We examined the changes of chemical composition and protein conformation in Arabidopsis leaves by Fourier transform-infrared (FT-IR) spectrometry Arabidopsis under 50 mmol/L NaCl salt and -0.5 mPa polyethylene glycols...We examined the changes of chemical composition and protein conformation in Arabidopsis leaves by Fourier transform-infrared (FT-IR) spectrometry Arabidopsis under 50 mmol/L NaCl salt and -0.5 mPa polyethylene glycols 8000 (PEG 8000) drought stress during the early stages of growth.We primarily analyzed the absorption band areas in the 1,745 cm-1 (ester),1,600-1,700 cm-1 (amide I),and 1,100 cm-1 (carbohydrate) changes under salt stress and drought stress within 24 hours.The results showed that ester content declined at the beginning and then increased steadily during 24 hours of drought stress.But under salt stress,it de-clined steadily,and it was about 40 percent of the control after 24 hours.The protein synthesis increased by 25 percent after one hour of salt stress and then reached about 85 percent of the control after 24 hours.Under drought stress,the protein synthesis de-creased and reached aminimal level at the 4-hr time point;it then recovered to the control level at the 24-hr point.The patterns of the accumulation of carbohydrates in the 1,100 cm-1 band areas resembled that of amide I band changes under drought stress and salt stress.Analyzing the ratio A1,627cm-1/A1,658cm-1 under drought stress revealed that the leaves’ entire protein structure maintained a higher-level ordered form than did those under salt stress.Thus our results indicate the existence of different strategies of the Arabidopsis adaptation to salt stress and drought stress.展开更多
A Ce^（3＋）tion-doped α-Na YF_4 single crystal of high quality is grown successfully by an improved flux Bridgman method under the conditions of taking the chemical raw composition of Na F：KF：YF_3：CeF_3 in the mo...A Ce^（3＋）tion-doped α-Na YF_4 single crystal of high quality is grown successfully by an improved flux Bridgman method under the conditions of taking the chemical raw composition of Na F：KF：YF_3：CeF_3 in the molar ratio of30∶18∶48∶4, where the KF is shown to be an effective assistant flux. The x ray diffraction, absorption spectra,excitation spectra, and emission spectra of the Ce^（3＋）t-doped α-Na YF_4 single crystal are measured to investigate the phase and optical properties of the single crystals. The absorption spectrum of the Ce^（3＋）t：α-Na YF_4 shows a strong band that peaks at the wavelength of 300 nm. The emission spectrum of the Ce^（3＋）t：α-Na YF_4 emits an intense ultraviolet（UV） band at the wavelength of 332 nm under the excitation of 300 nm light. Two separated luminous bands of 330 and 350 nm, which correspond to the transitions 5d → 2F25∕2and 5d → F7∕2, can be obtained by Gauss fitting. The strong emission intensity at the UV band and the excellent optical transmission in the range of UV wavelengths indicate that Ce^（3＋）t：α-Na YF_4 single crystals can be considered as a promising material for UV lasers.展开更多
基金supported by the National Science Foundation of China (30770343,40825001)the One Hundred Talent Project (O827751001) of Chinese Academy of Sciences
文摘We examined the changes of chemical composition and protein conformation in Arabidopsis leaves by Fourier transform-infrared (FT-IR) spectrometry Arabidopsis under 50 mmol/L NaCl salt and -0.5 mPa polyethylene glycols 8000 (PEG 8000) drought stress during the early stages of growth.We primarily analyzed the absorption band areas in the 1,745 cm-1 (ester),1,600-1,700 cm-1 (amide I),and 1,100 cm-1 (carbohydrate) changes under salt stress and drought stress within 24 hours.The results showed that ester content declined at the beginning and then increased steadily during 24 hours of drought stress.But under salt stress,it de-clined steadily,and it was about 40 percent of the control after 24 hours.The protein synthesis increased by 25 percent after one hour of salt stress and then reached about 85 percent of the control after 24 hours.Under drought stress,the protein synthesis de-creased and reached aminimal level at the 4-hr time point;it then recovered to the control level at the 24-hr point.The patterns of the accumulation of carbohydrates in the 1,100 cm-1 band areas resembled that of amide I band changes under drought stress and salt stress.Analyzing the ratio A1,627cm-1/A1,658cm-1 under drought stress revealed that the leaves’ entire protein structure maintained a higher-level ordered form than did those under salt stress.Thus our results indicate the existence of different strategies of the Arabidopsis adaptation to salt stress and drought stress.
基金supported by the National Natural Science Foundation of China(Nos.51472125 and51272109)the K.C.Wong Magna Fund of Ningbo University
文摘A Ce^（3＋）tion-doped α-Na YF_4 single crystal of high quality is grown successfully by an improved flux Bridgman method under the conditions of taking the chemical raw composition of Na F：KF：YF_3：CeF_3 in the molar ratio of30∶18∶48∶4, where the KF is shown to be an effective assistant flux. The x ray diffraction, absorption spectra,excitation spectra, and emission spectra of the Ce^（3＋）t-doped α-Na YF_4 single crystal are measured to investigate the phase and optical properties of the single crystals. The absorption spectrum of the Ce^（3＋）t：α-Na YF_4 shows a strong band that peaks at the wavelength of 300 nm. The emission spectrum of the Ce^（3＋）t：α-Na YF_4 emits an intense ultraviolet（UV） band at the wavelength of 332 nm under the excitation of 300 nm light. Two separated luminous bands of 330 and 350 nm, which correspond to the transitions 5d → 2F25∕2and 5d → F7∕2, can be obtained by Gauss fitting. The strong emission intensity at the UV band and the excellent optical transmission in the range of UV wavelengths indicate that Ce^（3＋）t：α-Na YF_4 single crystals can be considered as a promising material for UV lasers.
