Search Results (101)

Rhizoctonia solani is a necrotrophic phytopathogenic fungus that causes disease in various crops. In agriculture, many crops suffer from root or seedling rot caused by this soil-borne pathogen, whereas cabbage and rice develop lesion-like symptoms on aboveground tissues. Diseases caused by R. solani are generally controlled using chemical fungicides; however, environmentally friendly alternatives are needed for sustainable agriculture. In this study, we evaluated the efficacy of lecithin, a mixture of phospholipids previously registered in Japan as an agrochemical for controlling cucumber powdery mildew, against Rhizoctonia diseases. In cabbage, foliar spraying of 0.2–1.0% soybean lecithin effectively suppressed leaf symptoms caused by R. solani isolate RhiCa-2, which was identified as AG-1 IB. In rice and Brachypodium distachyon, 0.2–1.0% lecithin significantly suppressed leaf symptoms induced by R. solani AG-1 IA. Hyphal staining of inoculated leaves revealed reduced hyphal density on lecithin-treated leaves. Consistently, hyphal growth of R. solani on cellophane placed on water agar was retarded by lecithin treatment. However, 5.0% lecithin induced phytotoxicity in B. distachyon. Egg yolk-derived lecithin also exhibited disease-suppressive activity in cabbage and B. distachyon, with efficacy comparable to that of soybean lecithin under the conditions tested. These results suggest that lecithin suppresses foliar infection by R. solani, at least in part, through direct inhibitory effects on fungal hyphae, and may serve as a potential alternative material for disease control in sustainable crop production. Full article

Silicon (Si) accumulation is a widespread anti-herbivore defence in grasses, yet little is known about how insects counteract silicification, including via compensatory feeding, or whether Si-mediated changes in plant stoichiometry also influence herbivore performance. We examined how Si supplementation alters foliar Si, carbon (C), nitrogen (N), and phosphorus (P) in two grasses with contrasting accumulation strategies, Brachypodium distachyon (high accumulator) and Lolium arundinaceum (moderate accumulator), and the consequences for growth and feeding by Helicoverpa armigera. Plants were grown hydroponically with or without Si, and herbivore relative growth rate (RGR), relative consumption (RC), and Efficiency of Conversion of Ingested food (ECI) were measured. Si supplementation had stronger effects on herbivore performance in B. distachyon compared with L. arundinaceum. RGR declined by 126% on B. distachyon compared with 40% on L. arundinaceum. Herbivores increased RC on Si-supplemented L. arundinaceum, with RC positively correlated with foliar Si concentrations, but no compensatory feeding occurred on B. distachyon. N and P concentrations were positively correlated with RGR in L. arundinaceum and ECI in B. distachyon. In conclusion, the degree of Si accumulation in grasses influences both plant stoichiometry and has contrasting impacts on herbivore feeding strategies. Full article

Brachypodium distachyon has become a widely studied model plant due to its small genome, ease of cultivation under controlled conditions, and value for synteny and molecular studies. Regarding disease, Fusarium is one of the main fungal genera infecting cereal crops, F. cerealis, F. graminearum, F. poae, and F. pseudograminearum being isolated frequently from several agricultural regions. Therefore, the present study aimed to evaluate three pathosystems, combining three hosts (B. distachyon, barley, and wheat) with four Fusarium species to confirm the use of B. distachyon in Fusarium–crop system models. Three controlled experiments were performed to assess the impact on seeds, roots, and spikes. Variables such as germination inhibition, McKinney’s index, percentage of necrosis, area under the disease progress curve, disease incidence, disease severity, and grain weight were measured. Regarding Fusarium species, the results confirm that F. pseudograminearum could be more aggressive on roots, while F. graminearum affects spikes more severely. In contrast, F. cerealis and F. poae are generally moderate to weak pathogens with irregular behaviour depending on the plant species or genotype. No clear varietal resistance pattern emerged except for wheat genotypes with a known resistance/susceptibility QTL. The present study highlights the importance of using multiple experiments for accurate phenotype characterisation, as relying on a single technique is insufficient. In conclusion, the results presented in the manuscript provide valuable insights into Fusarium spp.–B. distachyon interactions and resistance selection based on seed, root, and spike assessments. Moreover, this work confirmed the use of Brachypodium as a model plant for Fusarium–plant interaction studies. Full article

Xyloglucan endotransglucosylase/hydrolases (XTHs) are a class of cell wall-associated enzymes involved in the construction and remodeling of cellulose/xyloglucan crosslinks. However, knowledge of this gene family in the model monocot Brachypodium distachyon is limited. A total of 29 BdXTH genes were identified from the whole genome, and these were further divided into three subgroups (Group I/II, Group III, and the Ancestral Group) through evolutionary analysis. Gene structure and protein motif analyses indicate that closely clustered BdXTH genes are relatively conserved within each group. A highly conserved amino acid domain (DEIDFEFLG) responsible for catalytic activity was identified in all BdXTH proteins. We detected three pairs of segmentally duplicated BdXTH genes and five groups of tandemly duplicated BdXTH genes, which played vital roles in the expansion of the BdXTH gene family. Cis-elements related to hormones, growth, and abiotic stress responses were identified in the promoters of each BdXTH gene, and when roots were treated with two abiotic stresses (salinity and drought) and four plant hormones (IAA, auxin; GA3, gibberellin; ABA, abscisic acid; and BR, brassinolide), the expression levels of many BdXTH genes changed significantly. Transcriptional analyses of the BdXTH genes in 38 tissue samples from the publicly available RNA-seq data indicated that most BdXTH genes have distinct expression patterns in different tissues and at different growth stages. Overexpressing the BdXTH27 gene in Brachypodium led to reduced root length in transgenic plants, which exhibited higher cellulose levels but lower hemicellulose levels compared to wild-type plants. Our results provide valuable information for further elucidation of the biological functions of BdXTH genes in the model grass B. distachyon. Full article

Abscisic acid (ABA)-stress-ripening, or ABA-, stress-, and ripening-induced (ASR) proteins play an important role in responses to environmental stimuli. A total of ten barley HvASRs were identified in this study, which were unevenly distributed on three chromosomes. ASRs from barley, wheat, Brachypodium distachyon, rice, maize, foxtail millet, and tomato were classified into two distinct clusters based on phylogenetic analysis. Notably, ASRs from Poaceae were evenly distributed between these two clusters. HvASRs contained a typical ABA/WDS domain, and exhibited similar motif arrangements. Two gene pairs of tandem duplicates (HvASR4/5/6/7 and HvASR8/9) were identified among HvASRs. Cis-acting elements involved in hormone and stress responses, including ABRE, MYB, ARE, and STRE, were consistently identified in the promoters of HvASRs. The expression of HvASRs was substantially influenced by salt, osmotic, and ABA treatments in the roots and leaves of barley seedlings. HvASR2 acts as a transcriptional repressor, whereas HvASR3 serves as a transcriptional activator. These results enhance our understanding of the HvASR family and provide a foundation for further functional characterization. Full article

Rhizoctonia solani is a basidiomycete phytopathogenic fungus that causes rapid necrosis in a wide range of crop species, leading to substantial agricultural losses worldwide. The species complex is divided into 13 anastomosis groups (AGs) based on hyphal fusion compatibility and further subdivided by culture morphology. While R. solani classifications were shown to be independent of host specificity, it remains unclear whether different R. solani isolates share similar virulence mechanisms. Here, we investigated the infectivity of Japanese R. solani isolates on Brachypodium distachyon and barley. Two isolates, AG-1 IA (from rice) and AG-4 HG-I+II (from cauliflower), infected leaves of both plants, but only AG-4 HG-I+II infected roots. B. distachyon accessions Bd3-1 and Gaz-4 and barley cultivar ‘Morex’ exhibited enhanced resistance to both isolates compared to B. distachyon Bd21 and barley cultivars ‘Haruna Nijo’ and ‘Golden Promise’. During AG-1 IA infection, but not AG-4 HG-I+II infection, resistant Bd3-1 and Morex induced genes for salicylic acid (SA) and N-hydroxypipecolic acid (NHP) biosynthesis. Pretreatment with SA or NHP conferred resistance to AG-1 IA, but not AG-4 HG-I+II, in susceptible B. distachyon Bd21 and barley Haruna Nijo. On the leaves of susceptible Bd21 and Haruna Nijo, AG-1 IA developed extensive mycelial networks with numerous infection cushions, which are specialized infection structures well-characterized in rice sheath blight. In contrast, AG-4 HG-I+II formed dispersed mycelial masses associated with underlying necrosis. We propose that the R. solani species complex encompasses at least two distinct infection strategies: AG-1 IA exhibits a hemibiotrophic lifestyle, while AG-4 HG-I+II follows a predominantly necrotrophic strategy. Full article

Cereal crops are affected by one of the most devastating diseases worldwide, known as Fusarium head blight (FHB), with Fusarium graminearum being the most isolated causal pathogen. Another species associated with this disease is Fusarium poae. This species has been considered a relatively weak pathogen compared to F. graminearum, but its importance has increased due to its occurrence in cereal grains worldwide. Considering the advantages of using B. distachyon as a plant model and the importance of F. poae in crops, our study aimed to evaluate the potential use of Brachypodium as a plant model to evaluate the compatible interaction with F. poae. Twelve Brachypodium spp. accessions from different countries were inoculated with a selected F. poae set of isolates. Disease severity, conidial quantification, fungal DNA biomass, and nivalenol quantification were assessed. The results showed a compatible interaction between Brachypodium accessions and Fusarium poae, which allowed the use of the model plant for future plant–pathogen interaction studies. Full article

The basic helix-loop-helix (bHLH) transcription factor (TF) family, the second-largest among eukaryotes, is known for its evolutionary and functional diversity across plant species. However, bHLH genes have not yet been characterized in Areca catechu. In this study, we identified 76 AcbHLH genes, which exhibit a variety of physicochemical properties. Phylogenetic analysis revealed evolutionary relationships between Arabidopsis thaliana bHLH genes (AtbHLH) and their counterparts in A. catechu (AcbHLH). These analyses also highlighted conserved amino acid motifs (S, R, K, P, L, A, G, and D), conserved domains, and evolutionary changes, such as insertions, deletions, and exon gains or losses. Promoter analysis of AcbHLH genes revealed 76 cis-elements related to growth, phytohormones, light, and stress. Gene duplication analysis revealed four tandem duplications and twenty-three segmental duplications, while AcbHLH63 in the Areca genome exhibited significant synteny with bHLH genes from A. thaliana, Vitis vinifera, Solanum lycopersicum, Brachypodium distachyon, Oryza sativa, and Zea mays. Furthermore, relative expression analysis showed that under drought stress (DS), AcbHLH22, AcbHLH39, AcbHLH45, and AcbHLH58 showed distinct upregulation in leaves at specific time points, while all nine AcbHLH genes were upregulated in roots. Under salt stress (SS), AcbHLH22, AcbHLH39, AcbHLH45, and AcbHLH58 were upregulated in leaves, and AcbHLH22, AcbHLH34, and AcbHLH39 exhibited differential expression in roots at various time points. This study provides valuable insights into the bHLH superfamily in A. catechu, offering a solid foundation for further investigation into its role in responding to abiotic stresses. Full article

There is an increasing demand for low-maintenance public garden models, and environmental stress on plants due to climate change is growing. As a result, the demand for developing new plant varieties based on native species for use in gardens in response to climate change has increased significantly. Many plants in the Poaceae family are applied for various purposes, including food crops, fodder grasses, ornamental plants, and medicinal plants. Additionally, native plants provide economic and ecological benefits, making them advantageous for use in gardens. However, there are some difficulties in Poaceae breeding studies and the utilization of wild native plants for breeding. Model plants can be utilized in breeding studies of Poaceae plant species. In this study, to identify Korean native Poaceae species with the potential for use not only as garden materials but also as model plants for breeding research in response to climate change, candidate species were selected from the Korean Plant Names Index (KPNI). A total of three Korean native plants in the Poaceae family, including Brachypodium sylvaticum, Setaria viridis, and Zoysia japonica, were selected, and their properties and genome information were compared with the existing representative model plants, Arabidopsis thaliana and Brachypodium distachyon. The current research status of B. sylvaticum, S. viridis, and Z. japonica has been summarized, and the genome size and other characteristics of these model plants have been compared and discussed. As a result, both A. thaliana (2n = 2x = 10) and B. distachyon (2n = 2x = 10) are annual C₃ plants, but B. sylvaticum (2n = 2x = 18) is a perennial C₃ plant, and S. viridis (2n = 2x = 18) is an annual C₄ plant. Thus, B. sylvaticum and S. viridis can be utilized as model plants for perennial C₃ plants and annual C₄ plants, respectively. Z. japonica (2n = 4x = 40) is a perennial C₄ plant, but it can be unsuitable as a model plant because it is an allotetraploid. The application of these newly selected candidate plants in breeding research can build a foundation for breeding native Poaceae plants in Korea in the new climate regime. Full article

The Multidrug and Toxic Compound Extrusion (MATE) proteins serve as pivotal transporters responsible for the extrusion of metabolites, thereby playing a significant role in both plant development and the detoxification of toxins. The MATE gene family within the Brachypodium distachyon, which is an important model organism of the Poaceae family, remains largely unexplored. Here, a comprehensive identification and analysis of MATE genes that complement B. distachyon were conducted. The BdMATE genes were systematically categorized into five distinct groups, predicated on an assessment of their phylogenetic affinities and protein structure. Furthermore, our investigation revealed that dispersed duplication has significantly contributed to the expansion of the BdMATE genes, with tandem and segmental duplications showing important roles, suggesting that the MATE genes in Poaceae species have embarked on divergent evolutionary trajectories. Examination of ω values demonstrated that BdMATE genes underwent purifying selection throughout the evolutionary process. Furthermore, collinearity analysis has confirmed a high conservation of MATE genes between B. distachyon and rice. The cis-regulatory elements analysis within BdMATEs promoters, coupled with expression patterns, suggests that BdMATEs play important roles during plant development and in response to phytohormones. Collectively, the findings presented establish a foundational basis for the subsequent detailed characterization of the MATE gene family members in B. distachyon. Full article

The alternative oxidase (AOX), a common terminal oxidase in the electron transfer chain (ETC) of plants, plays a crucial role in stress resilience and plant growth and development. Oat (Avena sativa), an important crop with high nutritional value, has not been comprehensively studied regarding the AsAOX gene family. Therefore, this study explored the responses and potential functions of the AsAOX gene family to various abiotic stresses and their potential evolutionary pathways. Additionally, we conducted a genome-wide analysis to explore the evolutionary conservation and divergence of AOX gene families among three Avena species (Avena sativa, Avena insularis, Avena longiglumis) and four Poaceae species (Avena sativa, Oryza sativa, Triticum aestivum, and Brachypodium distachyon). We identified 12 AsAOX, 9 AiAOX, and 4 AlAOX gene family members. Phylogenetic, motif, domain, gene structure, and selective pressure analyses revealed that most AsAOXs, AiAOXs, and AlAOXs are evolutionarily conserved. We also identified 16 AsAOX segmental duplication pairs, suggesting that segmental duplication may have contributed to the expansion of the AsAOX gene family, potentially preserving these genes through subfunctionalization. Chromosome polyploidization, gene structural variations, and gene fragment recombination likely contributed to the evolution and expansion of the AsAOX gene family as well. Additionally, we hypothesize that AsAOX2 may have potential function in resisting wounding and heat stresses, while AsAOX4 could be specifically involved in mitigating wounding stress. AsAOX11 might contribute to resistance against chromium and waterlogging stresses. AsAOX8 may have potential fuction in mitigating ABA-mediated stress. AsAOX12 and AsAOX5 are most likely to have potential function in mitigating salt and drought stresses, respectively. This study elucidates the potential evolutionary pathways of the AsAOXs gene family, explores their responses and potential functions to various abiotic stresses, identifies potential candidate genes for future functional studies, and facilitates molecular breeding applications in A. sativa. Full article

The model organism Neurospora crassa has been cultivated in laboratories since the 1920s and its saprotrophic lifestyle has been established for decades. However, beyond their role as saprotrophs, fungi engage in intricate relationships with plants, showcasing diverse connections ranging from mutualistic to pathogenic. Although N. crassa has been extensively investigated under laboratory conditions, its ecological characteristics remain largely unknown. In contrast, Brachypodium distachyon, a sweet grass closely related to significant crops, demonstrates remarkable ecological flexibility and participates in a variety of fungal interactions, encompassing both mutualistic and harmful associations. Through a comprehensive microscopic analysis using electron, fluorescence, and confocal laser scanning microscopy, we discovered a novel endophytic interaction between N. crassa and B. distachyon roots, where fungal hyphae not only thrive in the apoplastic space and vascular bundle but also may colonize plant root cells. This new and so far hidden trait of one of the most important fungal model organisms greatly enhances our view of N. crassa, opening new perspectives concerning the fungus‘ ecological role. In addition, we present a new tool for studying plant–fungus interspecies communication, combining two well-established model systems, which improves our possibilities of experimental design on the molecular level. Full article

The Tubby-like proteins (TLPs) gene family is a group of transcription factors found in both animals and plants. In this study, we identified twelve B. distachyon TLPs, divided into six groups based on conserved domains and evolutionary relationships. We predicted cis-regulatory elements involved in light, hormone, and biotic and abiotic stresses. The expression patterns in response to light and hormones revealed that BdTLP3, 4, 7, and 14 are involved in light responses, and BdTLP1 is involved in ABA responses. Furthermore, BdTLP2, 7, 9, and 13 are expressed throughout vegetative and reproductive stages, whereas BdTLP1, 3, 5, and 14 are expressed at germinating grains and early vegetative development, and BdTLP4, 6, 8, and 10 are expressed at the early reproduction stage. The natural variation in the eleven most diverged B. distachyon lines revealed high conservation levels of BdTLP1-6 to high variation in BdTLP7-14 proteins. Based on diversifying selection, we identified amino acids in BdTLP1, 3, 8, and 13, potentially substantially affecting protein functions. This analysis provided valuable information for further functional studies to understand the regulation, pathways involved, and mechanism of BdTLPs. Full article

BdGF14a, a 14-3-3 gene from Brachypodium distachyon, induced by salt, H₂O₂, and abscisic acid (ABA), improved tolerance to drought and salt in tobacco, with a higher survival rate and longer roots under these stresses. Additionally, physiological index analyses showed that the heterologous expression of BdGF14a induced higher expression levels of antioxidant enzymes and their activities, leading to lighter DAB and NBT staining, denoting decreased H₂O₂ content. Additionally, the lower MDA content and ion leakage indicated enhanced cell membrane stability. Moreover, exogenous ABA resulted in shorter roots and a lower stomatal aperture in BdGF14a transgenic plants. BdGF14a interacted with NtABF2 and regulated the expression of stress-related genes. However, adding an ABA biosynthesis inhibitor suppressed most of these changes. Furthermore, similar salt and drought resistance phenotypes and physiological indicators were characterized in tobacco plants expressing BdbZIP62, an ABRE/ABF that interacts with BdGF14a. And Y1H and LUC assays showed that BdGF14a could enhance the transcription regulation activity of NtABF2 and BdbZIP62, targeting NtNECD1 by binding to the ABRE cis-element. Thus, BdGF14a confers resistance to drought and salinity through interaction with BdbZIP62 and enhances its transcriptional regulation activity via an ABA-mediated signaling pathway. Therefore, this work offers novel target genes for breeding salt- and drought-tolerant plants. Full article

Styrene is an important industrial chemical. Although several studies have reported microbial styrene production, the amount of styrene produced in batch cultures can be increased. In this study, styrene was produced using genetically engineered Escherichia coli. First, we evaluated five types of phenylalanine ammonia lyases (PALs) from Arabidopsis thaliana (AtPAL) and Brachypodium distachyon (BdPAL) for their ability to produce trans-cinnamic acid (Cin), a styrene precursor. AtPAL2-expressing E. coli produced approximately 700 mg/L of Cin and we found that BdPALs could convert Cin into styrene. To assess styrene production, we constructed an E. coli strain that co-expressed AtPAL2 and ferulic acid decarboxylase from Saccharomyces cerevisiae. After a biphasic culture with oleyl alcohol, styrene production and yield from glucose were 3.1 g/L and 26.7% (mol/mol), respectively, which, to the best of our knowledge, are the highest values obtained in batch cultivation. Thus, this strain can be applied to the large–scale industrial production of styrene. Full article