To mutagenize two conserved CCCT and PTK motifs in the central domain of Chinese strain of potato Y potyvirus (PVY-C) helper component proteinase (HC-Pro), four mutants of HC-Pro gene were obtained by PCR and site-dir...To mutagenize two conserved CCCT and PTK motifs in the central domain of Chinese strain of potato Y potyvirus (PVY-C) helper component proteinase (HC-Pro), four mutants of HC-Pro gene were obtained by PCR and site-directed mutagenesis, and then were inserted into the constitutive expression vector pBin438. Leaves from tobacco (Nicotiana tabacum L. cv. K326) were transformed with these four plant expression plasmids by Agrobacterium-mediated transformation, respectively. Southern and Western blotting analyses showed that these four mutants were integrated into tobacco genomic DNA and could express the corresponding proteins in most of die transgenic plants. The challenge of transgenic plants with potato X potexvirus (PVX) revealed that the expression products of PVY-C HC-Pro mutants in transgenic plants greatly abolished functions of HC-Pro in enhancing the accumulation and pathogenicity of PVX, indicating that CCCT and PTK motifs of HC-Pro were required for PVX/PVY synergism. Meanwhile, the results demonstrated that PVY-C HC-Pro had a function in accelerating the long-distance movement of PVX in these transgenic plants for the first time.展开更多
Novel headstand pyrocarbon cones （HPCs） with hollow structure were developed on the surfaces of pyrocarbon layers of the carbon/carbon （C/C） composites at 650-750 °C by the electromagnetic-field-assisted chem...Novel headstand pyrocarbon cones （HPCs） with hollow structure were developed on the surfaces of pyrocarbon layers of the carbon/carbon （C/C） composites at 650-750 °C by the electromagnetic-field-assisted chemical vapor deposition in the absence of catalysts. The fine microstructures of the HPCs were characterized by high-resolution transmission electron microscopy. The results show that the textural features of the HPCs directly transfer from turbostratic structure in roots to a well-ordered high texture in stems. And the degree of high texture ordering decreases gradually from the stem to the tail of the HPCs. The formation mechanism of the HPCs was inferred as the comprehensive effect of polarization induction on electromagnetic fields and particle-filler property under disruptive discharge.展开更多
In this paper, the generative approach utilizes recursion to generate process sequence for a part, and then match detail procedure design and select process equipment. A set of recursive formulas are found. Finally ...In this paper, the generative approach utilizes recursion to generate process sequence for a part, and then match detail procedure design and select process equipment. A set of recursive formulas are found. Finally a complete process program is produced. The method is simple than that of the knowledge system, the artificial neural networks and variant approach computer aided process planning(VACAPP).展开更多
文摘To mutagenize two conserved CCCT and PTK motifs in the central domain of Chinese strain of potato Y potyvirus (PVY-C) helper component proteinase (HC-Pro), four mutants of HC-Pro gene were obtained by PCR and site-directed mutagenesis, and then were inserted into the constitutive expression vector pBin438. Leaves from tobacco (Nicotiana tabacum L. cv. K326) were transformed with these four plant expression plasmids by Agrobacterium-mediated transformation, respectively. Southern and Western blotting analyses showed that these four mutants were integrated into tobacco genomic DNA and could express the corresponding proteins in most of die transgenic plants. The challenge of transgenic plants with potato X potexvirus (PVX) revealed that the expression products of PVY-C HC-Pro mutants in transgenic plants greatly abolished functions of HC-Pro in enhancing the accumulation and pathogenicity of PVX, indicating that CCCT and PTK motifs of HC-Pro were required for PVX/PVY synergism. Meanwhile, the results demonstrated that PVY-C HC-Pro had a function in accelerating the long-distance movement of PVX in these transgenic plants for the first time.
基金Project (2011CB605801) supported by the National Basic Research Program of ChinaProject (2011M500127) supported by the China Postdoctoral Science Foundation+1 种基金Projects (50802115, 51102089) supported by the National Natural Science Foundation of ChinaProject supported by the Postdoctoral Fund of the Central South University, China
文摘Novel headstand pyrocarbon cones （HPCs） with hollow structure were developed on the surfaces of pyrocarbon layers of the carbon/carbon （C/C） composites at 650-750 °C by the electromagnetic-field-assisted chemical vapor deposition in the absence of catalysts. The fine microstructures of the HPCs were characterized by high-resolution transmission electron microscopy. The results show that the textural features of the HPCs directly transfer from turbostratic structure in roots to a well-ordered high texture in stems. And the degree of high texture ordering decreases gradually from the stem to the tail of the HPCs. The formation mechanism of the HPCs was inferred as the comprehensive effect of polarization induction on electromagnetic fields and particle-filler property under disruptive discharge.
文摘In this paper, the generative approach utilizes recursion to generate process sequence for a part, and then match detail procedure design and select process equipment. A set of recursive formulas are found. Finally a complete process program is produced. The method is simple than that of the knowledge system, the artificial neural networks and variant approach computer aided process planning(VACAPP).
