate biosynthesis enzyme 12-oxophytodienoate reductase. In spite of the high expression level of AtOPR3, the content of jasmonic acid and its conjugate with isoleucine in intact leaves of the transgenic plants remained unchanged. Furthermore, in the mechanically wounded leaves, the content of jasmonic acid in the transgenic line Tr-3 was even lower than in nontransgenic Saratovskaya-60, while the levels of 12-oxophytodienoic acid and jasmonoil-isoleucine did not differ. In the transgenic plants, the stress-induced expression of the endogenous jasmotate-regulated allene oxide synthase gene was, however, higher than in the nontransgenic control. The transgenic wheat plants were more tolerant to infection by necrotrophic fungus Botrytis cinerea and to osmotic stress caused by polyethylene glycol applied to germinating seeds. The Botrytis-inoculated leaves of the transgenic line Tr-3 manifested higher activity of antioxidant enzyme catalase than inoculated leaves of nontransgenic plants. This fact points to the possible role of catalase in the transgene-associated tolerance to the pathogen. Therefore, the available scarce information concerning the peculiarities of functions of the jasmonate system in wheat plants has been amended with the new data on the role of expression of one of the key genes of jasmonate biosynthesis, namely, 12-OXOPHYTODIENOATE REDUCTASE, in control of defense responses even though the stress-induced level of jasmonic acid is decreased. [ABSTRACT FROM AUTHOR]

The effect of ultrasound (5, 10, and 20 min, intensity 25 kW/m2, frequency 26.1 kHz) on the dynamics of the activity of the main antioxidant enzymes, superoxide dismutase, catalase, peroxidase, and the expression of the genes encoding them (SOD-1, CAT, POD), was studied in germinating seeds and wheat sprouts. Ultrasound after one hour predominantly suppressed the activity of antioxidant enzymes, with subsequent restoration and increase (after one and six days) of activity. The content of mRNA transcripts of the studied genes predominantly increased one hour after exposure, and subsequently (after one and six days) it was either higher or remained equal to the control. The results obtained apparently indicate that ultrasound triggers eustress mechanisms; i.e., the stimulating effect led to the mobilization of protective processes of cells, hormesis. [ABSTRACT FROM AUTHOR]

Wheat (Triticum aestivum L.) is an essential food crop in terms of consumption as well as production. Aflatoxin exposure has a widespread public health impact in economically developing nations, so there is a need to establish preventive techniques for these high-risk populations. Pre-harvest and post-harvest practices are the two strategies used to control aflatoxin contamination, which include the use of genetically modified crops that show resistance against Aspergillus infection, the use of pesticides, changing the planting and harvesting time of crops, and physical, chemical, and biological methods. In this research, aflatoxin detection and quantification were performed in different wheat varieties to determine quantitative differences in comparison to the European Commission's limit of 4 ppb aflatoxins in wheat. TLC for qualitative and the ELISA kit method for quantitative analysis of aflatoxins were used. Out of 56 samples, 35 were found contaminated with aflatoxins, while the remaining 21 samples did not show any presence of aflatoxins. Out of the 35 contaminated samples, 20 samples showed aflatoxin contamination within the permissible limit, while the remaining 15 samples showed aflatoxin concentration beyond the permissible level, ranging from 0.49 to 20.56 ppb. After quantification, the nine highly contaminated wheat samples were detoxified using physical, chemical, and biological methods. The efficiency of these methods was assessed, and they showed a significant reduction in aflatoxins of 53–72%, 79–88%, and 80–88%, respectively. In conclusion, the difference in aflatoxin concentration in different wheat varieties could be due to genetic variations. Furthermore, biological treatment could be the method of choice for detoxification of aflatoxins in wheat as it greatly reduced the aflatoxin concentration with no harmful effect on the quality of the grains. [ABSTRACT FROM AUTHOR]

SNF1-related protein kinase 2 (SnRK2) family members are essential components of the plant abscisic acid (ABA) signaling pathway initiated by osmotic stress and triggering a drought stress response. This study characterized the molecular properties of TaSnRK2.4 and its function in mediating adaptation to drought in Triticum aestivum. Transcripts of TaSnRK2.4 were upregulated upon drought and ABA signaling and associated with drought- and ABA-responsive cis-elements ABRE and DRE, and MYB and MYC binding sites in the promoter as indicated by reporter GUS protein staining and activity driven by truncations of the promoter. Yeast two-hybrid, BiFC, and Co-IP assays indicated that TaSnRK2.4 protein interacts with TaPP2C01 and an ABF transcription factor (TF) TaABF2. The results suggested that TaSnRK2.4 forms a functional TaPP2C01-TaSnRK2.4-TaABF2 module with its upstream and downstream partners. Transgene analysis revealed that TaSnRK2.4 and TaABF2 positively regulate drought tolerance whereas TaPP2C01 acts negatively by modulating stomatal movement, osmotic adjustment, reactive oxygen species (ROS) homeostasis, and root morphology. Expression analysis, yeast one-hybrid, and transcriptional activation assays indicated that several osmotic stress-responsive genes, including TaSLAC1-4, TaP5CS3, TaSOD5, TaCAT1, and TaPIN4, are regulated by TaABF2. Transgene analysis verified their functions in positively regulating stomatal movement (TaSLAC1-4), proline accumulation (TaP5CS3), SOD activity (TaSOD5), CAT activity (TaCAT1), and root morphology (TaPIN4). There were high correlations between plant biomass and yield with module transcripts in a wheat variety panel cultivated under drought conditions in the field. Our findings provide insights into understanding plant drought response underlying the SnRK2 signaling pathway in common wheat. [ABSTRACT FROM AUTHOR]

The study of cold-tolerance mechanisms of wheat as a leading cereal crop is very relevant to science. Primary metabolites play an important role in the formation of increased cold tolerance. The aim of this research is to define changes in the content of primary metabolites (soluble proteins and sugars), growth, and photosynthetic apparatus of freezing-tolerant and cold-sustainable wheat (Triticum aestivum L.) genotypes under optimal conditions and after prolonged (7 days) exposure to low temperature (4 °C). In order to gain a deeper comprehension of the mechanisms behind wheat genotypes' adaptation to cold, we determined the expression levels of photosynthetic genes (RbcS, RbcL) and genes encoding cold-regulated proteins (Wcor726, CBF14). The results indicated different cold-adaptation strategies of freezing-tolerant and cold-sustainable wheat genotypes, with soluble proteins and sugars playing a significant role in this process. In plants of freezing-tolerant genotypes, the strategy of adaptation to low temperature was aimed at increasing the content of soluble proteins and modification of carbohydrate metabolism. The accumulation of sugars was not observed in wheat of cold-sustainable genotypes during chilling, but a high content of soluble proteins was maintained both under optimal conditions and after cold exposure. The adaptation strategies of wheat genotypes differing in cold tolerance were related to the expression of photosynthetic genes and genes encoding cold-regulated proteins. The data improve our knowledge of physiological and biochemical mechanisms of wheat cold adaptation. [ABSTRACT FROM AUTHOR]

Abstract Efficient use of nitrogen (N) and phosphorus (P) is essential to reduce fertilizer costs and nutrient pollution and to lower the carbon footprint of agriculture. This requires a better understanding of N and P limitations on photosynthesis and biomass generation in one of the world's most important crops, wheat (Triticum aestivum). In a fully factorial nutrient experiment, we find that the limiting nutrient, N or P, at a Redfield‐like N:P ratio (21N:1P molar) produces the ‘effective dose of fertilizer’ for the generation of above‐ground biomass (seed or vegetative). Best‐fit structural equation models showed that neither N nor P applied in excess of 21N:1P led to any increase in biomass. The light (qP, NPQ) and dark (Amax, Vcmax, Jmax) reactions of photosynthesis are also constrained by the limiting nutrient at the 21N:1P Redfield‐like ratio. Beyond this ratio, ‘excess N’ or ‘excess P’ had no effects. The direct effects of the ‘effective dose of fertilizer’ on the accumulation of biomass were stronger than its indirect effects via photosynthesis, likely driven by the N and P costs in building nucleic acids needed for cell division, cell maintenance and RNA transcription. Modern composite fertilizers are typically provided at a much higher P content than a 21N:1P ratio, potentially resulting in a huge global wastage of P, a finite resource, with all the concomitant costs to the farmer, consumer and the environment.

One of the major challenges that plant breeders face in the 21st century is food safety for growing human population coupled with extreme climate changes. Accordingly, the most important breeders' goal is to find appropriate methods in response to these challenges in order to create high-yielding varieties resilient to abiotic and biotic stressors. The aim of this study was to determine optimal doses of gamma irradiation in two wheat and one barley varieties and to apply the identified doses for development of mutant populations. Wheat and barley varieties showed different reactions to applied doses of gamma irradiation. Wheat varieties had germination rate over 90% at all applied doses while barley seeds showed to be more susceptible to gamma irradiation. Gamma irradiation had greater influence on seedling height which was clearly demonstrated by growth reduction with increasing radiation doses. ANOVA showed a significant difference between genotypes, applied doses of gamma radiation as well as genotype by doses interaction for seedling height. At highest dose of 600 Gy, the reduction of seedling height was 94.6%, 96.5% and 96.8% in Simonida, Rudnik and NS 40S, respectively. The irradiation doses that resulted in seedling growth reduction by 50% (GR50) were 210 Gy for barley Rudnik and wheat NS 40S, and 310 Gy for wheat variety Simonida. Identified doses were used for the irradiation of 2000 seeds of each variety in order to produce mutant populations that will be further used in a breeding program for development of varieties with increased resilience to climate change.

Summary: Wheat needs different durations of vernalization, which accelerates flowering by exposure to cold temperature, to ensure reproductive development at the optimum time, as that is critical for adaptability and high yield. TaVRN1 is the central flowering regulator in the vernalization pathway and encodes a MADS‐box transcription factor (TF) that usually works by forming hetero‐ or homo‐dimers. We previously identified that TaVRN1 bound to an MADS‐box TF TaSOC1 whose orthologues are flowering activators in other plants. The specific function of TaSOC1 and the biological implication of its interaction with TaVRN1 remained unknown. Here, we demonstrated that TaSOC1 was a flowering repressor in the vernalization and photoperiod pathways by overexpression and knockout assays. We confirmed the physical interaction between TaSOC1 and TaVRN1 in wheat protoplasts and in planta, and further validated their genetic interplay. A Flowering Promoting Factor 1‐like gene TaFPF1‐2B was identified as a common downstream target of TaSOC1 and TaVRN1 through transcriptome and chromatin immunoprecipitation analyses. TaSOC1 competed with TaVRT2, another MADS‐box flowering regulator, to bind to TaVRN1; their coding genes synergistically control TaFPF1‐2B expression and flowering initiation in response to photoperiod and low temperature. We identified major haplotypes of TaSOC1 and found that TaSOC1‐Hap1 conferred earlier flowering than TaSOC1‐Hap2 and had been subjected to positive selection in wheat breeding. We also revealed that wheat SOC1 family members were important domestication loci and expanded by tandem and segmental duplication events. These findings offer new insights into the regulatory mechanism underlying flowering control along with useful genetic resources for wheat improvement. [ABSTRACT FROM AUTHOR]

Stripe rust is a devastating disease of wheat worldwide. Chinese wheat cultivar Lanhangxuan 121 (LHX121), selected from an advanced line L92-47 population that had been subjected to space mutation breeding displayed a consistently higher level of resistance to stipe rust than its parent in multiple field environments. The aim of this research was to establish the number and types of resistance genes in parental lines L92-47 and LHX121 using separate segregating populations. The first population developed from a cross between LHX121 and susceptible cultivar Xinong 822 comprised 278 F2:3 lines. The second validation population comprised 301 F2:3 lines from a cross between L92-47 and susceptible cultivar Xinong 979. Lines of two population were evaluated for stripe rust response at three sites during the 2018–2020 cropping season. Affymetrix 660 K SNP arrays were used to genotype the lines and parents. Inclusive composite interval mapping detected QTL QYrLHX.nwafu-2BS, QYrLHX.nwafu-3BS, and QYrLHX.nwafu-5BS for resistance in all three environments. Based on previous studies and pedigree information, QYrLHX.nwafu-2BS and QYrLHX.nwafu-3BS were likely to be Yr27 and Yr30 that are present in the L92-47 parent. QYrLHX.nwafu-5BS (YrL121) detected only in LHX121 was mapped to a 7.60 cM interval and explained 10.67–22.57% of the phenotypic variation. Compared to stripe rust resistance genes previously mapped to chromosome 5B, YrL121 might be a new adult plant resistance QTL. Furthermore, there were a number of variations signals using 35 K SNP array and differentially expressed genes using RNA-seq between L92-47 and LHX121 in the YrL121 region, indicating that they probably impair the presence and/or function of YrL121. [ABSTRACT FROM AUTHOR]

Plant-growth-promoting bacteria are an important economic and environmental resource as biofertilizers that can stimulate plant growth and improve agricultural yields. In this study, potential plant growth-promoting bacteria were isolated from soil samples collected in Russia. Strains that manifested active growth on a nitrogen-free medium, the Pikovskaya medium (with insoluble phosphates) and CAS (Chrome Azurol S) agar, were selected for the study. All bacterial isolates were identified by 16S rRNA gene sequencing analysis. Seventeen bacterial isolates of different species were purified and quantified for their ability to grow on nitrogen-free media; dissolve phosphate; and produce ammonium, indole-3-acetic acid, siderophores, and antifungal activity. Principal component analysis identified three groups of strains: one with the maximum signs of providing "plant nutrition"; one with signs of "antimicrobial activity"; and a group "without outstanding signs". All 17 strains were involved in experiments involving growing inoculated wheat seeds (Triticum aestivum) in pots under natural environmental conditions, and were assessed by their effect on the wheat growth and yield as well as on the chemical composition of the soil. For the "plant nutrition" group, regression analysis revealed a connection between indicators of plant growth, ear length, and ammonium accumulation in the soil. However, in other groups, there were also strains showing a positive effect on plant growth, which suggests the necessity of involving additional factors to predict the ability of strains to affect plants when screened in the laboratory. [ABSTRACT FROM AUTHOR]

Cultivating wheat (Triticum aestivum) in a closed environment offers applications in both indoor farming and in outer-space farming. Tailoring the photoperiod holds potential to shorten the growth cycle, thereby increasing the annual number of cycles. As wheat is a long-day plant, a night shorter than a critical length is required to induce flowering. In growth chambers, experiments were conducted to examine the impact of a 6 h light–dark cycle on the timing of wheat ear emergence, grain yield, and flour quality. Under equal daily light-integral conditions, the 6 h light–dark cycle promoted growth and development, resulting in accelerated ear emergence when compared to a 12 h cycle, additionally indicating that 12 h of darkness was excessive. To further stimulate heading and increase yield, the 6 h cycle was changed at the onset of stem elongation to a 14 h–10 h, mimicking spring conditions, and maintained until maturity. This successful transition was then combined with two levels of light intensity and nutrient solution, which did not significantly impact yield, while tillering and grain ripening did increase under higher light intensities. Moreover, it enabled manipulation of the baking quality, although lower-end falling numbers were observed. In conclusion, combining a 6 h light–dark cycle until stem elongation with a 14 h–10 h cycle presents a promising strategy for increasing future wheat production in closed environments. The observation of low falling numbers underscores the importance of factoring in flour quality when designing the wheat-growing systems of the future. [ABSTRACT FROM AUTHOR]

Background: Wheat (Triticum aestivum L.) is one of the most widely grown and vital cereal crops, containing a high percentage of basic nutrients such as carbohydrates and proteins. Drought stress is one of the most significant limitations on wheat productivity. Due to climate change influences plant development and growth, physiological processes, grain quality, and yield. Drought stress has elicited a wide range of plant responses, namely physiological and molecular adaptations. Biopriming is one of the recent attempts to combat drought stress. Mitigating the harmful impact of abiotic stresses on crops by deploying extreme-habitat-adapted symbiotic microbes. The purpose of this study was to see how biopriming Triticum aestivum grains affected the effects of inoculating endophytic fungi Aspergillus fumigatus ON307213 isolated from stressed wheat plants in four model agricultural plants (Gemmiza-7, Sids-1, Sakha8, and Giza 168). And its viability in reducing drought stress through the use of phenotypic parameters such as root and shoot fresh and dry weight, shoot and root length, and so on. On a biochemical and physiological level, enzymatic parameters such as catalase and superoxidase dismutase are used. Total phenolics, flavonoids, and photosynthetic pigments are non-enzymatic parameters. Making use of molecular techniques such as reverse transcriptase polymerase chain reaction (RT-PCR). Results: It has been found that using Aspergillus fumigatus as a biological biopriming tool can positively impact wheat plants experiencing drought stress. The total biomass of stressed wheat plants that had been bio-primed rose by more than 40% as compared to wheat plants that had not been bio-primed. A. fumigatus biopriming either increased or decreased the amount of enzymatic and non-enzymatic substances on biochemical scales, aside from the noticeable increase in photosynthetic pigment that occurs in plants that have been bio-primed and stressed. Drought-resistant genes show a biopriming influence in gene expression. Conclusions: This is the first paper to describe the practicality of a. fumigatus biopriming and its effect on minimizing the degrading effects of drought through water limitation. It suggests the potential applications of arid habitat-adapted endophytes in agricultural systems. [ABSTRACT FROM AUTHOR]