H_(2)O_(2)mediates transcriptome reprogramming during Soybean mosaic virus-induced callose deposition in soybean

The main defense response to Soybean mosaic virus(SMV)infection in soybean[Glycine max(L.)Merr.]is thought to be blockage of intercellular virus transport by callose deposition on plasmodesmata.But the specific regulatory mechanism remains largely unknown.In this study,we found that hydrogen peroxide(H_(2)O_(2))signal downstream of NO was associated with the regulation of callose accumulation.Abundant H_(2)O_(2)was produced on the cell membrane and cell wall in the incompatible combination of soybean cultivar Jidou 7 and SMV strain N3,whereas no obvious H_(2)O_(2)was observed in the compatible combination of Jidou 7 and strain SC-8.When H_(2)O_(2)production was inhibited,callose accumulation induced by SMV infection decreased to a level insufficient to restrict virus transport in the incompatible combination.The H_(2)O_(2)-associated transcriptome dynamics of soybean during SMV infection was investigated.Transcriptome and functional analysis using virus-induced gene silencing showed that Gm SEOB and Gm PAP27,two genes regulated by H_(2)O_(2),functioned in resistance by positively regulating the accumulation of callose in response to SMV infection.These results lay a foundation for further research on the signal transduction and molecular regulation of callose deposition during soybean resistance to SMV infection.

Ultrasmall pH-responsive silicon phthalocyanine micelle for selective photodynamic therapy against tumo

Targeted photodynamic therapy(TPDT)based on the photosensitizers responsive for tumor micr oenvironment is promising because of the better anti-tumor effect and less phototoxicity against normal tissue than the traditional PDT.Nanoparticle based stimuli responsive photo-sensitizers have been widely explored for TPDT.Based on the acidic microenvironments in solid tumors,an ultrasmall pH-responsive silicon phthalocyanine nanomicelle(PSN)(smaller than 10 nm)was designed for selective PDT of tumor.PSN had high drug loading efficacy(more than 28%)and exhibited morphological transitions,enhanced fuorescence and improved singlet∞x-ygen yield under acidic environments.PSN was renal dlearable and could rapidly accumulate and be retained at tumor sites,achieving a tumor-inhibiting ffect better than phthalocyanine micelle without pH response.Tumors of mice treated with PSN for PDT were completely ablated without recurrence.Thus,we have developed a phthalocyanine-based pH responsive micelle with excellent tumor targeting ability,which is expected to realize the selective PDT of tumor.

The Functional Characterization of Bat and Human P[3] Rotavirus VP8*s

P[3]rotavirus(RV)has been identified in many species,including human,simian,dog,and bat.Several glycans,including sialic acid,histo-blood group antigens(HBGAs)are reported as RV attachment factors.The glycan binding specificity of different P[3]RV VP8*s were investigated in this study.Human HCR3 A and dog P[3]RV VP8*s recognized glycans with terminal sialic acid and hemagglutinated the red blood cells,while bat P[3]VP8*showed neither binding to glycans nor hemagglutination.However,the bat P[3]VP8*mutant of C189 Y obtained the ability to hemagglutinate the red blood cells,while human P[3]HCR3 A/M2-102 mutants of Y189 C lost the ability.Sequence alignment and structural analysis indicated that residue 189 played an important role in the ligand recognition and may contribute to the cross-species transmission.Structural superimposition exhibited that bat P[3]VP8*model was quite different from the simian P[3]Rhesus rotavirus(RRV)P[3]VP8*,indicating that bat P[3]RV was relatively distinct and partially contributed to the no binding to tested glycans.These results promote our understanding of P[3]VP8*/glycans interactions and the potential transmission of bat/human P[3]RVs,offering more insight into the RV infection and prevalence.

Vortex Smith-Purcell radiation generation with holographic grating

Smith–Purcell radiation(SPR)is the electromagnetic wave generated by free electrons passing above a diffraction grating,and it has played an important role in free-electron light sources and particle accelerators.Orbital angular momentum(OAM)is a new degree of freedom that can significantly promote the capacity of information carried by an electro-magnetic beam.In this paper,we propose an integrable method for generating vortex Smith–Purcell radiation(VSPR),namely,SPR carrying OAM,by having free-electron bunches pass on planar holographic gratings.VSPRs generated by different electron energies,with different topological charges of the OAM,radiation angles,and frequencies are demonstrated numerically.It is also found that,for high-order radiation,the topological charge of the OAM wave will be multiplied by the radiation order.This work introduces a new way to generate SPR with OAM and provides a method to achieve an integratable and tunable free-electron OAM wave source at different frequency regions.

Structural Basis of Glycan Recognition in Globally Predominant Human P[8]Rotavirus

Rotavirus(RV)causes acute gastroenteritis in infants and children worldwide.Recent studies showed that glycans such as histo-blood group antigens(HBGAs)function as cell attachment factors affecting RV host susceptibility and prevalence.P[8]is the predominant RV genotype in humans,but the structural basis of how P[8]RVs interact with glycan ligands remains elusive.In this study,we characterized the interactions between P[8]VP8~*s and glycans which showed that VP8~*,the RV glycan binding domain,recognized both mucin core 2 and H type 1 antigens according to the ELISA-based oligosaccharide binding assays.Importantly,we determined the structural basis of P[8]RV-glycans interaction from the crystal structures of a Rotateq P[8]VP8~*in complex with core 2 and H type 1 glycans at 1.82.3?,respectively,revealing a common binding pocket and similar binding mode.Structural and sequence analysis demonstrated that the glycan binding site is conserved among RVs in the P[Ⅱ]genogroup,while genotype-specific amino acid variations determined different glycan binding preference.Our data elucidated the detailed structural basis of the interactions between human P[8]RVs and different host glycan factors,shedding light on RV infection,epidemiology,and development of anti-viral agents.