Cloning and Drought Resistance Analysis of Soybean GmHsps_p23-like Gene

Soybean(Glycine max(L.)Merr.)is an important cultivated crop,which requires much water during its growth,and drought seriously affects soybean yields.Studies have shown that the expression of small heat shock proteins can enhance drought resistance,cold resistance and salt resistance of plants.In this experiment,soybean GmHsps_p23-like gene was successfully cloned by RT-PCR,the protein encoded by the GmHsps_p23-like gene was subjected to bioinformatics analysis,and the pCAMBIA3301-GmHsps_p23-like overexpression vector and pCBSG015-GmHsps_p23-like gene editing vector were constructed.Agrobacterium-mediated method was used to transform soybeans to obtain positive plants.RT-PCR detection,rehydration experiment and drought resistance physiological and biochemical index detection were performed on the T2 generation positive transgenic soybean plants identified by PCR and Southern hybridization.The results showed that the overexpression vector plant GmHsps_p23-like gene expression increased.After rehydration,the transgenic overexpression plants returned to normal growth,and the damage to the plants was low.After drought stress,the SOD and POD activities and the PRO content of the transgenic overexpression plants increased,while the MDA content decreased.The reverse was true for soybean plants with genetically modified editing vectors.The drought resistance of the overexpressed soybeans under drought stress was higher than that of the control group,and had a stronger drought resistance.It showed that the expression of soybean GmHsps_p23-like gene can improve the drought resistance of soybean.The cloning and functional verification of soybean GmHsps_p23-like gene had not been reported yet.This is the first time that PCR technology has been used to amplify the soybean GmHsps_p23-like gene and construct an expression vector for this gene.This research has laid the foundation for transgenic technology to improve plant drought resistance and cultivate new drought-resistant transgenic soybean varieties.

3D Physical Simulation of Water Flooding Characteristics of Buried Hill Reservoir with Different Fracture Systems

In order to understand the water-flooding characteristics of different fracture systems in metamorphic rock buried hill reservoirs and the mechanism of improving water-flooding development effect, a three-dimensional physical model of fractured reservoirs is established according to the similarity criterion based on the prototype of metamorphic buried hill reservoirs in JZ Oilfield in Bohai Bay Basin. Combined with the fractured reservoir characteristics of JZ Oilfield, the water displacement characteristics of the top-bottom staggered injection-production well pattern in different fracture network mode and different fracture development degree of buried hill reservoir are studied. The experimental results show that: 1) the more serious the fracture system irregularity is, the shorter the water-free oil production period is and the lower the water-free oil recovery is. After water breakthrough of production wells, the water cut rises faster, and the effect of water flooding development is worse;2) under the condition of non-uniform fracture development, the development effect of the bottom fracture undeveloped is better than that of the middle fracture undeveloped. Water injection wells are deployed in areas with relatively few fractures, while oil wells are deployed in fractured areas with higher oil recovery and better development effect.

Water bridges are essential to neonicotinoids: Insights from synthesis,bioassay and molecular modelling studies

Water-bridged H-bonds have been observed in many cases of ligand-receptor recognitions. To explore the roles of water bridges in the binding of neonicotinoids with receptors, twenty-four neonicotinoid compounds with nine fragments, including 1 H-1,2,3-triazole, CN, COOMe, CONHNH_2, CONHMe, NO_2,NH_2, NHCOMe and NHCSNH_2 were synthesized and evaluated, of which, compounds with cyano group showed the best activities against Aphis craccivora. Accordingly, the cyano group is the optimal fragment mimicking the water bridge. Two cyano-substituted cis-nitromethylene compounds display good insecticidal activities, whereas the LC_(50) values are lower than those of their corresponding prototypes.Docking study showed that the cyano group acts only as H-bond acceptor, while the water bridge can act as both donor and acceptor. It revealed that the water bridge might be stable in the active site and was not suitable to be replaced by other groups. The findings illustrated that the water bridge is necessary for high insecticidal activities of neonicotinoids, which should be also helpful in better understanding the binding mode of neonicotinoids.

Improved multi-orientation dispersion of short carbon fibers in aluminum matrix composites prepared with square crucible by mechanical stirring

In order to improve the strength of short carbon fibers reinforced aluminum matrix(Csf/Al)composite,the dispersion of short carbon fibers with multi-orientation was controlled with a square crucible by mechanical stirring.The three-dimensional flow field models of liquid aluminum melt in the square/round crucibles were established and calculated,and the results were compared.The calculated results show that turbulent flow could be induced both in the square and round crucible,while the non-axisymmetric structure of the square crucible results in higher turbulent kinetic energy in the melt.Therefore,the uniformity and multi-orientation dispersion of the short fibers can be improved by the intensive turbulent flow in the square crucible,which will be increased by increasing the rotational velocity.The distribution of the short carbon fibers in the aluminum matrix prepared under different rotation velocities in square crucible was experimentally investigated.With the increase of stirring velocity,the multi-orientation dispersion of the short fibers in the composites increased gradually.The experimental results are consistent with the calculation results.The tensile testing results show that the strength of the Csf/Al composite can reach 172 MPa when the rotational velocity is 1000 rpm,and it is 48.3%higher than that prepared by the round crucible under the same conditions,which results from the improved multi-orientation dispersion of short carbon fibers in aluminum matrix.