Carbohydrate partitioning from source to sink tissues is essential for plant growth and development.However,in maize(Zea mays L.),the molecular mechanisms by which callose synthase genes regulate this process remain l...Carbohydrate partitioning from source to sink tissues is essential for plant growth and development.However,in maize(Zea mays L.),the molecular mechanisms by which callose synthase genes regulate this process remain largely unexplored.This study demonstrates that mutation of maize callose synthase12(Zm Cals12)results in increased carbohydrate accumulation in photosynthetic leaves but decreased carbohydrate content in sink tissues,leading to plant dwarfing and male sterility.Histochemical β-glucuronidase(GUS)activity assay and m RNA in situ hybridization(ISH)revealed that Zm Cals12 expression mainly occurs in the vascular transport system.Zm Cals12 loss-of-function decreased callose synthase activity and callose deposition in plasmodesmatas(PDs)and surrounding phloem cells(PCs)of the vascular bundle.The drop-and-see(DANS)assay indicated reduced PD permeability in photosynthetic cells and diminished transport competence of leaf veins in Zmcals12 mutants,resulting in decreased symplastic transport.Paraffin section analysis revealed that less-developed vascular cells(VCs)in Zmcals12 mutants likely disrupted sugar transport,contributing to the pleiotropic phenotype.Furthermore,impaired sugar transport inhibited internode development by suppressing auxin(IAA)biosynthesis and signaling in Zmcals12 mutant.These findings elucidate the mechanism by which Zm Cals12-mediated callose deposition and symplastic transport regulate maize growth and development.展开更多
Plasmodesmata(PD)create symplasmic continuity in plant tissues by connecting the cytoplasm of neighboring cells.Molecular movement through PD is important for many processes,including organ development,pathogen defens...Plasmodesmata(PD)create symplasmic continuity in plant tissues by connecting the cytoplasm of neighboring cells.Molecular movement through PD is important for many processes,including organ development,pathogen defense,environmental acclimation,and nutrient allocation.Elucidating the kinetics of PD transport and its regulation is essential for understanding these processes.展开更多
A Nafion 117 complex membrane with low Pd content was prepared. It was found that at room temperature the diffusivity of methanol through this membrane was reduced to one fifth of that through bare Nafion 117 membrane...A Nafion 117 complex membrane with low Pd content was prepared. It was found that at room temperature the diffusivity of methanol through this membrane was reduced to one fifth of that through bare Nafion 117 membrane . The proton conductivity of the modified membrane was also increased, significantly improving the discharge performance of the direct methanol fuel cell(DMFC).展开更多
基金supported by grants from the National Natural Science Foundation of China(31771876)the Biological Breeding Program of State Key Laboratory of Sichuan Agricultural University,China(SKL-ZY202234)the Sichuan Province Science and Technology Program,China(2021YFYZ0011 and 2021YFYZ0017)。
文摘Carbohydrate partitioning from source to sink tissues is essential for plant growth and development.However,in maize(Zea mays L.),the molecular mechanisms by which callose synthase genes regulate this process remain largely unexplored.This study demonstrates that mutation of maize callose synthase12(Zm Cals12)results in increased carbohydrate accumulation in photosynthetic leaves but decreased carbohydrate content in sink tissues,leading to plant dwarfing and male sterility.Histochemical β-glucuronidase(GUS)activity assay and m RNA in situ hybridization(ISH)revealed that Zm Cals12 expression mainly occurs in the vascular transport system.Zm Cals12 loss-of-function decreased callose synthase activity and callose deposition in plasmodesmatas(PDs)and surrounding phloem cells(PCs)of the vascular bundle.The drop-and-see(DANS)assay indicated reduced PD permeability in photosynthetic cells and diminished transport competence of leaf veins in Zmcals12 mutants,resulting in decreased symplastic transport.Paraffin section analysis revealed that less-developed vascular cells(VCs)in Zmcals12 mutants likely disrupted sugar transport,contributing to the pleiotropic phenotype.Furthermore,impaired sugar transport inhibited internode development by suppressing auxin(IAA)biosynthesis and signaling in Zmcals12 mutant.These findings elucidate the mechanism by which Zm Cals12-mediated callose deposition and symplastic transport regulate maize growth and development.
文摘Plasmodesmata(PD)create symplasmic continuity in plant tissues by connecting the cytoplasm of neighboring cells.Molecular movement through PD is important for many processes,including organ development,pathogen defense,environmental acclimation,and nutrient allocation.Elucidating the kinetics of PD transport and its regulation is essential for understanding these processes.
文摘A Nafion 117 complex membrane with low Pd content was prepared. It was found that at room temperature the diffusivity of methanol through this membrane was reduced to one fifth of that through bare Nafion 117 membrane . The proton conductivity of the modified membrane was also increased, significantly improving the discharge performance of the direct methanol fuel cell(DMFC).
