Transcriptional reference map of hormone responses in wheat spikes.

BACKGROUND: Phytohormones are key regulators of plant growth, development, and signalling networks involved in responses to diverse biotic and abiotic stresses. Transcriptional reference maps of hormone responses have been reported for several model plant species such as Arabidopsis thaliana, Oryza sativa, and Brachypodium distachyon. However, because of species differences and the complexity of the wheat genome, these transcriptome data are not appropriate reference material for wheat studies. RESULTS: We comprehensively analysed the transcriptomic responses in wheat spikes to seven phytohormones, including indole acetic acid (IAA), gibberellic acid (GA), abscisic acid (ABA), ethylene (ET), cytokinin (CK), salicylic acid (SA), and methyl jasmonic acid (MeJA). A total of 3386 genes were differentially expressed at 24 h after the hormone treatments. Furthermore, 22.7% of these genes exhibited overlapping transcriptional responses for at least two hormones, implying there is crosstalk among phytohormones. We subsequently identified genes with expression levels that were significantly and differentially induced by a specific phytohormone (i.e., hormone-specific responses). The data for these hormone-responsive genes were then compared with the transcriptome data for wheat spikes exposed to biotic (Fusarium head blight) and abiotic (water deficit) stresses. CONCLUSION: Our data were used to develop a transcriptional reference map of hormone responses in wheat spikes.

Re-acquisition of the brittle rachis trait via a transposon insertion in domestication gene Q during wheat de-domestication.

De-domestication is a unique evolutionary process during which crops re-acquire wild-like traits to survive and persist in agricultural fields without the need for human cultivation. The re-acquisition of seed dispersal mechanisms is crucial for crop de-domestication. Common wheat is an important cereal crop worldwide. Tibetan semi-wild wheat is a potential de-domesticated common wheat subspecies. However, the crucial genes responsible for its brittle rachis trait have not been identified. Genetic mapping, functional analyses and phylogenetic analyses were completed to identify the gene associated with Qbr.sau-5A, which is a major locus for the brittle rachis trait of Tibetan semi-wild wheat. The cloned Qbr.sau-5A gene is a new Q allele (Qt ) with a 161-bp transposon insertion in exon 5. Although Qt is expressed normally, its encoded peptide lacks some key features of the APETALA2 family. The abnormal functions of Qt in developing wheat spikes result in brittle rachises. Phylogenetic and genotyping analyses confirmed that Qt originated from Q in common wheat and is naturally distributed only in Tibetan semi-wild wheat populations. The identification of Qt provides new evidence regarding the origin of Tibetan semi-wild wheat, and new insights into the re-acquisition of wild traits during crop de-domestication.

Fusarium graminearum ATP-Binding Cassette Transporter Gene FgABCC9 Is Required for Its Transportation of Salicylic Acid, Fungicide Resistance, Mycelial Growth and Pathogenicity towards Wheat.

ATP-binding cassette (ABC) transporters hydrolyze ATP to transport a wide range of substrates. Fusarium graminearum is a major causal agent of Fusarium head blight, which is a severe disease in wheat worldwide. FgABCC9 (FG05_07325) encodes an ABC-C (ABC transporter family C) transporter in F. graminearum, which was highly expressed during the infection in wheat and was up-regulated by the plant defense hormone salicylic acid (SA) and the fungicide tebuconazole. The predicted tertiary structure of the FgABCC9 protein was consistent with the schematic of the ABC exporter. Deletion of FgABCC9 resulted in decreased mycelial growth, increased sensitivity to SA and tebuconazole, reduced accumulation of deoxynivalenol (DON), and less pathogenicity towards wheat. Re-introduction of a functional FgABCC9 gene into ΔFgABCC9 recovered the phenotypes of the wild type strain. Transgenic expression of FgABCC9 in Arabidopsis thaliana increased the accumulation of SA in its leaves without activating SA signaling, which suggests that FgABCC9 functions as an SA exporter. Taken together, FgABCC9 encodes an ABC exporter, which is critical for fungal exportation of SA, response to tebuconazole, mycelial growth, and pathogenicity towards wheat.

Identification of Hub genes with prognostic values in colorectal cancer by integrated bioinformatics analysis.

BACKGROUND: Our study aimed to investigate the Hub genes and their prognostic value in colorectal cancer (CRC) via bioinformatics analysis. METHODS: The data set of colorectal cancer was downloaded from the GEO database (GSE21510, GSE110224 and GSE74602) for differential expression analysis using the GEO2R tool. Hub genes were screened by protein-protein interaction (PPI) comprehensive analysis. GEPIA was used to verify the expression of Hub genes and evaluate its prognostic value. The protein expression of Hub gene in CRC was analyzed using the Human Protein Atlas database. The cBioPortal was used to analyze the type and frequency of Hub gene mutations, and the effects of mutation on the patients' prognosis. The TIMER database was used to study the correlation between Hub genes and immune infiltration in CRC. Gene set enrichment analysis (GSEA) was used to explore the biological function and signal pathway of the Hub genes and corresponding co-expressed genes. RESULTS: We identified 346 differentially expressed genes (DEGs), including 117 upregulated and 229 downregulated. Four Hub genes (AURKA, CCNB1, EXO1 and CCNA2) were selected by survival analysis and differential expression validation. The protein and mRNA expression levels of AURKA, CCNB1, EXO1 and CCNA2 were higher in CRC tissues than in adjacent tissues. There were varying degrees of immune cell infiltration and gene mutation of Hub genes, especially B cells and CD8+ T cells. The results of GSEA showed that Hub genes and their co-expressed genes mainly participated in chromosome segregation, DNA replication, translational elongation and cell cycle. CONCLUSION: Overexpression of AURKA, CCNB1, CCNA2 and EXO1 had a better prognosis for CRC and this effect was correlation with gene mutation and infiltration of immune cells.

Essential oil from Ligusticum chuanxiong Hort. Alleviates lipopolysaccharide-induced neuroinflammation: Integrating network pharmacology and molecular mechanism evaluation.

ETHNOPHARMACOLOGICAL RELEVANCE: Chuanxiong, the rhizome of Ligusticum chuanxiong Hort., is an ancient herbal medicine that has gained extensive popularity in alleviating migraines with satisfying therapeutic effects in China. As the major bioactive component of Chuanxiong, the essential oil also exerts a marked impact on the treatment of migraine. It is widely recognized that neuroinflammation contributes to migraine. However, it remains unknown whether Chuanxiong essential oil has anti-neuroinflammatory activity. AIM OF THE STUDY: To explore the anti-neuroinflammatory properties of Chuanxiong essential oil and its molecular mechanisms by network pharmacology analysis and in vitro experiments. MATERIALS AND METHODS: Gas chromatography-mass spectrometry (GC-MS) was used to identify the chemical components of Chuanxiong essential oil. Public databases were used to predict possible targets, build the protein-protein interaction network (PPI), and perform Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. Moreover, cytological experiments, nitric oxide assay, enzyme-link immunosorbent assay, western blotting, and immunofluorescence assay were adopted to prove the critical signaling pathway in lipopolysaccharide (LPS)-induced BV2 cells. RESULTS: Thirty-six compounds were identified from Chuanxiong essential oil by GC-MS, and their corresponding putative targets were predicted. The network pharmacology study identified 232 candidate targets of Chuanxiong essential oil in anti-neuroinflammation. Furthermore, Chuanxiong essential oil was found to potentially affect the C-type lectin receptor, FoxO, and NF-κB signaling pathways according to the KEGG analysis. Experimentally, we verified that Chuanxiong essential oil could significantly reduce the overproduction of inflammatory mediators and pro-inflammatory factors via the NF-κB signaling pathway. CONCLUSION: Chuanxiong essential oil alleviates neuroinflammation through the NF-κB signaling pathway, which provides a theoretical foundation for a better understanding of the clinical application of Chuanxiong essential oil in migraine treatment.

Functional Analysis of FgNahG Clarifies the Contribution of Salicylic Acid to Wheat (Triticum aestivum) Resistance against Fusarium Head Blight.

Salicylic acid (SA) is a key defense hormone associated with wheat resistance against Fusarium head blight, which is a severe disease mainly caused by Fusarium graminearum. Although F. graminearum can metabolize SA, it remains unclear how this metabolic activity affects the wheat⁻F. graminearum interaction. In this study, we identified a salicylate hydroxylase gene (FG05_08116; FgNahG) in F. graminearum. This gene encodes a protein that catalyzes the conversion of SA to catechol. Additionally, FgNahG was widely distributed within hyphae. Disrupting the FgNahG gene (ΔFgNahG) led to enhanced sensitivity to SA, increased accumulation of SA in wheat spikes during the early infection stage and inhibited development of head blight symptoms. However, FgNahG did not affect mycotoxin production. Re-introducing a functional FgNahG gene into the ΔFgNahG mutant recovered the wild-type phenotype. Moreover, the expression of FgNahG in transgenic Arabidopsis thaliana decreased the SA concentration and the resistance of leaves to F. graminearum. These results indicate that the endogenous SA in wheat influences the resistance against F. graminearum. Furthermore, the capacity to metabolize SA is an important factor affecting the ability of F. graminearum to infect wheat plants.

Fusarium graminearum FgCWM1 Encodes a Cell Wall Mannoprotein Conferring Sensitivity to Salicylic Acid and Virulence to Wheat.

Fusarium graminearum causes Fusarium head blight (FHB), a devastating disease of wheat. Salicylic acid (SA) is involved in the resistance of wheat to F. graminearum. Cell wall mannoprotein (CWM) is known to trigger defense responses in plants, but its role in the pathogenicity of F. graminearum remains unclear. Here, we characterized FgCWM1 (FG05_11315), encoding a CWM in F. graminearum. FgCWM1 was highly expressed in wheat spikes by 24 h after initial inoculation and was upregulated by SA. Disruption of FgCWM1 (ΔFgCWM1) reduced mannose and protein accumulation in the fungal cell wall, especially under SA treatment, and resulted in defective fungal cell walls, leading to increased fungal sensitivity to SA. The positive role of FgCWM1 in mannose and protein accumulation was confirmed by its expression in Saccharomyces cerevisiae. Compared with wild type (WT), ΔFgCWM1 exhibited reduced pathogenicity toward wheat, but it produced the same amount of deoxynivalenol both in culture and in spikes. Complementation of ΔFgCWM1 with FgCWM1 restored the WT phenotype. Localization analyses revealed that FgCWM1 was distributed on the cell wall, consistent with its structural role. Thus, FgCWM1 encodes a CWM protein that plays an important role in the cell wall integrity and pathogenicity of F. graminearum.

An Overexpressed Q Allele Leads to Increased Spike Density and Improved Processing Quality in Common Wheat (Triticum aestivum).

Spike density and processing quality are important traits in modern wheat production and are controlled by multiple gene loci. The associated genes have been intensively studied and new discoveries have been constantly reported during the past few decades. However, no gene playing a significant role in the development of these two traits has been identified. In the current study, a common wheat mutant with extremely compact spikes and good processing quality was isolated and characterized. A new allele (Qc1 ) of the Q gene (an important domestication gene) responsible for the mutant phenotype was cloned, and the molecular mechanism for the mutant phenotype was studied. Results revealed that Qc1 originated from a point mutation that interferes with the miRNA172-directed cleavage of Q transcripts, leading to its overexpression. It also reduces the longitudinal cell size of rachises, resulting in an increased spike density. Furthermore, Qc1 increases the number of vascular bundles, which suggests a higher efficiency in the transportation of assimilates in the spikes of the mutant than that of wild type. This accounts for the improved processing quality. The effects of Qc1 on spike density and wheat processing quality were confirmed by analyzing nine common wheat mutants possessing four different Qc alleles. These results deepen our understanding of the key roles of Q gene, and provide new insights for the potential application of Qc alleles in wheat quality breeding.

Linoleic acid isomerase gene FgLAI12 affects sensitivity to salicylic acid, mycelial growth and virulence of Fusarium graminearum.

Fusarium graminearum is the major causal agent of fusarium head blight in wheat, a serious disease worldwide. Linoleic acid isomerase (LAI) catalyses the transformation of linoleic acid (LA) to conjugated linoleic acid (CLA), which is beneficial for human health. We characterised a cis-12 LAI gene of F. graminearum (FGSG_02668; FgLAI12), which was downregulated by salicylic acid (SA), a plant defence hormone. Disruption of FgLAI12 in F. graminearum resulted in decreased accumulation of cis-9,trans-11 CLA, enhanced sensitivity to SA, and increased accumulation of LA and SA in wheat spikes during infection. In addition, mycelial growth, accumulation of deoxynivalenol, and pathogenicity in wheat spikes were reduced. Re-introduction of a functional FgLAI12 gene into ΔFgLAI12 recovered the wild-type phenotype. Fluorescent microscopic analysis showed that FgLAI12 protein was usually expressed in the septa zone of conidia and the vacuole of hyphae, but was expressed in the cell membrane of hyphae in response to exogenous LA, which may be an element of LA metabolism during infection by F. graminearum. The cis-12 LAI enzyme encoded by FgLAI12 is critical for fungal response to SA, mycelial growth and virulence in wheat. The gene FgLAI12 is potentially valuable for biotechnological synthesis of cis-9,trans-11 CLA.

The γ-gliadin-like γ-prolamin genes in the tribe Triticeae.

The γ-prolamins are important components of seed storage proteins in wheat and other Triticeae species. Here, the γ-prolamin genes from the diploid Triticeae species were systemically characterized. Most of the γ-prolamins (except 75 K γ-secalins) characterized were defined as γ-gliadin-like γ-prolamins, since they shared same characteristic model structure with γ-gliadins. Over one-third of these putatively functional γ-prolamin peptides contained different number of cysteine residues as compared to the eight residues present in γ-gliadins. Sequence polymorphism and linkage disequilibrium analyses showed the conservation of γ-prolamin genes in Triticeae species under evolutionary selection. Phylogenetic analyses indicated that these γ-prolamin genes can not be clearly separated according to their genomic origins, reflecting the conservation of γ-gliadinlike γ-prolamin genes after the divergence of Triticeae species. A screening of coeliac disease (CD) toxic epitopes shows that the γ-prolamins from some other genomes contain much fewer epitopes than those from the A, S (B) and D genomes of wheat. These findings contribute to better understanding of γ-prolamin family in Triticeae and build a ground for breeding less CD-toxic wheat cultivars.