Ammopiptanthus nanus is an endangered evergreen shrub endemic to the deserts of central Asia and plays an important role in delaying further desertification. We examined allozyme variation and AFLP diversity in A. nan...Ammopiptanthus nanus is an endangered evergreen shrub endemic to the deserts of central Asia and plays an important role in delaying further desertification. We examined allozyme variation and AFLP diversity in A. nanus populations and investigated the mating system of this species using progeny arrays assayed for polymorphic allozyme loci. Mating system analysis in the Keyi＇eryongke＇er population showed low levels of outcrossing, and strong inbreeding depression. Low levels of genetic variation were detected at both population （allozyme, Pp=14.0%, A=l.14, He=0.031; AFLP, Pp=14.5%, Shannon＇s information index I=0.063） and species （allozyme, Pp=21.1%, A=1.21, He=0.040; AFLP, Pp=20.9%, I=0.083） levels; while moderate genetic differentiation existed among populations, as indicated by allozymes （Gsa-=0.081） and AFLP （GST=0.151-0.193）. Founder effect, bottlenecks in evolutionary history, the mixed mating system and co-ancestry may have influenced the level of genetic diversity in A. nanus. Markers of both types provide new insights for conservation management, indicating that the Biao＇ertuokuoyi and Keyi＇eryongke＇er populations should be given priority for in situ conservation and regarded as seed sources for ex situ conservation.展开更多
The conventional protein chromatography technique was adopted to purify the antifreeze proteins (AFPs) from the leaves of Ammopiptanthus mongolicus (Maxim.) Cheng f. Two bands on native PAGE gel showed thermal hys...The conventional protein chromatography technique was adopted to purify the antifreeze proteins (AFPs) from the leaves of Ammopiptanthus mongolicus (Maxim.) Cheng f. Two bands on native PAGE gel showed thermal hysteresis activity, one was band B1, whose thermal hysteresis was 0.46 ℃ at 8 g/L, which showed two bands (67 kD, 21 kD) on SDS_PAGE gel; the other was B3, whose thermal hysteresis was 0.45 ℃ at 10 g/L, and it contained only a single protein (39.8 kD). Both B1 and B3 are not glycoproteins, because neither do they interact with Shiff_reagent, nor show ultraviolet characteristics of a typical glycoprotein.展开更多
Ammopiptanthus mongolicus (Maxim.) Cheng f. is one of the evergreen shrubs in the desert region of China. In midday its leaves bear photon flux density over 1 500 μmol·m -2 ·s -1 at natural habit...Ammopiptanthus mongolicus (Maxim.) Cheng f. is one of the evergreen shrubs in the desert region of China. In midday its leaves bear photon flux density over 1 500 μmol·m -2 ·s -1 at natural habitat. They show the obvious phenomenon of photoinhibition. For the study of the effects of drought stress on the major protective mechanism against strong light in A. mongolicus leaves, the diurnal variations of photosynthetic rate and chlorophyll fluorescence parameters were investigated under natural conditions with portable photosynthetic measurement system (CIRAS_1) and portable fluorometer (MFMS_2). The experimental results showed that, under normal and drought stress conditions,the net photosynthetic rate ( Pn ), the primary maximum photochemical efficiency of PSⅡ ( Fv/Fm ) and the quantum efficiency of noncyclic electron transport of PSⅡ ( Φ PSⅡ ) decreased obviously at noon (Figs.2,3A,4B). In comparison with plants under normal condition, under drought stress minimal chlorophyll fluorescence ( Fo ) decreased at first and then increased (Fig.3A), non_photochemical quenching ( NPQ ) quickly increased and sustained at a higher level (Fig.4B). This indicated that the major photoprotective mechanism of A. mongolicus leaves was the xanthophyll cycle_dependent thermal energy dissipation under normal condition, while under drought stress, the major photoprotective mechanism was both the xanthophyll cycle_dependent thermal energy dissipation and the reversible inactivation of PSⅡ reaction center.展开更多
Objective To study the effects and the mechanisms of extract from a leguminous plant （Ammopiptanthus mongolicus cheng f.） （JAl ） in northwest China on inducing apoptosis and inhibiting proliferation of HepG2 hepat...Objective To study the effects and the mechanisms of extract from a leguminous plant （Ammopiptanthus mongolicus cheng f.） （JAl ） in northwest China on inducing apoptosis and inhibiting proliferation of HepG2 hepatocarcinoma cell in vitro. Methods The HepG2 cell line was used as target cells. The effect of 3A 1 on HepG2 cell growth was detected by microculture tetrazolium assay （MTr）, flow cytometry assay, DNA agarose gel electrophoresis and transmission electronic microscopy. The expressive effect of the wt-p53 in HepG2 cells was analyzed with p53 protein test-reagent. Results JAl not only had significant anti-proliferative effects depending upon time and dosage, but also induced apoptosis of HepG2 cells. Apoptotic typical morphological changes were observed in JAl-treated HepG2 cells under transmission electronic microscope, ＂Sub-G 1＂ phase peak occurred in flow cytometry and DNA ＂ladder＂ was found in DNA agarose gel electrophoresis. The expression of the wt-p53 increased in vitro, and 3Al-treated HepG2 and the positive cell percentage of the wt-p53 protein also increased. Conclusions JAl could obviously induce apoptosis and inhibit proliferation of HepG2 cells in vitro, and these effects are closely related with the increase of wt-p53 expression. JAl can be used as a good source of medicinal plant for the treatment of hepatocarcinoma.展开更多
Cold acclimation is associated with many metabolic changes that lead to an increase of freezing tolerance. In order to investigate the biochemical process of cold acclimation in Ammopiptanthus mongolicus, seedlings we...Cold acclimation is associated with many metabolic changes that lead to an increase of freezing tolerance. In order to investigate the biochemical process of cold acclimation in Ammopiptanthus mongolicus, seedlings were acclimated at 2℃ under 16-h photoperiod （150 μmol·m^-2·s^-1 photosynthetically active radiation） for 14 d. Freezing tolerance in seedlings increased after 14 d of cold-hardening. Contents of protein, proline and solute carbohydrate in cotyledon increased after cold acclimation. Patterns of isozymes of superoxide dismutase （SOD）, peroxidase, catalase and polyphenol oxidase （PPO） were investigated. The activities of SOD, peroxidase and PPO in cold acclimated plants were increased during cold-hardening. We deduced that compatible solutes and antioxidant enzymes play important roles in development of freezing tolerance during cold acclimation in this evergreen woody plant.展开更多
Ammopiptanthus mongolicus is the only evergreen broadleaved shrub endemic species to the Alashan Desert, northwest sand area of China, and can survive at -30℃ or even lower temperature in winter. A modified solid-pha...Ammopiptanthus mongolicus is the only evergreen broadleaved shrub endemic species to the Alashan Desert, northwest sand area of China, and can survive at -30℃ or even lower temperature in winter. A modified solid-phase subtraction hybridization technique was developed to isolate and screen cDNAs, whose transcripts increased in cold-treated A. mongolicus seedlings. Sequence analysis of the screened clones indicated that 11 clones had coding regions, with four of them containing complete open reading frame. And nine of the 11 clones shared various degrees of homology with the genes found in the GenBank database and the other two were unidentified sequences. Sequence data further revealed that these accumulated transcripts encode three low molecular weight proteins, a late-embryogenesis protein and two cold acclimation responsive proteins; two photosynthesis-related proteins, photosystem I subunit II precursor (PsaD) and photosystem II oxygen-evolving complex 33kDa subunit (OEC33); a protease inhibitor; an adenosine triphosphatase and a 14-3-3 related protein. Analysis on the function of these proteins indicated that the low molecular weight proteins were associated with water holding ability of cytoplasm; photosynthesis-related proteins participated in the adjustments of photosynthetic apparatus to resist photoinhibition; 14-3-3 related protein could interact with adenosine triphosphatase to enhance ATPase activity and energy metabolism; and protease inhibitor involved in the prevention of unwanted cell death was caused by reactive oxygen species. We suggest that cold acclimation with low light intensity in A. mongolicus is a more complex interaction of low temperature, light, energy and signal than that assumed previously.展开更多
Ammopiptanthus mongolicus, the only freezing tolerant evergreen broad-leaved shrub, local species of the Alashan desert, northwest sand area of China, can survive -30℃ or even lower temperature in winter. In the pres...Ammopiptanthus mongolicus, the only freezing tolerant evergreen broad-leaved shrub, local species of the Alashan desert, northwest sand area of China, can survive -30℃ or even lower temperature in winter. In the present study, the secondary products phenolics in A. mongolicus cotyledons were determined to study the effects of phenolics on cold tolerance. Cytochemical localization of phenolics in cotyledon cells was observed by electron microscopy and the content of phenolic compounds was assayed by spectrophotometric measurement. The results showed that the freezing tolerance ofA. mongolicus seedlings increased after acclimation at 2℃ for 14 days, which accompanied the increase of the content of phenolic compounds in cotyledons. Cytochemical observation showed that phenolic deposits were mainly localized in vacuoles and in close proximity to tonoplast, and also in the cytoplasm. The amount and the size of phenolics droplets increased obviously in cytoplasm and vacuoles after cold acclimation, predominantly aggregated along membranes of vacuoles and tonoplast. No phenolic deposits were found in cell walls. As hydrogen- or elec- tron-donating agents, phenolics may protect plant cells against reactive oxygen species formed during chilling or freezing stress and improve the freezing tolerance of cold-acclimated A. mongolicus seedlings.展开更多
基金supported by the National Natural Science Foundation of China (Grant No.30370282)Educational Commission of Hubei Province of China (Q20082201)Talent Introduction Funds of Hubei Normal University (2007F13)
文摘Ammopiptanthus nanus is an endangered evergreen shrub endemic to the deserts of central Asia and plays an important role in delaying further desertification. We examined allozyme variation and AFLP diversity in A. nanus populations and investigated the mating system of this species using progeny arrays assayed for polymorphic allozyme loci. Mating system analysis in the Keyi＇eryongke＇er population showed low levels of outcrossing, and strong inbreeding depression. Low levels of genetic variation were detected at both population （allozyme, Pp=14.0%, A=l.14, He=0.031; AFLP, Pp=14.5%, Shannon＇s information index I=0.063） and species （allozyme, Pp=21.1%, A=1.21, He=0.040; AFLP, Pp=20.9%, I=0.083） levels; while moderate genetic differentiation existed among populations, as indicated by allozymes （Gsa-=0.081） and AFLP （GST=0.151-0.193）. Founder effect, bottlenecks in evolutionary history, the mixed mating system and co-ancestry may have influenced the level of genetic diversity in A. nanus. Markers of both types provide new insights for conservation management, indicating that the Biao＇ertuokuoyi and Keyi＇eryongke＇er populations should be given priority for in situ conservation and regarded as seed sources for ex situ conservation.
文摘The conventional protein chromatography technique was adopted to purify the antifreeze proteins (AFPs) from the leaves of Ammopiptanthus mongolicus (Maxim.) Cheng f. Two bands on native PAGE gel showed thermal hysteresis activity, one was band B1, whose thermal hysteresis was 0.46 ℃ at 8 g/L, which showed two bands (67 kD, 21 kD) on SDS_PAGE gel; the other was B3, whose thermal hysteresis was 0.45 ℃ at 10 g/L, and it contained only a single protein (39.8 kD). Both B1 and B3 are not glycoproteins, because neither do they interact with Shiff_reagent, nor show ultraviolet characteristics of a typical glycoprotein.
文摘Ammopiptanthus mongolicus (Maxim.) Cheng f. is one of the evergreen shrubs in the desert region of China. In midday its leaves bear photon flux density over 1 500 μmol·m -2 ·s -1 at natural habitat. They show the obvious phenomenon of photoinhibition. For the study of the effects of drought stress on the major protective mechanism against strong light in A. mongolicus leaves, the diurnal variations of photosynthetic rate and chlorophyll fluorescence parameters were investigated under natural conditions with portable photosynthetic measurement system (CIRAS_1) and portable fluorometer (MFMS_2). The experimental results showed that, under normal and drought stress conditions,the net photosynthetic rate ( Pn ), the primary maximum photochemical efficiency of PSⅡ ( Fv/Fm ) and the quantum efficiency of noncyclic electron transport of PSⅡ ( Φ PSⅡ ) decreased obviously at noon (Figs.2,3A,4B). In comparison with plants under normal condition, under drought stress minimal chlorophyll fluorescence ( Fo ) decreased at first and then increased (Fig.3A), non_photochemical quenching ( NPQ ) quickly increased and sustained at a higher level (Fig.4B). This indicated that the major photoprotective mechanism of A. mongolicus leaves was the xanthophyll cycle_dependent thermal energy dissipation under normal condition, while under drought stress, the major photoprotective mechanism was both the xanthophyll cycle_dependent thermal energy dissipation and the reversible inactivation of PSⅡ reaction center.
基金This research was supported by the National Key Technologies R&D Program of China (No. 2001BA901A33)
文摘Objective To study the effects and the mechanisms of extract from a leguminous plant （Ammopiptanthus mongolicus cheng f.） （JAl ） in northwest China on inducing apoptosis and inhibiting proliferation of HepG2 hepatocarcinoma cell in vitro. Methods The HepG2 cell line was used as target cells. The effect of 3A 1 on HepG2 cell growth was detected by microculture tetrazolium assay （MTr）, flow cytometry assay, DNA agarose gel electrophoresis and transmission electronic microscopy. The expressive effect of the wt-p53 in HepG2 cells was analyzed with p53 protein test-reagent. Results JAl not only had significant anti-proliferative effects depending upon time and dosage, but also induced apoptosis of HepG2 cells. Apoptotic typical morphological changes were observed in JAl-treated HepG2 cells under transmission electronic microscope, ＂Sub-G 1＂ phase peak occurred in flow cytometry and DNA ＂ladder＂ was found in DNA agarose gel electrophoresis. The expression of the wt-p53 increased in vitro, and 3Al-treated HepG2 and the positive cell percentage of the wt-p53 protein also increased. Conclusions JAl could obviously induce apoptosis and inhibit proliferation of HepG2 cells in vitro, and these effects are closely related with the increase of wt-p53 expression. JAl can be used as a good source of medicinal plant for the treatment of hepatocarcinoma.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.30671476 and 30271067).
文摘Cold acclimation is associated with many metabolic changes that lead to an increase of freezing tolerance. In order to investigate the biochemical process of cold acclimation in Ammopiptanthus mongolicus, seedlings were acclimated at 2℃ under 16-h photoperiod （150 μmol·m^-2·s^-1 photosynthetically active radiation） for 14 d. Freezing tolerance in seedlings increased after 14 d of cold-hardening. Contents of protein, proline and solute carbohydrate in cotyledon increased after cold acclimation. Patterns of isozymes of superoxide dismutase （SOD）, peroxidase, catalase and polyphenol oxidase （PPO） were investigated. The activities of SOD, peroxidase and PPO in cold acclimated plants were increased during cold-hardening. We deduced that compatible solutes and antioxidant enzymes play important roles in development of freezing tolerance during cold acclimation in this evergreen woody plant.
文摘Ammopiptanthus mongolicus is the only evergreen broadleaved shrub endemic species to the Alashan Desert, northwest sand area of China, and can survive at -30℃ or even lower temperature in winter. A modified solid-phase subtraction hybridization technique was developed to isolate and screen cDNAs, whose transcripts increased in cold-treated A. mongolicus seedlings. Sequence analysis of the screened clones indicated that 11 clones had coding regions, with four of them containing complete open reading frame. And nine of the 11 clones shared various degrees of homology with the genes found in the GenBank database and the other two were unidentified sequences. Sequence data further revealed that these accumulated transcripts encode three low molecular weight proteins, a late-embryogenesis protein and two cold acclimation responsive proteins; two photosynthesis-related proteins, photosystem I subunit II precursor (PsaD) and photosystem II oxygen-evolving complex 33kDa subunit (OEC33); a protease inhibitor; an adenosine triphosphatase and a 14-3-3 related protein. Analysis on the function of these proteins indicated that the low molecular weight proteins were associated with water holding ability of cytoplasm; photosynthesis-related proteins participated in the adjustments of photosynthetic apparatus to resist photoinhibition; 14-3-3 related protein could interact with adenosine triphosphatase to enhance ATPase activity and energy metabolism; and protease inhibitor involved in the prevention of unwanted cell death was caused by reactive oxygen species. We suggest that cold acclimation with low light intensity in A. mongolicus is a more complex interaction of low temperature, light, energy and signal than that assumed previously.
基金the National Natural Science Foundation of China （Grant No. 30671476 , 30271067）.
文摘Ammopiptanthus mongolicus, the only freezing tolerant evergreen broad-leaved shrub, local species of the Alashan desert, northwest sand area of China, can survive -30℃ or even lower temperature in winter. In the present study, the secondary products phenolics in A. mongolicus cotyledons were determined to study the effects of phenolics on cold tolerance. Cytochemical localization of phenolics in cotyledon cells was observed by electron microscopy and the content of phenolic compounds was assayed by spectrophotometric measurement. The results showed that the freezing tolerance ofA. mongolicus seedlings increased after acclimation at 2℃ for 14 days, which accompanied the increase of the content of phenolic compounds in cotyledons. Cytochemical observation showed that phenolic deposits were mainly localized in vacuoles and in close proximity to tonoplast, and also in the cytoplasm. The amount and the size of phenolics droplets increased obviously in cytoplasm and vacuoles after cold acclimation, predominantly aggregated along membranes of vacuoles and tonoplast. No phenolic deposits were found in cell walls. As hydrogen- or elec- tron-donating agents, phenolics may protect plant cells against reactive oxygen species formed during chilling or freezing stress and improve the freezing tolerance of cold-acclimated A. mongolicus seedlings.
