Pepper vein yellow virus P0 protein triggers NbHERC3, NbBax, and NbCRR mediated hypersensitive response.

P0 proteins encoded by the pepper vein yellow virus (PeVYV) are pathogenic factors that cause hypersensitive response (HR). However, the host gene expression related to PeVYV P0-induced HR has not been thoroughly studied. Transcriptomic technology was used to investigate the host pathways mediated by the PeVYV P0 protein to explore the molecular mechanisms underlying its function. We found 12,638 differentially expressed genes (DEGs); 6784 and 5854 genes were significantly upregulated and downregulated, respectively. Transcriptomic and reverse-transcription quantitative polymerase chain reaction (RT-qPCR) analyses revealed that salicylic acid (SA) and jasmonic acid (JA) synthesis-related gene expression was upregulated, and ethylene synthesis-related gene expression was downregulated. Ultrahigh performance liquid chromatography-tandem mass spectrometry was used to quantify SA and JA concentrations in Nicotiana benthamiana, and the P0 protein induced SA and JA biosynthesis. We then hypothesized that the pathogenic activity of the P0 protein might be owing to proteins related to host hormones in the SA and JA pathways, modulating host resistance at different times. Viral gene silencing suppression technology was used in N. benthamiana to characterize candidate proteins, and downregulating NbHERC3 (Homologous to E6-AP carboxy-terminus domain and regulator of choromosome condensation-1 dmain protein 3) accelerated cell necrosis in the host. The downregulation of NbCRR reduced cell death, while that of NbBax induced necrosis and curled heart leaves. Our findings indicate that NbHERC3, NbBax, and NbCRR are involved in P0 protein-driven cell necrosis.

Analyzing the kinematics and longitudinal aerodynamics of a four-wing bionic aircraft.

This paper designs a bionic aircraft model equipped with multiple degrees of freedom to study the inertial force equation and the aerodynamic interaction between its forewings and hindwings. Each wing's phase difference angle (PDA) and stroke plane angle (SPA) are independently adjustable. Employing the kinematic equation of a single wing, we establish a model for the inertial force of the four-wing aircraft, validating its accuracy through experimental comparisons. Furthermore, we analyze various combinations of PDA and SPA parameters for the fore- and hindwings to ascertain the most efficient aerodynamic motion modes. Our findings reveal that aerodynamic interference between the fore- and hindwings tends to be unfavorable, predominantly due to the hindwings being exposed to the wake generated by the forewings, hindering their lift-capturing ability. Nevertheless, a specific PDA = 270° (forewing ahead of hindwing 270°) helps mitigate this interference across a wider range of SPA. Interestingly, when the stroke plane aligns parallel to the horizontal direction, asynchronous flapping of the fore- and hindwings, forming a lift mechanism akin to clap-and-fling wings, positively impacts lift. Consequently, staggered flapping of the fore- and hindwings reduces fuselage jitter and alleviates aerodynamic interference through specialized PDA, resulting in a temporary lift enhancement. The purpose of this study is to provide theoretical support for the longitudinal attitude control of four-wing aircraft.

Inhibition mechanism of rice glutelin on extruded starch digestion: From the structural properties of starch and enzyme activity.

To increase the anti-digestion ability of extruded rice starch (ERS), the influence of rice glutelin (RG) on digestive and structural characteristics of ERS were investigated. The resistant starch content increased from 4.49 % to 18.08 % as the RG content increased, while the digestion rate and digestion velocity constant were reduced by the incorporation of RG. Morphological observations showed that ERS was adhered and encapsulated by RG, and the specific area of starch granules were decreased after the addition of RG. The results of XRD and FTIR suggested that the long-range and short-range orders of ERS were improved due to the complexation with RG. The thickness of crystalline of ERS was increased while its amorphous region thickness was reduced by the supplementation with RG. The 1H NMR and 13C NMR data revealed that the branching degree and double helix content of ERS was increased by 46.24 % and 52.67 % when RG content reached to 12 %. Additionally, the addition of RG altered the molecular weight and chain length distribution of ERS. The α-amylase activity and glucoamylase activity was inhibited by RG. These results could provide a valuable basis for the application of RG in extruded rice starchy foods with lower glycemic index.