Dynamic Changes in Cell Wall Polysaccharides during Fruit Development and Ripening of Two Contrasting Loquat Cultivars and Associated Molecular Mechanisms

Loquats have drawn much attention due to their essential nutrients and unusual phenology, which fills a market gap in early spring. Fruit firmness (FF) is one of the most important quality attributes. Dynamic changes in FF, cell wall (CW) polysaccharides, CW hydrolase activity, and expression of CW metabolism-related genes during the fruit development and ripening stages of two contrasting loquat cultivars were compared. Although the two cultivars possessed similar FF at the initial fruitlet stage, Dawuxing was significantly firmer than Ninghaibai at all subsequent time points. FF was positively correlated with the contents of covalent-soluble pectin and hemicellulose, activity of peroxidase, and gene expressions of PME, EG, CAD6, and POD; and negatively correlated with the contents of water-soluble pectin, activities of polygalacturonase, endo-glucanase, cellobiohydrolase, and xylanase, and gene expressions of PG, EG2, PAL1, PAL3, and CAD5. Identifying molecular mechanisms underlying the differences in FF is useful for fundamental research and crop improvement in future

Suppressing mechanical dissipation of diamagnetically levitated oscillator via engineering conductive geometry

Diamagnetically levitated oscillators of millimeter and submillimeter size are emerging ultrasensitive sensors for gravitylike force and acceleration measurements. However, improving the levitation capability while keeping mechanical dissipation low remains an open challenge. Here, we propose and experimentally demonstrate an engineering conductive geometry scheme to efficiently reduce the mechanical dissipation of a diamagnetically levitated oscillator made of pyrolytic graphite. We show that with a specially designed conductive geometry, the eddy current damping is reduced, and the reduction factor increases as the engraving pattern being denser. Under high vacuum and room temperature, eddy current damping is the dominant contribution to mechanical dissipation, and we reduce it by a factor of 50 in the experiment. Our work opens up a new way to achieve diamagnetically levitated oscillator with ultralow mechanical dissipation and strong levitation capability, a candidate platform for studying a broad range of fundamental physics

Torque Teno Virus (SANBAN Isolate) ORF2 Protein Suppresses NF-κB Pathways via Interaction with IκB Kinases▿

Since the first discovery of Torque teno virus (TTV) in 1997, many researchers focused on its epidemiology and transcriptional regulation, but the function of TTV-encoded proteins remained unknown. The function of the TTV open reading frame (ORF) in the nuclear factor κB (NF-κB) pathway has not yet been established. In this study, we found for the first time that the TTV ORF2 protein could suppress NF-κB activity in a dose-dependent manner in the canonical NF-κB pathway. By Western blot analysis, we proved that the TTV ORF2 protein did not alter the level of NF-κB expression but prevented the p50 and p65 subunits from entering the nucleus due to the inhibition of IκBα protein degradation. Further immunoprecipitation assays showed that the TTV ORF2 protein could physically interact with IKKβ as well as IKKα, but not IKKγ. Luciferase assays and Western blot experiments showed that the TTV ORF2 protein could also suppress NF-κB activity in the noncanonical NF-κB pathway and block the activation and translocation of p52. Finally, we found that the TTV ORF2 protein inhibited the transcription of NF-κB-mediated downstream genes (interleukin 6 [IL-6], IL-8, and COX-2) through down-regulation of NF-κB. Together, these data indicate that the TTV ORF2 protein suppresses the canonical and noncanonical NF-κB pathways, suggesting that the TTV ORF2 protein may be involved in regulating the innate and adaptive immunity of organisms, contributing to TTV pathogenesis, and even be related to some diseases