Methods for the localization of plant calmodulin by immuno-gold and immuno-peroxidase electron microscopy have been developed. In both corn root-cap cells and meristematic cells, calmodulin was found to be localized i...Methods for the localization of plant calmodulin by immuno-gold and immuno-peroxidase electron microscopy have been developed. In both corn root-cap cells and meristematic cells, calmodulin was found to be localized in the nucleus, cytoplasm, mitochondria as well as in the cell wall. In the meristematic cells, calmodulin was distinctly localized on the plasma membrane, cytoplasmic face of rough endoplasmic reticulum and polyribosomes. Characteristically, calmodulin was present in the amyloplasts of root-cap cells. The widespread distribution of calmodulin may reflect its pleiotropic functions in plant cellular activities.展开更多
The effect of lanthanum ion on membrane permeability of corn root segment is studied.Results shows that treatment of the root segments with LaCl_3·7H_2O can decrease the ion leakage of the root tissue.The leakage...The effect of lanthanum ion on membrane permeability of corn root segment is studied.Results shows that treatment of the root segments with LaCl_3·7H_2O can decrease the ion leakage of the root tissue.The leakage decreases hy increasing the concentration of lanthanum,and the concentration has no further dependence on ion leakages above 25 μmol/L.After treating the root tissue for one hour with lanthanum ion,the amount of leak- age has linear dependence on time within the first 2 h and after two hours the leakage increases.The ion leakage of the tissue dependes on the time of lanthanum treatment.When the duration of treatment is prolonged,the leakage decreases rapidly and the leakage reaches a minimum at 30 minutes.Other rare earth elements can also decrease ion leakage.There is no significant difference in the ion leakage among these elements.展开更多
Seeking high performance adsorbents for highly efficient treatment of wastewater containing organic dyes has become increasingly imperative worldwide.Herein,with a specific surface area(SSA)of 2,745.4 m^(2)·g^(−1...Seeking high performance adsorbents for highly efficient treatment of wastewater containing organic dyes has become increasingly imperative worldwide.Herein,with a specific surface area(SSA)of 2,745.4 m^(2)·g^(−1),trace N-doped porous biochar nanospheres(NPBs)are derived for the first time from affluent waste corn roots,via a hydrothermal conversion followed by a mild calcined activation by K2CO3(KC)in the presence of low virulent melamine.Melamine acts as N source and synergistic activator for significant promotion in SSA,pore volume,and surface defects.The obtained NPBs(CHC-0.5N-4KC-900)are confirmed as superior adsorbents for removal of organic dyes rhodamine B(RhB,qm=1,630.7 mg·g^(−1))and Congo red(CR,qm=1,766.2 mg·g^(−1))as well as their mixtures,within not only a low(<50 mg·L^(−1))but also a high(>50,esp.250–1500 mg·L^(−1))concentration range.The values for qm are far beyond commercially activated carbon(AC)as well as most reported biomass derived carbons,undoubtedly revealing the NPBs as great promising candidate adsorbents for disposal of real industrial wastewater.In addition,the adsorption of RhB is fitted by Langmuir,Freundlich,Temkin,and Dubinin–Radushkevich isotherm models.The kinetic analysis indicates that the adsorption before equilibrium conforms to the pseudo-second-order model,and the hydrogen bonding,electrostatic attraction,and esp.π–πinteraction have contributed to the superior adsorption performance of the NPBs.展开更多
A study was conducted at Akron, CO, USA, on a Weld silt loam in 2004 to quantify the effects of water deficit stress on corn (Zea mays, L.) root and shoot biomass. Corn plants were grown under a range of soil bulk den...A study was conducted at Akron, CO, USA, on a Weld silt loam in 2004 to quantify the effects of water deficit stress on corn (Zea mays, L.) root and shoot biomass. Corn plants were grown under a range of soil bulk density and water conditions caused by previous tillage, crop rotation, and irrigation management. Water deficit stress (Dstress) was quantified by the number of days when the water content in the surface 0.3 m deviated from the water content range determined by the Least Limiting Water Range (LLWR). Root and shoot samples were collected at the V6, V12, and R1 growth stages. There was no significant correlation between Dstress and shoot or root biomass at the V6 growth stage. At the V12 and R1 growth stages, there were negative, linear correlations among Dstress and both root biomass and shoot biomass. The proportional decrease of shoot biomass was greater than the proportional decrease in root biomass, leading to an increase in the root:shoot ratio as water deficit stress increased at all growth stages. Determining restrictive soil conditions using the LLWR may be useful for evaluating improvement or degradation of the soil physical environment caused by soil management.展开更多
Plant growth-promoting rhizobacteria (PGPR) colonize plant roots and promote plant growth by producing and secreting various chemical regulators in the rhizosphere. With the recent interest in sustainable agriculture,...Plant growth-promoting rhizobacteria (PGPR) colonize plant roots and promote plant growth by producing and secreting various chemical regulators in the rhizosphere. With the recent interest in sustainable agriculture, an increasing number of researchers are investigating ways to improve the efficiency of PGPR use to reduce chemical fertilizer inputs needed for crop production. Accordingly, greenhouse studies were conducted to evaluate the impact of PGPR inoculants on biomass production and nitrogen (N) content of corn (Zea mays L.) under different N levels. Treatments included three PGPR inoculants (two mixtures of PGPR strains and one control without PGPR) and five N application levels (0%, 25%, 50%, 75%, and 100% of the recommended N rate of 135 kg N ha−1). Results showed that inoculation of PGPR significantly increased plant height, stem diameter, leaf area, and root morphology of corn compared to no PGPR application under the same N levels at the V6 growth stage, but few differences were observed at the V4 stage. PGPR with 50% of the full N rate produced corn biomass and N concentrations equivalent to or greater than that of the full N rate without inoculants at the VT stage. In conclusion, mixtures of PGPR can potentially reduce inorganic N fertilization without affecting corn plant growth parameters. Future research is needed under field conditions to determine if these PGPR inoculants can be integrated as a bio-fertilizer in crop production nutrient management strategies.展开更多
间作是世界古老的农田种植模式,合理的间作可增加叶片的光合效率,作物间竞争与合作,促进植株生长发育。本研究设置3种种植模式:玉米‖棉花、单作玉米和单作棉花,分别对植株的农艺性状、叶片叶绿素相对含量、产量构成因素以及根系分布特...间作是世界古老的农田种植模式,合理的间作可增加叶片的光合效率,作物间竞争与合作,促进植株生长发育。本研究设置3种种植模式:玉米‖棉花、单作玉米和单作棉花,分别对植株的农艺性状、叶片叶绿素相对含量、产量构成因素以及根系分布特征对作物生长发育与产量形成等方面进行了探讨和分析。最后结果说明,玉米间作棉花种植模式可以使玉米株高提高5.41%~46.29%,SPAD值变化幅度为-0.5%~26%。0~20 cm、20~40 cm RLD值分别增加51.37%~68.30%、40.39%~88.14%;间作使棉花株高降低9.51%~19.88%,SPAD值降低了1.71%~10.17%,0~20 cm、20~40 cm RLD值分别增加29.11%~40.89%、49.08%~96.32%。玉米间作棉花的土地当量比LER=1.2802>1,增产率为28.02%。并得到结论:玉米间作棉花种植模式下能有效提升大田的作物产量,但具体主要影响需进一步深入研究。展开更多
文摘Methods for the localization of plant calmodulin by immuno-gold and immuno-peroxidase electron microscopy have been developed. In both corn root-cap cells and meristematic cells, calmodulin was found to be localized in the nucleus, cytoplasm, mitochondria as well as in the cell wall. In the meristematic cells, calmodulin was distinctly localized on the plasma membrane, cytoplasmic face of rough endoplasmic reticulum and polyribosomes. Characteristically, calmodulin was present in the amyloplasts of root-cap cells. The widespread distribution of calmodulin may reflect its pleiotropic functions in plant cellular activities.
文摘The effect of lanthanum ion on membrane permeability of corn root segment is studied.Results shows that treatment of the root segments with LaCl_3·7H_2O can decrease the ion leakage of the root tissue.The leakage decreases hy increasing the concentration of lanthanum,and the concentration has no further dependence on ion leakages above 25 μmol/L.After treating the root tissue for one hour with lanthanum ion,the amount of leak- age has linear dependence on time within the first 2 h and after two hours the leakage increases.The ion leakage of the tissue dependes on the time of lanthanum treatment.When the duration of treatment is prolonged,the leakage decreases rapidly and the leakage reaches a minimum at 30 minutes.Other rare earth elements can also decrease ion leakage.There is no significant difference in the ion leakage among these elements.
基金supported by the State Key Laboratory of Chemical Engineering,China(No.SKL-ChE-21A02)State Key Laboratory of Organic-Inorganic Composites,China(No.oic-202101009)+2 种基金the Natural Science Foundation of Shandong Province,China(No.ZR2022MB075)the National Natural Science Foundation of China(No.22075304)Beijing Natural Science Foundation,China(No.3222050).
文摘Seeking high performance adsorbents for highly efficient treatment of wastewater containing organic dyes has become increasingly imperative worldwide.Herein,with a specific surface area(SSA)of 2,745.4 m^(2)·g^(−1),trace N-doped porous biochar nanospheres(NPBs)are derived for the first time from affluent waste corn roots,via a hydrothermal conversion followed by a mild calcined activation by K2CO3(KC)in the presence of low virulent melamine.Melamine acts as N source and synergistic activator for significant promotion in SSA,pore volume,and surface defects.The obtained NPBs(CHC-0.5N-4KC-900)are confirmed as superior adsorbents for removal of organic dyes rhodamine B(RhB,qm=1,630.7 mg·g^(−1))and Congo red(CR,qm=1,766.2 mg·g^(−1))as well as their mixtures,within not only a low(<50 mg·L^(−1))but also a high(>50,esp.250–1500 mg·L^(−1))concentration range.The values for qm are far beyond commercially activated carbon(AC)as well as most reported biomass derived carbons,undoubtedly revealing the NPBs as great promising candidate adsorbents for disposal of real industrial wastewater.In addition,the adsorption of RhB is fitted by Langmuir,Freundlich,Temkin,and Dubinin–Radushkevich isotherm models.The kinetic analysis indicates that the adsorption before equilibrium conforms to the pseudo-second-order model,and the hydrogen bonding,electrostatic attraction,and esp.π–πinteraction have contributed to the superior adsorption performance of the NPBs.
文摘A study was conducted at Akron, CO, USA, on a Weld silt loam in 2004 to quantify the effects of water deficit stress on corn (Zea mays, L.) root and shoot biomass. Corn plants were grown under a range of soil bulk density and water conditions caused by previous tillage, crop rotation, and irrigation management. Water deficit stress (Dstress) was quantified by the number of days when the water content in the surface 0.3 m deviated from the water content range determined by the Least Limiting Water Range (LLWR). Root and shoot samples were collected at the V6, V12, and R1 growth stages. There was no significant correlation between Dstress and shoot or root biomass at the V6 growth stage. At the V12 and R1 growth stages, there were negative, linear correlations among Dstress and both root biomass and shoot biomass. The proportional decrease of shoot biomass was greater than the proportional decrease in root biomass, leading to an increase in the root:shoot ratio as water deficit stress increased at all growth stages. Determining restrictive soil conditions using the LLWR may be useful for evaluating improvement or degradation of the soil physical environment caused by soil management.
文摘Plant growth-promoting rhizobacteria (PGPR) colonize plant roots and promote plant growth by producing and secreting various chemical regulators in the rhizosphere. With the recent interest in sustainable agriculture, an increasing number of researchers are investigating ways to improve the efficiency of PGPR use to reduce chemical fertilizer inputs needed for crop production. Accordingly, greenhouse studies were conducted to evaluate the impact of PGPR inoculants on biomass production and nitrogen (N) content of corn (Zea mays L.) under different N levels. Treatments included three PGPR inoculants (two mixtures of PGPR strains and one control without PGPR) and five N application levels (0%, 25%, 50%, 75%, and 100% of the recommended N rate of 135 kg N ha−1). Results showed that inoculation of PGPR significantly increased plant height, stem diameter, leaf area, and root morphology of corn compared to no PGPR application under the same N levels at the V6 growth stage, but few differences were observed at the V4 stage. PGPR with 50% of the full N rate produced corn biomass and N concentrations equivalent to or greater than that of the full N rate without inoculants at the VT stage. In conclusion, mixtures of PGPR can potentially reduce inorganic N fertilization without affecting corn plant growth parameters. Future research is needed under field conditions to determine if these PGPR inoculants can be integrated as a bio-fertilizer in crop production nutrient management strategies.
文摘间作是世界古老的农田种植模式,合理的间作可增加叶片的光合效率,作物间竞争与合作,促进植株生长发育。本研究设置3种种植模式:玉米‖棉花、单作玉米和单作棉花,分别对植株的农艺性状、叶片叶绿素相对含量、产量构成因素以及根系分布特征对作物生长发育与产量形成等方面进行了探讨和分析。最后结果说明,玉米间作棉花种植模式可以使玉米株高提高5.41%~46.29%,SPAD值变化幅度为-0.5%~26%。0~20 cm、20~40 cm RLD值分别增加51.37%~68.30%、40.39%~88.14%;间作使棉花株高降低9.51%~19.88%,SPAD值降低了1.71%~10.17%,0~20 cm、20~40 cm RLD值分别增加29.11%~40.89%、49.08%~96.32%。玉米间作棉花的土地当量比LER=1.2802>1,增产率为28.02%。并得到结论:玉米间作棉花种植模式下能有效提升大田的作物产量,但具体主要影响需进一步深入研究。
