Construction and functional analysis of nattokinase-producing cucumber obtained by the CRISPR-Cas9 system

Nattokinase (NK) is effective in the prevention and treatment of cardiovascular disease. Cucumber is rich in nutrients with low sugar content and is safe for consumption. The aim of this study was to construct a therapeutic cucumber that can express NK, which can prevent and alleviate cardiovascular diseases by consumption. Because the Bitter fruit ( Bt ) gene contributes to bitter taste but has no obvious effect on the growth and development of cucumber, so the NK-producing cucumber was constructed by replacing the Bt gene with NK by using CRISPR/Cas9. The pZHY988-Cas9-sgRNA and pX6-LHA-U6-NK-T-RHA vectors were constructed and transformed into Agrobacterium tumefaciens EHA105, which was transformed into cucumber by floral dip method. The crude extract of NK-producing cucumber had significant thrombolytic activity in vitro . In addition, treatment with the crude extract significantly delayed thrombus tail appearance, and the thrombin time of mice was much longer than that of normal mice. The degrees of coagulation and blood viscosity as well as hemorheological properties improved significantly after crude extract treatment. These findings show that NK-producing cucumber can effectively alleviate thrombosis and improve blood biochemical parameters, providing a new direction for diet therapy against cardiovascular diseases

High pressure synthesis of a new superconductor Sr2CuO2+xCl2-y induced by apical oxygen doping

Using the apical oxygen doping mechanism, i.e. a partial substitution of divalence O for the monovalence Cl, a p-type oxychloride cuprate superconductor, Sr2CuO2+xCl2-y, was synthesized at high pressure high temperature. The x-ray diffraction refinement suggests the superconductor crystallizes into a 0201 structure with space group I4/mmm and lattice parameters being a=3.92A, c=15.6 A. The magnetic susceptibility as well as resistance measurements indicated that the bulk superconductivity with transition temperature 30K was achieved in the sample.Comment: accepted by physica

Seasonal dynamics in cambial activity and the formation of xylem and phloem in the branches of Cinnamomum camphora

The cambial activity and periodicity of secondary xylem and phloem formation have been less studied in tropical tree species than in temperate ones. Cambium activity is the only source of timber production. Studies on its activity and xylem formation can provide helpful data for dendrochronology and possible factors that control tree growth, the yield and quality of wood. Cinnamomum camphora is an important fast-growing tree for furniture and sculpture wood in South China. Its dynamics of cambial activity was not reported. During the growth season in 2011, five trees of Cinnamomum camphora plantation were monitored on the campus of Huazhong Agricultural University in central china (located on 113°41’ to 115°05’ E and 29°58’ to 31°22’ N). Sampling time was from 13, February 2011 to 13, February 2012. Some small stems of 15–20 cm length were selected to sample in the middle of 2–3 years old health branches in the central crown of these trees. The observational study found that the cambium of camphor trees was active from March to October and dormant from November to February. Onset of cambial cell division was observed in early March, one week after sprouting of new buds. The morphology of the cells and number of cell layers in the cambium zone varied throughout the year. In early March, cambium reactivated with the rising of temperature, the cell wall was relative thick. The number of cell layers increased from 2–3 in middle Feb. to 3–5. In June, the number of cell layers in cambium reached the maximum of 5–7 in a radial direction. In mid March, phloem cells began to differentiate, followed by xylem three weeks later. The number of cell layers in immature phloem and xylem increased dramatically before mid June and the increment of cell layers in xylem was almost fifth times of phloem in the differentiating process. The phloem cells mainly stopped dividing new cells in end of October, but xylem cells were still in the activity a week later. The annual activities of cambium was in accordance with the air mean temperature change in 2011–2012. The results showed that the cambial activity and formation of xylem and phloem were related to the environmental factors, especially the temperature