Ectopic enhancer-enhancer interactions as causal forces driving RNA-directed DNA methylation in gene regulatory regions.

Cis-regulatory elements (CREs) are integral to the spatiotemporal and quantitative expression dynamics of target genes, thus directly influencing phenotypic variation and evolution. However, many of these CREs become highly susceptible to transcriptional silencing when in a transgenic state, particularly when organised as tandem repeats. We investigated the mechanism of this phenomenon and found that three of the six selected flower-specific CREs were prone to transcriptional silencing when in a transgenic context. We determined that this silencing was caused by the ectopic expression of non-coding RNAs (ncRNAs), which were processed into 24-nt small interfering RNAs (siRNAs) that drove RNA-directed DNA methylation (RdDM). Detailed analyses revealed that aberrant ncRNA transcription within the AGAMOUS enhancer (AGe) in a transgenic context was significantly enhanced by an adjacent CaMV35S enhancer (35Se). This particular enhancer is known to mis-activate the regulatory activities of various CREs, including the AGe. Furthermore, an insertion of 35Se approximately 3.5 kb upstream of the AGe in its genomic locus also resulted in the ectopic induction of ncRNA/siRNA production and de novo methylation specifically in the AGe, but not other regions, as well as the production of mutant flowers. This confirmed that interactions between the 35Se and AGe can induce RdDM activity in both genomic and transgenic states. These findings highlight a novel epigenetic role for CRE-CRE interactions in plants, shedding light on the underlying forces driving hypermethylation in transgenes, duplicate genes/enhancers, and repetitive transposons, in which interactions between CREs are inevitable.

Crystallization and electrochemical properties of KxV2O5 nano-ribbons obtained via a solvothermal process as a promising cathode for PIBs.

In this research, a series of K+-intercalated quasi-1D vanadium-based nano-ribbons (KxV2O5 NRs) were synthesized via a facile solvothermal method. The solvation and reductive effects of vanadium oxide precursors (V2O5 powder) on the crystallization and growth of KxV2O5 NRs were studied. Besides, post-heat treatment was performed to improve the crystallinity of KxV2O5 NRs. These KxV2O5 NRs were adopted as active cathodes for potassium-ion batteries (PIBs), whose K+ storage properties were systematically evaluated using various electrochemical methods. The relationship among the morphology, crystallinity, working voltage window and electrochemical reversible K+ storage performance of KxV2O5 NRs was studied and established. Results reveal that KxV2O5-HG, which was prepared via a solvothermal reaction involving a solvation process (using H2O2) and a proper reducing condition (proper dose of glucose) with V2O5 powder as the raw material, would be more beneficial for the reversible storage of K+ when used as the cathode for PIBs compared to other contrast samples. In addition, the enhanced crystallinity and slightly broadened working voltage window of KxV2O5-HG could hinder its long-term cycling stability upon repeated K+ insertions/extractions.

Role of grapevine SEPALLATA-related MADS-box gene VvMADS39 in flower and ovule development.

Seedlessness is one of the most important breeding goals for table grapes; thus, understanding the molecular genetic regulation of seed development and abortion is critical for the development of seedless cultivars. In the present study, we characterized VvMADS39, a class E MADS-box gene of grapevine (Vitis vinifera) orthologous to Arabidopsis SEP2. Heterologous overexpression of VvMADS39 in tomato reduced the fruit and seed size and seed number. Targeted mutagenesis of the homologous SlMADS39 in tomato induced various floral and fruit defects. It could reasonable to suppose that active VvMADS39 expression in "Thompson Seedless" may restrict cellular expansion, resulting in the development of smaller fruits and seeds, VvMADS39 may play a role in the regulation of ovule development in grapevine and contributes to seedless fruit formation. In contrast, VvMADS39 suppression in "Red Globe" was associated with enhanced histone H3 lysine 27 trimethylation in the promoter region of VvMADS39, allowing normal ovule and fruit development; Meanwhile, VvMADS39 interacts with VvAGAMOUS, and the activity of the VvMADS39-VvAGAMOUS dimer to induce integument development requires the activation and maintenance of VvINO expression. The synergistic cooperation between VvMADS39 and related proteins plays an important role in maintaining floral meristem characteristics, and fruit and ovule development.

VqWRKY56 interacts with VqbZIPC22 in grapevine to promote proanthocyanidin biosynthesis and increase resistance to powdery mildew.

Powdery mildew (PM) is a severe fungal disease of cultivated grapevine world-wide. Proanthocyanidins (PAs) play an important role in resistance to fungal pathogens; however, little is known about PA-mediated PM resistance in grapevine. We identified a WRKY transcription factor, VqWRKY56, from Vitis quinquangularis, the expression of which was significantly induced by PM. Overexpression (OE) of VqWRKY56 in Vitis vinifera increased PA content and reduced susceptibility to PM. Furthermore, the transgenic plants showed more cell death and increased accumulation of salicylic acid and reactive oxygen species. Transient silencing of VqWRKY56 in V. quinquangularis and V. vinifera reduced PA accumulation and increased the susceptibility to PM. VqWRKY56 interacted with VqbZIPC22 in vitro and in planta. The protein VqWRKY56 can bind to VvCHS3, VvLAR1, and VvANR promoters, and VqbZIPC22 can bind to VvANR promoter. Co-expression of VqWRKY56 and VqbZIPC22 significantly increased the transcript level of VvCHS3, VvLAR1, and VvANR genes. Finally, transient OE of VqbZIPC22 in V. vinifera promoted PA accumulation and improved resistance to PM, while transient silencing in V. quinquangularis had the opposite effect. Our study provides new insights into the mechanism of PA regulation by VqWRKY56 in grapevine and provides a basis for further metabolic engineering of PA biosynthesis to improve PM resistance.

Traditional Chinese Medicine Compound (Tongxinluo) and Clinical Outcomes of Patients With Acute Myocardial Infarction: The CTS-AMI Randomized Clinical Trial.

Importance: Tongxinluo, a traditional Chinese medicine compound, has shown promise in in vitro, animal, and small human studies for myocardial infarction, but has not been rigorously evaluated in large randomized clinical trials. Objective: To investigate whether Tongxinluo could improve clinical outcomes in patients with ST-segment elevation myocardial infarction (STEMI). Design, Setting, and Participants: Randomized, double-blind, placebo-controlled clinical trial was conducted among patients with STEMI within 24 hours of symptom onset from 124 hospitals in China. Patients were enrolled from May 2019 to December 2020; the last date of follow-up was December 15, 2021. Interventions: Patients were randomized 1:1 to receive either Tongxinluo or placebo orally for 12 months (a loading dose of 2.08 g after randomization, followed by the maintenance dose of 1.04 g, 3 times a day), in addition to STEMI guideline-directed treatments. Main Outcomes and Measures: The primary end point was 30-day major adverse cardiac and cerebrovascular events (MACCEs), a composite of cardiac death, myocardial reinfarction, emergent coronary revascularization, and stroke. Follow-up for MACCEs occurred every 3 months to 1 year. Results: Among 3797 patients who were randomized, 3777 (Tongxinluo: 1889 and placebo: 1888; mean age, 61 years; 76.9% male) were included in the primary analysis. Thirty-day MACCEs occurred in 64 patients (3.4%) in the Tongxinluo group vs 99 patients (5.2%) in the control group (relative risk [RR], 0.64 [95% CI, 0.47 to 0.88]; risk difference [RD], -1.8% [95% CI, -3.2% to -0.6%]). Individual components of 30-day MACCEs, including cardiac death (56 [3.0%] vs 80 [4.2%]; RR, 0.70 [95% CI, 0.50 to 0.99]; RD, -1.2% [95% CI, -2.5% to -0.1%]), were also significantly lower in the Tongxinluo group than the placebo group. By 1 year, the Tongxinluo group continued to have lower rates of MACCEs (100 [5.3%] vs 157 [8.3%]; HR, 0.64 [95% CI, 0.49 to 0.82]; RD, -3.0% [95% CI, -4.6% to -1.4%]) and cardiac death (85 [4.5%] vs 116 [6.1%]; HR, 0.73 [95% CI, 0.55 to 0.97]; RD, -1.6% [95% CI, -3.1% to -0.2%]). There were no significant differences in other secondary end points including 30-day stroke; major bleeding at 30 days and 1 year; 1-year all-cause mortality; and in-stent thrombosis (<24 hours; 1-30 days; 1-12 months). More adverse drug reactions occurred in the Tongxinluo group than the placebo group (40 [2.1%] vs 21 [1.1%]; P = .02), mainly driven by gastrointestinal symptoms. Conclusions and Relevance: In patients with STEMI, the Chinese patent medicine Tongxinluo, as an adjunctive therapy in addition to STEMI guideline-directed treatments, significantly improved both 30-day and 1-year clinical outcomes. Further research is needed to determine the mechanism of action of Tongxinluo in STEMI. Trial Registration: ClinicalTrials.gov Identifier: NCT03792035.

Improvement of RNA In Situ Hybridisation for Grapevine Fruits and Ovules.

The European grapevine (Vitis vinifera L.) is one of the world's most widely cultivated and economically important fruit crops. Seedless fruits are particularly desired for table grapes, with seedlessness resulting from stenospermocarpy being an important goal for cultivar improvement. The establishment of an RNA in situ hybridisation (ISH) system for grape berries and ovules is, therefore, important for understanding the molecular mechanisms of ovule abortion in stenospermocarpic seedless cultivars. We improved RNA in situ hybridisation procedures for developing berries and ovules by targeting two transcription factor genes, VvHB63 and VvTAU, using two seeded varieties, 'Red Globe' and 'Pinot Noir', and two seedless cultivars, 'Flame Seedless' and 'Thompson Seedless'. Optimisation focused on the time of proteinase K treatment, probe length, probe concentration, hybridisation temperature and post-hybridisation washing conditions. The objectives were to maximise hybridisation signals and minimise background interference, while still preserving tissue integrity. For the target genes and samples tested, the best results were obtained with a pre-hybridisation proteinase K treatment of 30 min, probe length of 150 bp and concentration of 100 ng/mL, hybridisation temperature of 50 °C, three washes with 0.2× saline sodium citrate (SSC) solution and blocking with 1% blocking reagent for 45 min during the subsequent hybridisation. The improved ISH system was used to study the spatiotemporal expression patterns of genes related to ovule development at a microscopic level.

Transcription Factor MdbHLH093 Enhances Powdery Mildew Resistance by Promoting Salicylic Acid Signaling and Hydrogen Peroxide Accumulation.

Powdery mildew is an apple disease caused by the obligate trophic fungus Podosphaera leucotricha. Basic helix-loop-helix (bHLH) transcription factors play important roles in plant development and stress responses, and they have been widely studied in model plants such as Arabidopsis thaliana. However, their role in the stress response of perennial fruit trees remains unclear. Here, we investigated the role of MdbHLH093 in the powdery mildew of apples. The expression of MdbHLH093 was significantly induced during the infection of apples with powdery mildew, and the allogenic overexpression of MdbHLH093 in A. thaliana enhanced the resistance to powdery mildew by increasing the accumulation of hydrogen peroxide (H2O2) and activating the salicylic acid (SA) signaling pathway. The transient overexpression of MdbHLH093 in apple leaves increased the resistance to powdery mildew. Conversely, when MdbHLH093 expression was silenced, the sensitivity of apple leaves to powdery mildew was increased. The physical interaction between MdbHLH093 and MdMYB116 was demonstrated by yeast two-hybrid, bi-molecular fluorescence complementation, and split luciferase experiments. Collectively, these results indicate that MdbHLH093 interacts with MdMYB116 to improve apple resistance to powdery mildew by increasing the accumulation of H2O2 and activating the SA signaling pathway, as well as by providing a new candidate gene for resistance molecular breeding.

The Impact of Elsinoë ampelina Infection on Key Metabolic Properties in Vitis vinifera 'Red Globe' Berries via Multiomics Approaches.

Grape anthracnose caused by Elsinoë ampelina (Shear) is one of the most serious fungal diseases that lead to the quality reduction and yield losses of grape (Vitis vinifera 'Red Globe') berries. In the present study, metabolome and transcriptome analyses were conducted using grape berries in the field after infection with E. ampelina at 7, 10, and 13 days to identify the metabolic properties of berries. In total, 132 metabolites with significant differences and 6,877 differentially expressed genes were detected and shared by three comparisons. The analyses demonstrated that phenylpropanoid, flavonoid, stilbenoid, and nucleotide metabolisms were enriched in E. ampelina-infected grape berries but not amino acid metabolism. Phenolamide, terpene, and polyphenole contents also accumulated during E. ampelina infection. The results provided evidence of the enhancement of secondary metabolites such as resveratrol, α-viniferin, ε-viniferin, and lignins involved in plant defense. The results showed the plant defense-associated metabolic reprogramming caused by E. ampelina infection in grape berry and provided a global metabolic mechanism under E. ampelina stimulation.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Ultrastructural Observations of Botrytis cinerea and Physical Changes in Resistant and Susceptible Grapevines.

The necrotrophic fungus Botrytis cinerea is a major threat to grapevine cultivation worldwide. Here, a highly resistant Chinese wild grapevine, Vitis amurensis 'Shuangyou' (SY), and the susceptible V. vinifera 'Red Globe' (RG) were selected for study, and their pathogenic infection and biochemical responses to B. cinerea were evaluated. The results revealed more trichomes on and a thicker cuticle for leaves of SY than RG under scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Both SEM and TEM also showed that conidial germination, appressorium formation, and hyphal development of B. cinerea were delayed on the leaves of resistant SY. Fewer infected hyphae were also observed in leaves of resistant SY when compared with susceptible RG. The infected leaves of resistant SY harbored higher levels of cellulase and pectinase activity during the early infection stages of B. cinerea at 4 h postinoculation (hpi), and higher glucanase and chitinase activity were maintained in the inoculated leaves of SY from 4 through 18 hpi. Lignin was deposited in the infected leaves of susceptible RG but not in resistant SY. Taken together, these results provide insights into the ultrastructural characterizations and physical changes in resistant and susceptible grapevines.

Analysis of Grapevine's Somatic Embryogenesis Receptor Kinase (SERK) Gene Family: VqSERK3/BAK1 Overexpression Enhances Disease Resistance.

The somatic embryogenesis receptor kinase (SERK) gene family has been intensively studied in several plant species. Here we confirmed the existence of five SERK genes in grapevine (Chinese wild grapevine Vitis quinquangularis) and named them VqSERK1, VqSERK2, VqSERK3, VqSERK4, and VqSERK5. Analysis of the predicted structures of these SERK proteins revealed they include a signal peptide domain, a leucine zipper domain, a Ser-Pro-Pro domain, a single transmembrane domain, different leucine-rich repeats, and an intracellular kinase activity domain. The SERK genes of grapevine showed different gene expression patterns when treated with powdery mildew (Erysiphe necator) and hormones (salicylic acid, jasmonic acid, abscisic acid, and ethylene). Subcellular localization assays confirmed that VqSERK family proteins localized to the cell membrane. Moreover, we cloned the SERK3/BAK1 gene from the Chinese wild grapevine V. quinquangularis clone 'Shang-24'. Heterologous VqSERK3/BAK1 expression in the Arabidopsis bak1-4 mutant lines restored control of cell death, increased resistance to powdery mildew, and strengthened stomatal immunity. Our work may provide the foundation for further studies of SERK genes for pathogen resistance and hormone treatment in grapevine.

Infrared Vein Imaging for Insertion of Peripheral Intravenous Catheter for Patients Requiring Isolation for Severe Acute Respiratory Syndrome Coronavirus 2 Infection: A Nonrandomized Clinical Trial.

INTRODUCTION: Establishing intravenous access is essential but may be difficult to achieve for patients requiring isolation for severe acute respiratory syndrome coronavirus 2 infection. This study aimed to investigate the effectiveness of an infrared vein visualizer on peripheral intravenous catheter therapy in patients with coronavirus disease 2019. METHODS: A nonrandomized clinical trial was performed. In total, 122 patients with coronavirus disease 2019 who required peripheral intravenous cannulation were divided into 2 groups with 60 in the control group and 62 in the intervention group. A conventional venipuncture method was applied to the control group, whereas an infrared vein imaging device was applied in the intervention group. The first attempt success rate, total procedure time, and patients' satisfaction score were compared between the 2 groups using chi-square, t test, and z test (also known as Mann-Whitney U test) statistics. RESULTS: The first attempt success rate in the intervention group was significantly higher than that of control group (91.94% vs 76.67%, ꭓ2 = 5.41, P = .02). The procedure time was shorter in the intervention group (mean [SD], 211.44 [68.58] seconds vs 388.27 [88.97] seconds, t = 12.27, P < .001). Patients from the intervention group experienced a higher degree of satisfaction (7.5 vs 6, z = -3.31, P < .001). DISCUSSION: Peripheral intravenous catheter insertion assisted by an infrared vein visualizer could improve the first attempt success rate of venipuncture, shorten the procedure time, and increase patients' satisfaction.

Transcriptome Analysis of the Grape-Elsinoë ampelina Pathosystem Reveals Novel Effectors and a Robust Defense Response.

Elsinoë ampelina is an ascomycetous fungus that causes grape anthracnose, a potentially devastating disease worldwide. In this study, a dual RNA-seq analysis was used to simultaneously monitor the fungal genes related to pathogenesis and grape genes related to defense during the interaction at 2, 3, 4, and 5 days postinoculation. Consistent with their potential roles in pathogenicity, genes for carbohydrate-active enzymes, secondary metabolite synthesis, pathogen-host interaction, and those encoding secreted proteins are upregulated during infection. Based on Agrobacterium tumefaciens-mediated transient assays in Nicotiana benthamiana, we further showed that eight and nine candidate effectors, respectively, suppressed BAX- and INF1-mediated programmed cell death. The host response was characterized by the induction of multiple defense systems against E. ampelina, including synthesis of phenylpropanoids, stilbenes, and terpenoid biosynthesis, cell-wall modifications, regulation by phytohormones, and expression of defense-related genes. Together, these findings offer new insights into molecular mechanisms underlying the grape-E. ampelina interaction.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Genome-wide identification and expression analysis of the B-box transcription factor gene family in grapevine (Vitis vinifera L.).

BACKGROUND: B-box (BBX) zinc-finger transcription factors play important roles in plant growth, development, and stress response. Although these proteins have been studied in model plants such as Arabidopsis thaliana or Oryza sativa, little is known about the evolutionary history or expression patterns of BBX proteins in grapevine (Vitis vinifera L.). RESULTS: We identified a total of 25 VviBBX genes in the grapevine genome and named them according to the homology with Arabidopsis. These proteins were classified into five groups on the basis of their phylogenetic relationships, number of B-box domains, and presence or absence of a CCT domain or VP motif. BBX proteins within the same group showed similar exon-intron structures and were unevenly distributed in grapevine chromosomes. Synteny analyses suggested that only segmental duplication events contributed to the expansion of the VviBBX gene family in grapevine. The observed syntenic relationships between some BBX genes from grapevine and Arabidopsis suggest that they evolved from a common ancestor. Transcriptional analyses showed that the grapevine BBX genes were regulated distinctly in response to powdery mildew infection and various phytohormones. Moreover, the expression levels of a subset of BBX genes in ovules were much higher in seedless grapevine cultivars compared with seeded cultivars during ovule development, implying a potential role in seed abortion. Additionally, VviBBX8, VquBBX15a and VquBBX29b were all located in the nucleus and had transcriptional activity except for VquBBX29b. CONCLUSIONS: The results of this study establish the genome-wide analysis of the grapevine BBX family and provide a framework for understanding the biological roles of BBX genes in grapevine.

The co-expression of genes involved in seed coat and endosperm development promotes seed abortion in grapevine.

MAIN CONCLUSION: The seed coat gene VviAGL11 coordinates with endosperm development genes FIS2, PHERESE1 and IKU2 and functions as the key regulator in seed development and abortion processes in grapevine. Seed development is essential for the reproduction of flowering plants. Seed abortion is a specific characteristic that produces seedless berries and is often observed in cultivated grapevines. Although seedlessness is an important trait for table and dried grapevine production, the mechanism of seed abortion remains poorly understood. This research aimed to analyze the co-expression of the seed coat development gene VviAGL11 and the endosperm development genes FERTILIZATION INDEPENDENT SEED2 (FIS2), PHERESE1 and HAIKU2 (IKU2) that regulate seedless fruit development in grapevine. The transcript levels of VviAGL11, FIS2, PHERESE1 and IKU2 all decreased during seed abortion in the seedless grape 'Thompson Seedless' plants, compared to those of the seeded grape 'Pinot Noir'. The transcript levels of the salicylic acid (SA)-dependent defense response genes EDS1, NPR1, NDR1 and SID2 were higher in 'Thompson Seedless' than 'Pinot Noir' during seed development. Also, WRKY3, WRKY6 and WRKY52, which participate in the SA pathway, were higher expressed in 'Thompson Seedless' than in 'Pinot Noir', indicating that SA-dependent defense responses may regulate seed abortion. The genes related to synthesis and metabolism of gibberellic acid (GA) and abscisic acid (ABA) also showed differential expression between 'Thompson Seedless' and 'Pinot Noir'. Exogenous applications of plant growth regulators (PGRs) to inflorescences of three stenospermocarpy grapevines before flowering showed that GA3 was critical prominently in seed development. Therefore, the co-expression of seed coat and endosperm development-related genes, SA pathway genes, and genes for the synthesis and metabolism of GA3 together enhance seed abortion in seedless grapes.

Pathogenesis and Immune Response in Resistant and Susceptible Cultivars of Grapevine (Vitis spp.) Against Elsinoë ampelina Infection.

Elsinoë ampelina is the main cause of grape anthracnose, and the majority of grapevine cultivars are susceptible to this fungus. Some Chinese wild grape cultivars are resistant, however. It is therefore apt to compare the pathogenesis and immune responses in susceptible and resistant cultivars of grapevine to explore the detailed molecular and biochemical mechanisms of resistance to this fungus. In this study, ultrastructural and histopathological observations were used to demonstrate the resistance responses to E. ampelina in the resistant Chinese wild cultivar Vitis quinquangularis clone 'Shang-24' and the susceptible cultivars V. davidii 'Tangwei' and V. vinifera 'Thompson Seedless'. Seventy-two hours postinoculation (hpi) with E. ampelina, brown necrotic spots were clearly visible on the leaves of the susceptible 'Tangwei' and 'Thompson Seedless'. The infection was characterized by rapid colonization of the host cells by hyphae and massive spread of the pathogen in the intercellular spaces, ultimately leading to host cell collapse, cuticle dissolution, and extensive hyphal growth. In the resistant clone 'Shang-24', the conidia were lysed, a large quantity of electronically dense matter appeared, the hyphal growth was suppressed, and the host cells remained intact. In addition, six genes associated with disease resistance were differentially expressed in the susceptible and resistant cultivars. These disease-related genes were significantly up-regulated following infection with E. ampelina. This study illustrates the differences in infection and colonization of E. ampelina in resistant and susceptible grape leaves.

Grape Transcriptome Response to Powdery Mildew Infection: Comparative Transcriptome Profiling of Chinese Wild Grapes Provides Insights Into Powdery Mildew Resistance.

Erysiphe necator, the fungal pathogen of grape powdery mildew disease, poses a great threat to the grape market and the wine industry. To better understand the molecular basis of grape responses to E. necator, we performed comparative transcriptome profiling on two Chinese wild grape accessions with varying degrees of resistance to E. necator. At 6-, 24-, and 96-h postinoculation of E. necator, 2,856, 2,678, and 1,542 differentially expressed genes (DEGs) were identified in the susceptible accession Vitis pseudoreticulata 'Hunan-1', and at those same time points, 1,921, 2,498, and 3,249 DEGs, respectively, were identified in the resistant accession V. quinquangularis 'Shang-24'. 'Hunan-1' had a substantially larger fraction of down-regulated genes than 'Shang-24' at every infection stage. Analysis of DEGs revealed that up-regulated genes were mostly associated with defense response and disease resistance-related metabolite biosynthesis, and such signaling genes were significantly suppressed in 'Hunan-1'. Interestingly, fatty acid biosynthesis- and elongation-related genes were suppressed by the fungus in the 'Shang-24' accession but somehow induced in the 'Hunan-1' accession, consistent with the concept that E. necator is likely to be a fatty acid auxotroph that requires lipids from the host. Moreover, genes involved in biosynthesis and signaling of phytohormones, such as jasmonic acid and cytokinin, as well as genes encoding protein kinases and nucleotide-binding domain leucine-rich repeat proteins, differentially responded to E. necator in the two wild grapes. The variation of gene regulation associated with nutrient uptake by the fungus and with signaling transduction and pathogen recognition suggests a multilayered regulatory network that works in concert to assist in the establishment of fungal pathogen infections.

Overexpression of the Apple (Malus × domestica) MdERF100 in Arabidopsis Increases Resistance to Powdery Mildew.

APETALA2/ETHYLENE RESPONSIVE FACTOR (AP2/ERF) transcription factors play important roles in plant development and stress response. Although AP2/ERF genes have been extensively investigated in model plants such as Arabidopsis thaliana, little is known about their role in biotic stress response in perennial fruit tree crops such as apple (Malus × domestica). Here, we investigated the role of MdERF100 in powdery mildew resistance in apple. MdERF100 localized to the nucleus but showed no transcriptional activation activity. The heterologous expression of MdERF100 in Arabidopsis not only enhanced powdery mildew resistance but also increased reactive oxygen species (ROS) accumulation and cell death. Furthermore, MdERF100-overexpressing Arabidopsis plants exhibited differential expressions of genes involved in jasmonic acid (JA) and salicylic acid (SA) signaling when infected with the powdery mildew pathogen. Additionally, yeast two-hybrid and bimolecular fluorescence complementation assays confirmed that MdERF100 physically interacts with the basic helix-loop-helix (bHLH) protein MdbHLH92. These results suggest that MdERF100 mediates powdery mildew resistance by regulating the JA and SA signaling pathways, and MdbHLH92 is involved in plant defense against powdery mildew. Overall, this study enhances our understanding of the role of MdERF genes in disease resistance, and provides novel insights into the molecular mechanisms of powdery mildew resistance in apple.

Genome Sequence Resource for Elsinoë ampelina, the Causal Organism of Grapevine Anthracnose.

Elsinoë ampelina is an ascomycetous fungus that causes grape anthracnose, a potentially devastating disease worldwide. Here, we report a 28.29 Mb high-quality genome sequence of E. ampelina YL-1 that encodes 8,057 predicted protein-coding genes and represents the first sequenced genome assembly of E. ampelina. This study adds to the current genomic resources for the genus Elsinoë and paves the way for research on comparative genomic studies, E. ampelina-grape interactions, and improvement of management strategies.

The Endophytic Fungus Albifimbria verrucaria from Wild Grape as an Antagonist of Botrytis cinerea and Other Grape Pathogens.

Gray mold, caused by Botrytis cinerea, is one of the most prevalent fungal diseases in table and wine grapes, affecting grape quality and yields. In this study, we isolated several endophytic fungi, including Alternaria alternata, Bipolaris cynodontis, Phoma sp., and Albifimbria verrucaria, from leaves of Amur grape (Vitis amurensis) cultivar Shuangyou and investigated their biocontrol activity against B. cinerea. In vitro dual assay showed that A. verrucaria isolate SYE-1 inhibited growth of B. cinerea. The isolate also had a wide range of biocontrol activity against Lasiodiplodia theobromae and Elsinoë ampelina. Mycelial growth and conidium germination of B. cinerea were significantly inhibited by metabolites of A. verrucaria in agar plates and culture extracts of A. verrucaria from liquid culture. The isolate produced a total chitinase activity of 0.4 U/ml after incubation for 10 days in Czapek's liquid medium. In addition, application of culture extracts of A. verrucaria prior to B. cinerea inoculation significantly reduced disease severity on grape leaves of the susceptible cultivar Red Globe. Taken together, our results indicate that A. verrucaria has potential as a biocontrol agent to control grape gray mold.

Development of Electronic Nose for Qualitative and Quantitative Monitoring of Volatile Flammable Liquids.

A real-time electric nose (E-nose) with a metal oxide sensor (MOS) array was developed to monitor 5 highly flammable liquids (ethanol, tetrahydrofuran, turpentine, lacquer thinner, and gasoline) in this work. We found that temperature had a significant impact on the test results and temperature control could efficiently improve the performance of our E-nose. The results of our qualitative analysis showed that principal component analysis (PCA) could not efficiently distinguish these samples compared to a back-propagation artificial neural network (BP-ANN) which had a 100% accuracy rate on the test samples. Quantitative analysis was performed by regression analysis and the average errors were 9.1%-18.4%. In addition, through anti-interference training, the E-nose could filter out the potential false alarm caused by mosquito repellent, perfume and hair jelly.