In order to further understand the effects of drought stress on hydraulic characteristics and the relationship between hydraulic conductivity and aquaporins or water channels of root systems of three wolfberry cultiva...In order to further understand the effects of drought stress on hydraulic characteristics and the relationship between hydraulic conductivity and aquaporins or water channels of root systems of three wolfberry cultivars(Lycium chinense Mill.),hydraulic conductivity of 2-yearold pot-grown seedlings was measured under drought stress,rewatering,and treatment with exogenous mercuric chloride andβ-mercaptoethanol.Under moderate and severe drought stress levels,the most significant decrease of hydraulic conductivity was 37.3%and 24.0%,respectively,in the‘Ningqi 5’cultivar compared with the nonstressed control.After rewatering,the rate of recovery in specific conductivity was most rapid in the‘Mengqi 1’cultivar,at 0.058 and 0.072 kg MPa^-1 m^-2 s^-1 h^-1 under moderate and severe drought stress levels,respectively.The‘Mengqi 1’cultivar had the highest recovery degree of hydraulic conductivity under two concentrations ofβ-ME(500 or 1000 lmol L^-1),reaching 82.4%and 88.5%,respectively,of the initial conductivity.The adaptive capacity of hydraulic conductivity in the‘Ningqi 5’cultivar was weaker than in the‘Ningqi 1’and‘Mengqi 1’cultivars under drought stress.The recovery capacity of hydraulic conductivity in‘Mengqi 1’cultivar was stronger than the‘Ningqi 1’and‘Ningqi 5’cultivars after rewatering.Aquaporins of the‘Ningqi 1’cultivar root systems had the highest binding affinity with mercuric chloride,which was the most likely cause in the decrease in hydraulic conductivity,whereas aquaporins of‘Mengqi 1’root systems had the weakest binding affinity.The inhibitory effect of mercuric chloride was readily eliminated byβ-mercaptoethanol in the‘Mengqi 1’cultivar.The hydraulic characteristics of this cultivar were more sensitive to drought,mercuric chloride andβ-mercaptoethanol than the other cultivars.展开更多
Quantum dots(QDs)luminescent films are extensively applied to optoelectronics and optical devices.However,QDs aggregation results in the quenching of their fluorescence property which limits their practical applicatio...Quantum dots(QDs)luminescent films are extensively applied to optoelectronics and optical devices.However,QDs aggregation results in the quenching of their fluorescence property which limits their practical applications to a greater extent.In order to resolve this issue,3-mercaptopropionic acid(3-MPA)functionalized Cadmium Tellurium(CdTe)QDs were stabilized by silk fibroin(SB)and coassembled with layered doubled hydroxide(LDH)to form(QDs@SF/LDH)_(n)ultrathin films(UTFs)via the layer-by-layer(LBL)technique.UV-Vis absorption and fluorescence spectroscopy showed a stepwise and normal growth of the films upon increasing the number of deposition cycles.XRD and AFM studies confirmed the formation of a periodic layered structure and regular surface morphology of the thin films.As compared to(CdTe QDs/LDH)_(n)UTFs,the(CdTe QDs@SF/LDH)_(n)UTFs displayed fluorescence enhancement and longer fluorescent lifetime,both in solid states and aqueous solutions.Furthermore compared with the solution state,the fluorescence enhancement of SF-RC and SF-β are,respectively,7 times and 17 times in the(CdTe QDs@SF/LDH)_(n)UTFs,indicating that the LDH nanosheets favor the fluorescence enhancement effect on the CdTe QDs@SF.The fabricated materials displayed fluorescence response to a biological molecule such as immune globulin,lgG.Thus,the(CdTe QDs@SF/LDH)_(n)UTFs has a potential to be used as biosensor.展开更多
基金the National Natural Science Foundation of China(Grant No.31560380)Chief Expert of Modern Agricultural Traditional Chinese Medicine Industry System in Gansu Province(GARS-ZYC-1)the Open Project of Qinghai Key Laboratory of Qinghai-Tibet Plateau Biological Resources(Grant No.2017-ZJ-Y10)。
文摘In order to further understand the effects of drought stress on hydraulic characteristics and the relationship between hydraulic conductivity and aquaporins or water channels of root systems of three wolfberry cultivars(Lycium chinense Mill.),hydraulic conductivity of 2-yearold pot-grown seedlings was measured under drought stress,rewatering,and treatment with exogenous mercuric chloride andβ-mercaptoethanol.Under moderate and severe drought stress levels,the most significant decrease of hydraulic conductivity was 37.3%and 24.0%,respectively,in the‘Ningqi 5’cultivar compared with the nonstressed control.After rewatering,the rate of recovery in specific conductivity was most rapid in the‘Mengqi 1’cultivar,at 0.058 and 0.072 kg MPa^-1 m^-2 s^-1 h^-1 under moderate and severe drought stress levels,respectively.The‘Mengqi 1’cultivar had the highest recovery degree of hydraulic conductivity under two concentrations ofβ-ME(500 or 1000 lmol L^-1),reaching 82.4%and 88.5%,respectively,of the initial conductivity.The adaptive capacity of hydraulic conductivity in the‘Ningqi 5’cultivar was weaker than in the‘Ningqi 1’and‘Mengqi 1’cultivars under drought stress.The recovery capacity of hydraulic conductivity in‘Mengqi 1’cultivar was stronger than the‘Ningqi 1’and‘Ningqi 5’cultivars after rewatering.Aquaporins of the‘Ningqi 1’cultivar root systems had the highest binding affinity with mercuric chloride,which was the most likely cause in the decrease in hydraulic conductivity,whereas aquaporins of‘Mengqi 1’root systems had the weakest binding affinity.The inhibitory effect of mercuric chloride was readily eliminated byβ-mercaptoethanol in the‘Mengqi 1’cultivar.The hydraulic characteristics of this cultivar were more sensitive to drought,mercuric chloride andβ-mercaptoethanol than the other cultivars.
基金This work was supported by the 973 Program(Grant2014CB932101)the National Natural Science Foundation of China,111 Project(Grant no.B07004)Innovation Research Team in University and Central University Research Funds of China(buctrc201527).
文摘Quantum dots(QDs)luminescent films are extensively applied to optoelectronics and optical devices.However,QDs aggregation results in the quenching of their fluorescence property which limits their practical applications to a greater extent.In order to resolve this issue,3-mercaptopropionic acid(3-MPA)functionalized Cadmium Tellurium(CdTe)QDs were stabilized by silk fibroin(SB)and coassembled with layered doubled hydroxide(LDH)to form(QDs@SF/LDH)_(n)ultrathin films(UTFs)via the layer-by-layer(LBL)technique.UV-Vis absorption and fluorescence spectroscopy showed a stepwise and normal growth of the films upon increasing the number of deposition cycles.XRD and AFM studies confirmed the formation of a periodic layered structure and regular surface morphology of the thin films.As compared to(CdTe QDs/LDH)_(n)UTFs,the(CdTe QDs@SF/LDH)_(n)UTFs displayed fluorescence enhancement and longer fluorescent lifetime,both in solid states and aqueous solutions.Furthermore compared with the solution state,the fluorescence enhancement of SF-RC and SF-β are,respectively,7 times and 17 times in the(CdTe QDs@SF/LDH)_(n)UTFs,indicating that the LDH nanosheets favor the fluorescence enhancement effect on the CdTe QDs@SF.The fabricated materials displayed fluorescence response to a biological molecule such as immune globulin,lgG.Thus,the(CdTe QDs@SF/LDH)_(n)UTFs has a potential to be used as biosensor.
