Project description:Common wheat is one of the most widely cultivated staple crops worldwide. Elucidating the gene regulatory network will provide essential information for mechanism studies and targeted manipulation of gene activity for breeding. However, detecting cis-regulatory elements and transcription factor (TF) bindings in the extremely large intergenic regions of the wheat genome is challenging. Linking cis-regulatory elements and TF binding to target genes is even more difficult given that enhancers can function irrespective of the strand and distance from target genes. Combining genome-wide TF binding profiles, epigenomic patterns, and transcriptome analysis is a compelling approach to detect the hierarchical regulatory network. We generated and collected 189 TF binding profiles, 90 epigenomic datasets, and 2,356 transcriptomic datasets in common wheat, which were further integrated using machine learning approach to infer direct target genes and the hierarchical regulatory network. We developed a web-based platform, Wheat-RegNet, that provides four major functions: (i) to identify regulatory elements regulating input gene(s), and to infer the tissue and environmental response specificity; (ii) to identify the TFs responsible for regulating input gene(s) or locus/loci; (iii) to construct the hierarchical regulatory network regulating input gene(s); and (iv) to browse hundreds of TF binding, epigenomic, and transcriptomic profiles of an input region or gene(s). Well-organized results and multiple tools for interactive visualization are available through a user-friendly web interface, making Wheat-RegNet a highly useful resource for exploring gene regulatory information for hypothesis-driven studies and for targeted manipulation for breeding research in common wheat. Wheat-RegNet is freely available at http://bioinfo.sibs.ac.cn/Wheat-RegNet
Project description:Wheat panicle development is a coordinated process of proliferation and differentiation with distinctive phase and architecture changes. However, the multiple genes involved networks controlling this process remain enigmatic. Here, we characterized and dissected common wheat panicles in the stages of vegetative stage before elongation, elongation, single ridge, double ridge, glume primodium differentiation and floret differentiation, respectively, followed by RNA-seq and bioinformatics analysis to study genome-wide mRNA transcriptome profiling in wheat early spike development. High gene expression correlations between any two stages (R2>0.97) and only 4000 Differentially Expressed Genes (DEGs) out of 49624 expressed transcripts in all stages indicated that wheat early panicle development is just controlled by an small proportion of important genes. Three subgenomes (A, B and D) contribute equally to this process. K-means clustering analysis revealed the dynamic expression patterns of DEGs and Hierarchical Clustering analysis demonstrated that single bridge stage and double bridge stage are most important for wheat panicle development. Interestingly, 306 transcription factors (TFs) with various functions from different families were identified and the spatial-temporal expression patterns of some were verified by quantitative PCR or in situ hybridization. At early stages, repressing flowering TFs combined with AP2/ERF TFs and cytokinin promote inflorescence meristem development and repress meristem differentiation. At single ridge and double ridge stages, highly expressed stress-response TFs balance the interaction between stress response and development. During reproductive stages, crosstalk between auxin and cytokinin coordinate the meristem proliferation and differentiation, and promoting flowering TFs with polarity establishment TFs and MADS-box TFs promote floral meristem generation and floral organ identity and development. This dataset provided an ideal resource for wheat panicle developmental research. Our study uncovered the regulatory network for coordinated wheat early spike development and would eventually contribute to the improvement of grain number and crop yield.
Project description:Wheat dwarf virus (WDV) is a major constraint to global wheat production, causing severe yield losses and economic disruption. Understanding the molecular basis of wheat–WDV interactions is essential for developing resistant cultivars. Non-coding RNAs (ncRNAs), including long non-coding RNAs (lncRNAs) and microRNAs (miRNAs), are key regulators of gene expression and defence. This study identified ncRNAs involved in wheat responses to WDV, including host lncRNAs, miRNAs, and viral small interfering RNAs (siRNAs) targeting WDV genomic regions. High-throughput sequencing revealed extensive ncRNA reprogramming under WDV infection. A total of 437 differentially expressed lncRNAs (DElncRNAs) and 58 miRNAs (DEmiRNAs) were detected. Resistant genotypes displayed more DElncRNAs (204 in Svitava; 163 in Fengyou 3) than the susceptible Akteur (141). In Akteur, 66.7% of DElncRNAs were downregulated, whereas in Svitava, 56.9% were upregulated. Akteur also exhibited more DEmiRNAs (28) than resistant genotypes (15), with predominant downregulation. A co-expression network analysis revealed 391 significant DElncRNA–mRNA interactions mediated by 16 miRNAs. The lncRNA XLOC_058282 was linked to 298 transcripts in resistant genotypes, suggesting a central role in the host defence. Functional annotation showed enrichment in signalling, metabolic, and defence-related pathways. Small RNA profiling identified 1166 differentially expressed sRNAs targeting WDV, including conserved hotspots and 408 genotype-specific sites in Akteur versus Fengyou 3. Infected plants displayed longer sRNAs, a sense-strand bias, and a 5′ uridine preference, but lacked typical 21–24 nt phasing. These findings highlight the central roles of ncRNAs in orchestrating wheat antiviral defence and provide a molecular framework for breeding virus-resistant wheat.
Project description:Barley contains a much higher content of bioactive substances than wheat. In order to investigate the effect of genome interaction between barley and wheat on phytosterol content, we used a series of barley chromosome addition lines of common wheat. The wheat 38k-microarray was utilized for screening of genes with expression levels specifically increased by an additive effect or synergistic action between wheat and barley chromosomes. We determined the overall expression pattern of genes related to phytosterol biosynthesis in wheat and in each addition line. Together with determining the phytosterol levels of wheat, barley and each addition line, we assess the critical genes in the phytosterol pathway that can be expressed to promote phytosterol levels.
Project description:Histone lysine crotonylation (Kcr) is a newly discovered protein post-translational modification (PTM), which was detected from yeast to humans and is mainly related with active transcription. With the development of proteomics technologies, high abundance of non-histone proteins modified by Kcr was also found recently. Here, we first report that lysine Kcr also occurs on cytoplasmic and mitochondrial proteins in common wheat (Triticum aestivum L.). We identified 4,696 Lys-acetylated sites on 1,726 proteins which involved in a wide variety of biological processes, such as chromatin-associated processes, Calvin-Benson cycle, glycolysis, protein metabolism and transport, which representing the largest dataset of lysine acylation proteome reported in the plant kingdom. Interestingly, 98 proteins were involved in multiple processes of photosynthesis, suggesting an important role of lysine Kcr in processes. In addition, 21 potentially specific Kcr motifs in wheat were detected. The protein interaction network analysis revealed that diverse interactions are modulated by protein Kcr. The overlap between Kcr and acetylation (Kac) indicated that they may coordinately regulate the function of some proteins in common wheat. Futhermore, comparative analysis indicated that lysine Kcr is conserved between common wheat and Nicotiana tabacum. Taken together, this study provided the first global survey of Kcr in wheat, making a promising starting point for further functional analysis of Kcr in plants.
Project description:Barley contains a much higher content of bioactive substances than wheat. In order to investigate the effect of genome interaction between barley and wheat on phytosterol content, we used a series of barley chromosome addition lines of common wheat. The wheat 38k-microarray was utilized for screening of genes with expression levels specifically increased by an additive effect or synergistic action between wheat and barley chromosomes. We determined the overall expression pattern of genes related to phytosterol biosynthesis in wheat and in each addition line. Together with determining the phytosterol levels of wheat, barley and each addition line, we assess the critical genes in the phytosterol pathway that can be expressed to promote phytosterol levels. Gene expression levels of each barley chromosome addition line of common wheat were compared to that of common wheat. Total RNA samples were isolated from the 2-week-old seedling leaves. The experiments were replicated three times for each addition line using independent samples.
Project description:Physiologically, albumin is produced by hepatocytes. It remains largely unknown how patients are capable of maintaining essential albumin levels even in the condition of liver failure. Here, we delineate a hierarchical regulatory network that controls albumin transcription under different pathophysiological conditions. The ALB core promoter possesses a TATA box and nucleosome-free area, which allows constitutive binding of RNA Pol II and thus initiation of transcription. In normal conditions, HNF4α and C/EBPα facilitate albumin transcription through binding to its promoter. In severely damaged livers, hepatocellular HNF4α and C/EBPα expression is often inhibited. The absence of HNF4 and C/EBPα increases hedgehog ligand biosynthesis. Hedgehog upregulates FOXA2 expression through transcription factor GLI2 binding to the FOXA2 promoter. Subsequently, FOXA2 maintains albumin expression in the hepatocytes lacking HNF4α and C/EBPα. In patients with massive hepatocyte loss, the expression of albumin is activated in liver progenitor cells. Albumin transcription in these cells is regulated by HNF4α or FOXA2. Taken together, HNF4α, C/EBPα and FOXA2 form a hierarchical regulatory network that ensures stable albumin expression even in pathophysiological conditions.