Innovative computational tools provide new insights into the polyploid wheat genome.

Bread wheat (Triticum aestivum) is an important crop and serves as a significant source of protein and calories for humans, worldwide. Nevertheless, its large and allopolyploid genome poses constraints on genetic improvement. The complex reticulate evolutionary history and the intricacy of genomic resources make the deciphering of the functional genome considerably more challenging. Recently, we have developed a comprehensive list of versatile computational tools with the integration of statistical models for dissecting the polyploid wheat genome. Here, we summarize the methodological innovations and applications of these tools and databases. A series of step-by-step examples illustrates how these tools can be utilized for dissecting wheat germplasm resources and unveiling functional genes associated with important agronomic traits. Furthermore, we outline future perspectives on new advanced tools and databases, taking into consideration the unique features of bread wheat, to accelerate genomic-assisted wheat breeding.

The potassium transporter TaNHX2 interacts with TaGAD1 to promote drought tolerance via modulating stomatal aperture in wheat.

Drought is a major global challenge in agriculture that decreases crop production. γ-Aminobutyric acid (GABA) interfaces with drought stress in plants; however, a mechanistic understanding of the interaction between GABA accumulation and drought response remains to be established. Here we showed the potassium/proton exchanger TaNHX2 functions as a positive regulator in drought resistance in wheat by mediating cross-talk between the stomatal aperture and GABA accumulation. TaNHX2 interacted with glutamate decarboxylase TaGAD1, a key enzyme that synthesizes GABA from glutamate. Furthermore, TaNHX2 targeted the C-terminal auto-inhibitory domain of TaGAD1, enhanced its activity, and promoted GABA accumulation under drought stress. Consistent with this, the tanhx2 and tagad1 mutants showed reduced drought tolerance, and transgenic wheat with enhanced TaNHX2 expression had a yield advantage under water deficit without growth penalty. These results shed light on the plant stomatal movement mechanism under drought stress and the TaNHX2-TaGAD1 module may be harnessed for amelioration of negative environmental effects in wheat as well as other crops.

Positional cloning and characterization reveal the role of TaSRN-3D and TaBSR1 in the regulation of seminal root number in wheat.

Seminal roots play a critical role in water and nutrient absorption, particularly in the early developmental stages of wheat. However, the genes responsible for controlling SRN in wheat remain largely unknown. Genetic mapping and functional analyses identified a candidate gene (TraesCS3D01G137200, TaSRN-3D) encoding a Ser/Thr kinase glycogen synthase kinase 3 (STKc_GSK3) that regulated SRN in wheat. Additionally, experiments involving hormone treatment, nitrate absorption and protein interaction were conducted to explore the regulatory mechanism of TaSRN-3D. Results showed that the TaSRN-3D4332 allele inhibited seminal roots initiation and development, while loss-of-function mutants showed significantly higher seminal root number (SRN). Exogenous application of epi-brassinolide could increase the SRN in a HS2-allelic background. Furthermore, chlorate sensitivity and 15N uptake assays revealed that a higher number of seminal roots promoted nitrate accumulation. TaBSR1 (BIN2-related SRN Regulator 1, orthologous to OsGRF4/GL2 in rice) acts as an interactor of TaSRN-3D and promotes TaBSR1 degradation to reduce SRN. This study provides valuable insights into understanding the genetic basis and regulatory network of SRN in wheat, highlighting their roles as potential targets for root-based improvement in wheat breeding.

Natural variation of STKc_GSK3 kinase TaSG-D1 contributes to heat stress tolerance in Indian dwarf wheat.

Heat stress threatens global wheat (Triticum aestivum) production, causing dramatic yield losses worldwide. Identifying heat tolerance genes and comprehending molecular mechanisms are essential. Here, we identify a heat tolerance gene, TaSG-D1E286K, in Indian dwarf wheat (Triticum sphaerococcum), which encodes an STKc_GSK3 kinase. TaSG-D1E286K improves heat tolerance compared to TaSG-D1 by enhancing phosphorylation and stability of downstream target TaPIF4 under heat stress condition. Additionally, we reveal evolutionary footprints of TaPIF4 during wheat selective breeding in China, that is, InDels predominantly occur in the TaPIF4 promoter of Chinese modern wheat cultivars and result in decreased expression level of TaPIF4 in response to heat stress. These sequence variations with negative effect on heat tolerance are mainly introduced from European germplasm. Our study provides insight into heat stress response mechanisms and proposes a potential strategy to improve wheat heat tolerance in future.

Satellite Video Multi-Label Scene Classification With Spatial and Temporal Feature Cooperative Encoding: A Benchmark Dataset and Method.

Satellite video multi-label scene classification predicts semantic labels of multiple ground contents to describe a given satellite observation video, which plays an important role in applications like ocean observation, smart cities, et al. However, the lack of a high-quality and large-scale dataset prevents further improvement of the task. And existing methods on general videos have the difficulty to represent the local details of ground contents when directly applied to the satellite videos. In this paper, our contributions include (1) we develop the first publicly available and large-scale satellite video multi-label scene classification dataset. It consists of 18 classes of static and dynamic ground contents, 3549 videos, and 141960 frames. (2) we propose a baseline method with the novel Spatial and Temporal Feature Cooperative Encoding (STFCE). It exploits the relations between local spatial and temporal features, and models long-term motion information hidden in inter-frame variations. In this way, it can enhance features of local details and obtain the powerful video-scene-level feature representation, which raises the classification performance effectively. Experimental results show that our proposed STFCE outperforms 13 state-of-the-art methods with a global average precision (GAP) of 0.8106 and the careful fusion and joint learning of the spatial, temporal, and motion features are beneficial to achieve a more robust and accurate model. Moreover, benchmarking results show that the proposed dataset is very challenging and we hope it could promote further development of the satellite video multi-label scene classification task.

Methyltransferase TaSAMT1 mediates wheat freezing tolerance by integrating brassinosteroid and salicylic acid signaling.

Cold injury is a major environmental stress affecting the growth and yield of crops. Brassinosteroids (BRs) and salicylic acid (SA) play important roles in plant cold tolerance. However, whether or how BR signaling interacts with the SA signaling pathway in response to cold stress is still unknown. Here, we identified an SA methyltransferase, TaSAMT1, that converts SA to methyl SA (MeSA) and confers freezing tolerance in wheat (Triticum aestivum). TaSAMT1 overexpression greatly enhanced wheat freezing tolerance, with plants accumulating more MeSA and less SA, whereas Tasamt1 knockout lines were sensitive to freezing stress and accumulated less MeSA and more SA. Spraying plants with MeSA conferred freezing tolerance to Tasamt1 mutants, but SA did not. We revealed that BRASSINAZOLE-RESISTANT 1 (TaBZR1) directly binds to the TaSAMT1 promoter and induces its transcription. Moreover, TaBZR1 interacts with the histone acetyltransferase TaHAG1, which potentiates TaSAMT1 expression via increased histone acetylation and modulates the SA pathway during freezing stress. Additionally, overexpression of TaBZR1 or TaHAG1 altered TaSAMT1 expression and improved freezing tolerance. Our results demonstrate a key regulatory node that connects the BR and SA pathways in the plant cold stress response. The regulatory factors or genes identified could be effective targets for the genetic improvement of freezing tolerance in crops.

Genomic insights into the origin and evolution of spelt (Triticum spelta L.) as a valuable gene pool for modern wheat breeding.

Spelt (Triticum aestivum ssp. spelta) is an important wheat subspecies mainly cultivated in Europe before the 20th century that has contributed to modern wheat breeding as a valuable genetic resource. However, relatively little is known about the origins and maintenance of spelt populations. Here, using resequencing data from 416 worldwide wheat accessions, including representative spelt wheat, we demonstrate that European spelt emerged when primitive hexaploid wheat spread to the west and hybridized with pre-settled domesticated emmer, the putative maternal donor. Genomic introgression regions from domesticated emmer confer spelt's primitive morphological characters used for species taxonomy, such as tenacious glumes and later flowering. We propose a haplotype-based "spelt index" to identify spelt-type wheat varieties and to quantify utilization of the spelt gene pool in modern wheat cultivars. This study reveals the genetic basis for the establishment of the spelt wheat subspecies in a specific ecological niche and the vital role of the spelt gene pool as a unique germplasm resource in modern wheat breeding.

Reshaped DNA methylation cooperating with homoeolog-divergent expression promotes improved root traits in synthesized tetraploid wheat.

Polyploidization is a major event driving plant evolution and domestication. However, how reshaped epigenetic modifications coordinate gene transcription to generate phenotypic variations during wheat polyploidization is currently elusive. Here, we profiled transcriptomes and DNA methylomes of two diploid wheat accessions (SlSl and AA) and their synthetic allotetraploid wheat line (SlSlAA), which displayed elongated root hair and improved root capability for nitrate uptake and assimilation after tetraploidization. Globally decreased DNA methylation levels with a reduced difference between subgenomes were observed in the roots of SlSlAA. DNA methylation changes in first exon showed strong connections with altered transcription during tetraploidization. Homoeolog-specific transcription was associated with biased DNA methylation as shaped by homoeologous sequence variation. The hypomethylated promoters showed significantly enriched binding sites for MYB, which may affect gene transcription in response to root hair growth. Two master regulators in root hair elongation pathway, AlCPC and TuRSL4, exhibited upregulated transcription levels accompanied by hypomethylation in promoter, which may contribute to the elongated root hair. The upregulated nitrate transporter genes, including NPFs and NRTs, also are significantly associated with hypomethylation, indicating an epigenetic-incorporated regulation manner in improving nitrogen use efficiency. Collectively, these results provided new insights into epigenetic changes in response to crop polyploidization and underscored the importance of epigenetic regulation in improving crop traits.

Evaluation of bidirectional relationships between risk preference and mood disorders: A 2-sample Mendelian randomization study.

BACKGROUND: Risk preference is often defined as the tendency to engage in risky activities. Increasing evidence shows that risk preference is associated with mood disorders. However, the causality and direction of this association are not clear. METHODS: Genome-wide association study summary data of risk preference in 939,908 participants from UK Biobank and 23andMe were used to identify general risk preference. Data for 413,466 individuals taken from The Psychiatric Genomics Consortium were used to identify bipolar disorder (BP). Data for 807,553 individuals taken from The Psychiatric Genomics Consortium were used to identify major depressive disorder (MDD). The weighted median, inverse-variance weighting, and Mendelian randomization-Egger methods were used for the Mendelian randomization analysis to estimate a causal effect and detect directional pleiotropy. RESULTS: GWAS summary data were obtained from three combined samples, containing 939,908, 413,466 and 807,553 individuals of European ancestry. Mendelian randomization evidence suggested that risk preference increased the onset of BP, and BP also increased risk preference (P < 0.001). In contrast, there were no reliable results to describe the relationship of risk preference with MDD (P > 0.05). Furthermore, there was no significant relationship between MDD and risk preference. CONCLUSION: Using large-scale GWAS data, robust evidence supports a mutual relationship between risk preference and BP, but no relationship between risk preference and MDD was observed. This study indicates a potential marker for the early identification of MDD and BP. Additionally, it shows that reducing risk preferences for patients with BP may be a valuable intervention for treating BP.

High-Yield Synthesis of Phosphatidylserine in a Well-Designed Mixed Micellar System.

A sustainable enzymatic system is essential for efficient phosphatidylserine (PS) synthesis in industrial production. Conventional biphasic systems face challenges such as excessive organic solvent usage, enzyme-intensive processes, and increased costs. This study introduces a novel approach using chitin nanofibrils (ChNFs) as an immobilization material for phospholipase D (PLD) in a mixed micellar system stabilized by the food-grade emulsifier sodium deoxycholate (SDC). The immobilized enzyme, ChNF-chiA1, was quickly prepared in a one-step process, eliminating the need for purification. By optimizing the reaction conditions, including l-Ser concentration (1.0 M), SDC concentration (10 mM), reaction time (8 h), and enzyme dosage (1.0 U), a remarkable PS yield of 96.74% was achieved in the solvent-free mixed micellar system. The catalytic efficiency of ChNF-chiA1 surpassed that of the free PLD-chiA1 biphasic system by 6.0-fold. This innovative and green biocatalytic technology offers a reusable solution for the high-value enzymatic synthesis of phospholipids, providing a promising avenue for industrial applications.

Type I MADS-box transcription factor TaMADS-GS regulates grain size by stabilizing cytokinin signalling during endosperm cellularization in wheat.

Grain size is one of the important traits in wheat breeding programs aimed at improving yield, and cytokinins, mainly involved in cell division, have a positive impact on grain size. Here, we identified a novel wheat gene TaMADS-GS encoding type I MADS-box transcription factor, which regulates the cytokinins signalling pathway during early stages of grain development to modulate grain size and weight in wheat. TaMADS-GS is exclusively expressed in grains at early stage of seed development and its knockout leads to delayed endosperm cellularization, smaller grain size and lower grain weight. TaMADS-GS protein interacts with the Polycomb Repressive Complex 2 (PRC2) and leads to repression of genes encoding cytokinin oxidase/dehydrogenases (CKXs) stimulating cytokinins inactivation by mediating accumulation of the histone H3 trimethylation at lysine 27 (H3K27me3). Through the screening of a large wheat germplasm collection, an elite allele of the TaMADS-GS exhibits higher ability to repress expression of genes inactivating cytokinins and a positive correlation with grain size and weight, thus representing a novel marker for breeding programs in wheat. Overall, these findings support the relevance of TaMADS-GS as a key regulator of wheat grain size and weight.

HEMU: An integrated comparative genomics database and analysis platform for Andropogoneae grasses.

This study reports an online database and analysis platform HEMU, which integrates 75 genome assemblies from 20 unique species, large amounts of multi-omics data, and six sophisticated analysis toolkits. HEMU will facilitate comparative genomics analysis within the tribe Andropogoneae.

Mutation of a highly conserved amino acid in RPM1 causes leaf yellowing and premature senescence in wheat.

KEY MESSAGE: A point mutation of RPM1 triggers persistent immune response that induces leaf premature senescence in wheat, providing novel information of immune responses and leaf senescence. Leaf premature senescence in wheat (Triticum aestivum L.) is one of the most common factors affecting the plant's development and yield. In this study, we identified a novel wheat mutant, yellow leaf and premature senescence (ylp), which exhibits yellow leaves and premature senescence at the heading and flowering stages. Consistent with the yellow leaves phenotype, ylp had damaged and collapsed chloroplasts. Map-based cloning revealed that the phenotype of ylp was caused by a point mutation from Arg to His at amino acid 790 in a plasma membrane-localized protein resistance to Pseudomonas syringae pv. maculicola 1 (RPM1). The point mutation triggered excessive immune responses and the upregulation of senescence- and autophagy-associated genes. This work provided the information for understanding the molecular regulatory mechanism of leaf senescence, and the results would be important to analyze which mutations of RPM1 could enable plants to obtain immune activation without negative effects on plant growth.

TaACTIN7-D regulates plant height and grain shape in bread wheat.

Exploitation of new gene resources and genetic networks contributing to the control of crop yield-related traits, such as plant height, grain size, and shape, may enable us to breed modern high-yielding wheat varieties through molecular methods. In this study, via ethylmethanesulfonate mutagenesis, we identify a wheat mutant plant, mu-597, that shows semi-dwarf plant architecture and round grain shape. Through bulked segregant RNA-seq and map-based cloning, the causal gene for the semi-dwarf phenotype of mu-597 is located. We find that a single-base mutation in the coding region of TaACTIN7-D (TaACT7-D), leading to a Gly-to-Ser (G65S) amino acid mutation at the 65th residue of the deduced TaACT7-D protein, can explain the semi-dwarfism and round grain shape of mu-597. Further evidence shows that the G65S mutation in TaACT7-D hinders the polymerization of actin from monomeric (G-actin) to filamentous (F-actin) status while attenuates wheat responses to multiple phytohormones, including brassinosteroids, auxin, and gibberellin. Together, these findings not only define a new semi-dwarfing gene resource that can be potentially used to design plant height and grain shape of bread wheat but also establish a direct link between actin structure modulation and phytohormone signal transduction.

Deciphering the evolution and complexity of wheat germplasm from a genomic perspective.

Bread wheat provides an essential fraction of the daily calorific intake for humanity. Due to its huge and complex genome, progress in studying on the wheat genome is substantially trailed behind those of the other two major crops, rice and maize, for at least a decade. With rapid advances in genome assembling and reduced cost of high-throughput sequencing, emerging de novo genome assemblies of wheat and whole-genome sequencing data are leading to a paradigm shift in wheat research. Here, we review recent progress in dissecting the complex genome and germplasm evolution of wheat since the release of the first high-quality wheat genome. New insights have been gained in the evolution of wheat germplasm during domestication and modern breeding progress, genomic variations at multiple scales contributing to the diversity of wheat germplasm, and complex transcriptional and epigenetic regulations of functional genes in polyploid wheat. Genomics databases and bioinformatics tools meeting the urgent needs of wheat genomics research are also summarized. The ever-increasing omics data, along with advanced tools and well-structured databases, are expected to accelerate deciphering the germplasm and gene resources in wheat for future breeding advances.

The longitudinal change pattern of cognitive subtypes in medication-free patients with major depressive disorder: a cluster analysis.

This study aimed to investigate whether there are different cognitive subtypes in patients with major depressive disorder (MDD) and the change pattern of cognitive clusters across the course of MDD. A battery of comprehensive cognitive tests was used to assess the executive function, processing speed, attention, and memory of 153 medication-free patients and 142 healthy controls (HCs). After 6 months of treatment with antidepressants, 87 patients completed cognitive tests again. K-means cluster analysis was performed to determine the cognitive subtypes. A preserved cognition cluster and an impaired cognition cluster were identified in the acute episode phase and the 6-month follow-up phase. 80.5% of the patients remained in their original subgroup after 6 months of treatment. The impaired cognition cluster during the 6-month follow-up period could be predicted by impaired cognition during the episode phase, disease state (remission or non-remission), current illness duration, and education level. This study supporting the heterogeneity of cognitive performance across the course of disease in patients with MDD using cluster analysis. It was found that cognitive impairment during depressive episodes was predictive of poorer cognitive performance even after treatment with antidepressants. Therefore, interventions targeting cognitive function from the early stages of MDD is essential.

Thermosensitive SUMOylation of TaHsfA1 defines a dynamic ON/OFF molecular switch for the heat stress response in wheat.

Dissecting genetic components in crop plants associated with heat stress (HS) sensing and adaptation will facilitate the design of modern crop varieties with improved thermotolerance. However, the molecular mechanisms underlying the ON/OFF switch controlling HS responses (HSRs) in wheat (Triticum aestivum) remain largely unknown. In this study, we focused on the molecular action of TaHsfA1, a class A heat shock transcription factor, in sensing dynamically changing HS signals and regulating HSRs. We show that the TaHsfA1 protein is modified by small ubiquitin-related modifier (SUMO) and that this modification is essential for the full transcriptional activation activity of TaHsfA1 in triggering downstream gene expression. During sustained heat exposure, the SUMOylation of TaHsfA1 is suppressed, which partially reduces TaHsfA1 protein activity, thereby reducing the intensity of downstream HSRs. In addition, we demonstrate that TaHsfA1 interacts with the histone acetyltransferase TaHAG1 in a thermosensitive manner. Together, our findings emphasize the importance of TaHsfA1 in thermotolerance in wheat. In addition, they define a highly dynamic SUMOylation-dependent "ON/OFF" molecular switch that senses temperature signals and contributes to thermotolerance in crops.

The bridge symptoms of childhood trauma, sleep disorder and depressive symptoms: a network analysis.

BACKGROUND: This study aimed to elucidate the characteristics of symptom network of childhood trauma (CT) and sleep disorder (SD) in Chinese adolescents, with the influence of depressive symptoms taken into account. METHOD: A total of 1301 adolescent students were included, and their CT, SD and depressive symptoms were measured using the Pittsburgh sleep quality index (PSQI), the Childhood Trauma Questionnaire-Short Form (CTQ-SF), and The Patient Health Questionnaire-9 (PHQ-9), respectively. Central symptoms and bridge symptoms were identified based on centrality indices and bridge centrality indices, respectively. Network stability was examined using the case-dropping procedure. RESULTS: In CT and SD symptom network, emotional abuse and sleep quality symptoms had the highest centrality values, and two bridge symptoms, i.e., emotional abuse and sleep disturbance symptoms, were also identified. In symptom network for CT, SD, and depressive symptoms, sleeping difficulty symptoms, daily dysfunction symptoms, and emotional abuse appeared to be potential bridge symptoms. In symptom network of CT, SD, and depressive symptoms (excluding the symptom of sleeping difficulty), daily dysfunction symptoms, emotional abuse, and sleep disturbance symptoms appeared to be bridge symptoms. CONCLUSIONS: In this study, emotional abuse and poor sleep quality were found to be central symptoms in the CT-SD network structure among Chinese adolescent students, with daytime dysfunction as the bridge symptom in the CT-SD-depression network structure. Systemic multi-level interventions targeting the central symptoms and bridge symptoms may be effective in alleviating the co-occurrence of CT, SD and depression in this population.

Pangenome-based trajectories of intracellular gene transfers in Poaceae unveil high cumulation in Triticeae.

Intracellular gene transfers (IGTs) between the nucleus and organelles, including plastids and mitochondria, constantly reshape the nuclear genome during evolution. Despite the substantial contribution of IGTs to genome variation, the dynamic trajectories of IGTs at the pangenomic level remain elusive. Here, we developed an approach, IGTminer, that maps the evolutionary trajectories of IGTs using collinearity and gene reannotation across multiple genome assemblies. We applied IGTminer to create a nuclear organellar gene (NOG) map across 67 genomes covering 15 Poaceae species, including important crops. The resulting NOGs were verified by experiments and sequencing data sets. Our analysis revealed that most NOGs were recently transferred and lineage specific and that Triticeae species tended to have more NOGs than other Poaceae species. Wheat (Triticum aestivum) had a higher retention rate of NOGs than maize (Zea mays) and rice (Oryza sativa), and the retained NOGs were likely involved in photosynthesis and translation pathways. Large numbers of NOG clusters were aggregated in hexaploid wheat during 2 rounds of polyploidization, contributing to the genetic diversity among modern wheat accessions. We implemented an interactive web server to facilitate the exploration of NOGs in Poaceae. In summary, this study provides resources and insights into the roles of IGTs in shaping interspecies and intraspecies genome variation and driving plant genome evolution.