First Report of Root Rot Caused by Fusarium oxysporum on Aralia elata in China.

Aralia elata (Miq.) Seem., is grown for its medicinal and nutritional properties in northeastern China. The tender shoots are used as wild vegetables. The plant saponin components have antioxidant and neuroprotective activities, and are used for the treatment of chronic disease (Xia et al. 2021). In July 2021, root rot disease was observed in five-year-old A. elata plants in Qingyuan County (41°91' N, 124°59' E), Liaoning Province, China. The incidence of roots rot was approximately 50% in old fields, with the leaves of the infected plants appearing chlorotic and wilting. The lesions on the taproots were dark brown and soft, with degraded internal organization. Leading edge of necrotic tissue from symptomatic roots was cut 5×5×3 mm, placed in 75% ethanol for 30 s, and then in 3% sodium hypochlorite for 2 min. After three rinses in sterile distilled water, the samples were dried on sterile filter paper before plating on potato dextrose agar (PDA) and incubation at 25℃. Monosporic cultures were obtained by the collection of single spores from individual isolates. After 7 days on PDA, mycelia in the colonies appeared cottony and pink, white, or purple in color, while their undersides were pink and white. Spore characteristics were evaluated after transfer to carnation leaf agar (CLA) and incubation for 20 days (Zhang et al. 2021). The macroconidia were falciform, slightly curved or straight, two to five septate, and 20.57 to 33.75 × 3.62 to 6.11 µm (n=40). The microconidia were ovoid or oval, zero to one septate, and 5.12 to 13.53 × 3.04 to 4.79 µm (n=40). Chlamydospores were globose to subglobose, intercalary or terminal, with an average diameter of 13.76 µm (n=40).To identify the pathogen, the internal transcribed spacer (ITS) region, large subunit (LSU) ribosomal DNA, and translation elongation factor 1 alpha (TEF-1α) gene were amplified using the respective primer pairs ITS1/ITS4, LR0R/LR7, and EF1-728F/EF1-986R (Cheng et al. 2020; Fu et al. 2019). Comparisons with GenBank, the sequences of ITS, LSU, and TEF-1 had 99 to 100% homology with Fusarium oxysporum (accessions numbers- MH707084, OQ380519, and GU250609, respectively). The sequences were deposited in GenBank: OP482273 (ITS), OP491955 (LSU), and OP503498 (TEF-1α). Maximum likelihood phylogeny of the identified sequences using MEGA-X software indicated that the isolate represented F. oxysporum. The taproots of 30 one-year-old A. elata were washed and inoculated with 1×106/ml of the conidial suspension for two hours, and another 30 used as controls with sterile water. After planting in sterilized forest soil in flowerpots (36×30 cm), the plants were grown in a greenhouse for two weeks at 25℃ with 14 h of light. It was found that 50% of the roots showed typical root rot symptoms, while the controls were asymptomatic. The pathogenicity test was repeated three times, and reisolation of F. oxysporum from the roots fulfilled Koch's postulates. This is the first report of root rot in A. elata caused by F. oxysporum in China and indicates the necessity for suitable management strategies to protect A. elata production. References: Cheng, Y., et al. 2020. Plant Dis. 104:3072. Fu, R., et al. 2019. Plant Dis. 103:1426. Xia, W., et al. 2021. Mini-Rev Med Chem. 21:2567. Zhang, X. M., et al. 2021. Plant Dis. 105:1223.

PHLDA1 knockdown alleviates mitochondrial dysfunction and endoplasmic reticulum stress-induced neuronal apoptosis via activating PPARγ in cerebral ischemia-reperfusion injury.

Mitochondrial dysfunction and endoplasmic reticulum (ER) stress occur in ischemic stroke. The disruption of these two organelles can directly lead to cell death through various signaling pathways. Thus, investigation of the associated molecular mechanisms in cerebral ischemia is a prerequisite for stroke treatment. Pleckstrin homology-like domain family A member 1 (PHLDA1) is a multifunctional protein that can modulate mitochondrial function and ER stress in cardiomyocyte and cancer cells. This work studied the role of PHLDA1 in cerebral ischemic/reperfusion (I/R) injury and explored the underlying mechanisms associated with mitochondrial functions and ER stress. Middle cerebral artery occlusion/reperfusion (MCAO/R)-treated mice and oxygen-glucose deprivation/reoxygenation (OGD/R)-stimulated neurons were used as I/R models in vivo and in vitro, respectively. PHLDA1 was upregulated in ischemic penumbra of MCAO/R-induced mice and OGD/R-exposed neurons. In vitro, PHLDA1 knockdown protected neurons from OGD/R-induced apoptosis. In vivo, PHLDA1 silencing facilitated functional recovery and reduced cerebral infarct volume. Mechanistically, PHLDA1 knockdown promoted PPARγ nuclear translocation, which may mediate the effects on reversion of mitochondrial functions and alleviation of ER stress. In summary, PHLDA1 knockdown alleviates neuronal ischemic injuries in mice. PPARγ activation and mitochondrial dysfunction and endoplasmic reticulum stress attenuation are involved in the underlying mechanisms.

Biomechanical Energy Harvesters Based on Ionic Conductive Organohydrogels via the Hofmeister Effect and Electrostatic Interaction.

The recent use of cryoprotectant replacement method for solving the easy drying problem of hydrogels has attracted increasing research interest. However, the conductivity decrease of organohydrogels due to the induced insulating solvent limited their electronic applications. Herein, we introduce the Hofmeister effect and electrostatic interaction to generate hydrogen and sodium bonds in the hydrogel. Combined with its double network, an effective charge channel that will not be affected by the solvent replacement, is therefore built. The developed organohydrogel-based single-electrode triboelectric nanogenerator (OHS-TENG) shows low conductivity decrease (one order) and high output (1.02-1.81 W/m2), which is much better than reported OHS-TENGs (2-3 orders, 41.2-710 mW/m2). Moreover, replacing water with glycerol in the hydrogel enables the device to exhibit excellent long-term stability (four months) and temperature tolerance (-50-100 °C). The presented strategy and mechanism can be extended to common organohydrogel systems aiming at high performance in electronic applications.

Electrodeposition of (111)-oriented and nanotwin-doped nanocrystalline Cu with ultrahigh strength for 3D IC application.

The mechanical performance of electroplated Cu plays a crucial role in next-generation Cu-to-Cu direct bonding for the three-dimension integrated circuit (3D IC). This work reports direct-current electroplated (111)-preferred and nanotwin-doped nanocrystalline Cu, of which strength is at the forefront performance compared with all reported electroplated Cu materials. Tension and compression tests are performed to present the ultrahigh ultimate strength of 977 MPa and 1158 MPa, respectively. The microstructure of nanoscale Cu grains with an average grain size around 61 nm greatly contributes to the ultrahigh strength as described by the grain refinement effect. A gap between the obtained yield strength and the Hall-Petch relationship indicates the presence of extra strengthening mechanisms. X-ray diffraction and transmission electron microscopy analysis identify the highly (111) oriented texture and sporadic twins with optimum thicknesses, which can effectively impede intragranular dislocation movements, thus further advance the strength. Via filling capability and high throughput are also demonstrated in the patterned wafer plating. The combination of ultrahigh tensile/compressive strength, (111) preferred texture, superfilling capability and high throughput satisfies the critical requirement of Cu interconnects plating technology towards the industrial manufacturing in advanced 3D IC packaging application.

The Two-Component System DcuS-DcuR Is Involved in Virulence and Stress Tolerance in the Poplar Canker Bacterium Lonsdalea populi.

The gram-negative bacterium Lonsdalea populi causes an emerging poplar (Populus × euramericana) canker resulting in severe losses to poplar production in China and Europe. Two-component signal transduction systems play important roles in the regulation of virulence and stress responses in phytopathogenic bacteria. We identified a two-component pair (Lqp2625-Lqp2624) in L. populi, highly homologous to DcuS-DcuR of Escherichia coli. Mutants lacking DcuS or DcuR displayed normal growth while their virulence on poplar twigs was impaired. An inability to produce flagella indicated that DcuS and DcuR are involved in biofilm formation and swimming motility. Moreover, the loss of DcuS or DcuR led to increased sensitivity to oxidative stress and chloramphenicol through downregulation of genes associated with catalases and the multidrug efflux pump, suggesting that the two-component pair contributes to cellular adaptation to oxidative and antibiotic stresses. We identified key domains and putative phosphorylation sites important for virulence and stress responses. Our findings reveal the functions of DcuS-DcuR in virulence and stress responses in L. populi and provide increasing evidence that two-component systems are crucial during the infection process and stress adaptation in bacteria.