The seed cotyledons of a euhalophyte, Suaeda physophora, were found to be dark green. The pigment extracted from the cotyledons was proved to be chlorophyll for the absorption spectra curve of extracts the same as tha...The seed cotyledons of a euhalophyte, Suaeda physophora, were found to be dark green. The pigment extracted from the cotyledons was proved to be chlorophyll for the absorption spectra curve of extracts the same as that for leaves. Photosynthetic oxygen-exchanging could be detected after the seeds were moistened for 6 h. Microstructure of organelles in cotyledons of ungerminated seeds was detected by transmission electron microscopy. Histochemical pigmentation was used to investigate the degree of damage on the membrane of radicles. A xerophyte, Haloxylon persicum, whose cotyledons of desiccated seeds also contain chlorophyll was used as a comparative species. The results showed that S. physophora maintained the ultra-structure of chloroplasts, the integrity of plasma membranes of radicles kept much better than that of H. persicum, which showed the great adaptability to salinity of the euhalophyte even at the seed-germination stage. Seeds were incubated in 0 and 700 mmol/L NaCl for 10 days in darkness at 20 ℃ , then ungerminated seeds in NaCl solution were transferred to deionised water and reincubated for another 8 days and was recorded the germination recovery. Dry seeds moistened with deionised water germinated gradually in the dark and germination was maximal after 3 or 4 d. Seeds at 700 mmol/L NaCl for 10 d and transferred back to deionised water germinated abruptly, most seeds germinated in one day and photosynthesis was also detected. It is concluded that recovery germination of S. physophora ensured the seeds could germinate rapidly after salinity declines, for example under the mild but transitory favorable edaphic condition in early spring. Photosynthesis function in seeds might also promoted radicle growth and seedling establishment.展开更多
Suaeda physophora Pall.is a kind of desert plant mostly growing in saline habitats in Xinjiang Uygur Autonomous Region.In order to have a better utilization of halophytes,a screening for ACE inhibitors from halophytes...Suaeda physophora Pall.is a kind of desert plant mostly growing in saline habitats in Xinjiang Uygur Autonomous Region.In order to have a better utilization of halophytes,a screening for ACE inhibitors from halophytes growing in Xinjiang was carried out.The result showed that the 70%EtOH extract and n-BuOH extract of S.physophora Pall.possessed significant ACE inhibitory activities.So we focused on its biochemical constituents firstly.One new quinazoline alkaloid,namely Suaedine(1),along with six known compounds(2–7)was isolated from the aerial parts of S.physophora Pall.The structure of the new quinazoline alkaloid was established by one-and two-dimensional nuclear magnetic resonance,optical rotation and mass spectrometry analysis.The flavonoid compounds(2–4)and phenolic compound(5)exhibited significant ACE activities.It was the first time to focus on the chemical constituents and bioactivities of this plant.展开更多
Aims We investigated the impact of salinity on seed germination,chlorophyll content,chloroplast structure and photosynthesis of the green embryos in desiccated seeds of the xerophyte Haloxylon persicum,xero-halophyte ...Aims We investigated the impact of salinity on seed germination,chlorophyll content,chloroplast structure and photosynthesis of the green embryos in desiccated seeds of the xerophyte Haloxylon persicum,xero-halophyte Haloxylon ammodendron and euhalophyte Suaeda physophora.Methods Seeds of H.persicum,H.ammodendron and S.physophora were collected from natural environment in Fukang,Xinjiang province.Pretreatment with 700 mM NaCl was carried out to stimulate the natural‘seed priming’;we analyzed the joint effect of salinity and different species on germination physiology and cotyledonal structure and photosynthetic function changes during germination and recovery stage.Important Findings We found that seeds did not suffer ion toxicity for the two halophytes H.ammodendron and S.physophora,as evidenced by the high final germination after ungerminated seeds pretreated with 700 mM NaCl were transferred to distilled water,but the final germination of the xerophyte H.persicum was significantly lower than that of control.The Na+concentration in embryos increased under salinity for all species,while K+concentration decreased by salinity only for H.persicum and H.ammodendron,i.e.the concentration of K+in embryos of H.persicum and H.ammodendron decreased by 36%and 46%,respectively.For all species,whether dry intact seeds or cotyledons of dry seeds imbibed in deionized water and NaCl solution,had high chlorophyll content.Treatment with NaCl also caused chloroplast thylakoids to swell and chlorophyll content to decrease in seeds of H.persicum,but no significant change was observed in the more salt-tolerant species S.physophora and H.ammodendron.Fluorescence measurement showed that 700 mM NaCl decreased the Fv/Fm ratio of cotyledons in seeds for all species,especially for H.persicum and H.ammodendron.Photosynthetic oxygen releasing was detected from the seeds that were moistened with distilled water and 700 mM NaCl for 6 or 24 h and from the seeds that were initially moistened with 700 mM NaCl in darkness for 10 days,then tra展开更多
Na+ ions play an important role in the growth of halophyte. The effect of Na+ ions on nitrate uptake and osmotic adjustment in the euhalophyte Suaeda physophora was investigated under glasshouse conditions. Seedlings ...Na+ ions play an important role in the growth of halophyte. The effect of Na+ ions on nitrate uptake and osmotic adjustment in the euhalophyte Suaeda physophora was investigated under glasshouse conditions. Seedlings were exposed to 1 mmol/L NaCl (control),300 mmol/L NaCl,150 mmol/L NaCl plus 150 mmol/L KCl or 300 mmol/L KCl treatments for 24 d. Dry weight was not affected greatly by different salt treatments,but water content and succulence in leaves of S. physophora were significantly increased at 300 mmol/L NaCl and 150 mmol/L NaCl plus 150 mmol/L KCl treatments. The concentrations of Na+ and NO3’ in leaves of S. physophora were the highest at 150 mmol/L NaCl plus 150 mmol/L KCl,but lowest at 300 mmol/L KCl treatment. Moreover,the increase of NO3’ concentration did not result in the decrease of Cl-concentration at 150 mmol/L NaCl plus 150 mmol/L KCl treatments. The estimated contribution of NO3’ to osmotic potential (CNO3) in leaves of S. physophora was 9.8% at 150 mmol/L NaCl plus 150 mmol/L KCl,and CNa and CCl were 31.0% and 23.3%,respectively. However,CNO3,CNa and CCl were respectively 1.6%,7.9% and 11.9% at 300 mmol/L KCl treatment. It is concluded that Na+ stimulates NO3’ absorption and the stimulation is independent on the internal or the external Cl-concentration in the euhalophyte S. physo-phora. These characteristics may explain the high levels of N in leaves of saline desert plants in arid ecosystem.展开更多
基金the National Natural Science Foundation of China (Grant No. 30770341)Key Programs of Xinjiang Autonomous Region of China (Grant No. 200533124)Chinese Scholarship Council.
文摘The seed cotyledons of a euhalophyte, Suaeda physophora, were found to be dark green. The pigment extracted from the cotyledons was proved to be chlorophyll for the absorption spectra curve of extracts the same as that for leaves. Photosynthetic oxygen-exchanging could be detected after the seeds were moistened for 6 h. Microstructure of organelles in cotyledons of ungerminated seeds was detected by transmission electron microscopy. Histochemical pigmentation was used to investigate the degree of damage on the membrane of radicles. A xerophyte, Haloxylon persicum, whose cotyledons of desiccated seeds also contain chlorophyll was used as a comparative species. The results showed that S. physophora maintained the ultra-structure of chloroplasts, the integrity of plasma membranes of radicles kept much better than that of H. persicum, which showed the great adaptability to salinity of the euhalophyte even at the seed-germination stage. Seeds were incubated in 0 and 700 mmol/L NaCl for 10 days in darkness at 20 ℃ , then ungerminated seeds in NaCl solution were transferred to deionised water and reincubated for another 8 days and was recorded the germination recovery. Dry seeds moistened with deionised water germinated gradually in the dark and germination was maximal after 3 or 4 d. Seeds at 700 mmol/L NaCl for 10 d and transferred back to deionised water germinated abruptly, most seeds germinated in one day and photosynthesis was also detected. It is concluded that recovery germination of S. physophora ensured the seeds could germinate rapidly after salinity declines, for example under the mild but transitory favorable edaphic condition in early spring. Photosynthesis function in seeds might also promoted radicle growth and seedling establishment.
基金supported by the National Natural Science Foundation of China(81001371)the Science and Technology Foundation of Dalian city(2011J21DW012).
文摘Suaeda physophora Pall.is a kind of desert plant mostly growing in saline habitats in Xinjiang Uygur Autonomous Region.In order to have a better utilization of halophytes,a screening for ACE inhibitors from halophytes growing in Xinjiang was carried out.The result showed that the 70%EtOH extract and n-BuOH extract of S.physophora Pall.possessed significant ACE inhibitory activities.So we focused on its biochemical constituents firstly.One new quinazoline alkaloid,namely Suaedine(1),along with six known compounds(2–7)was isolated from the aerial parts of S.physophora Pall.The structure of the new quinazoline alkaloid was established by one-and two-dimensional nuclear magnetic resonance,optical rotation and mass spectrometry analysis.The flavonoid compounds(2–4)and phenolic compound(5)exhibited significant ACE activities.It was the first time to focus on the chemical constituents and bioactivities of this plant.
文摘Aims We investigated the impact of salinity on seed germination,chlorophyll content,chloroplast structure and photosynthesis of the green embryos in desiccated seeds of the xerophyte Haloxylon persicum,xero-halophyte Haloxylon ammodendron and euhalophyte Suaeda physophora.Methods Seeds of H.persicum,H.ammodendron and S.physophora were collected from natural environment in Fukang,Xinjiang province.Pretreatment with 700 mM NaCl was carried out to stimulate the natural‘seed priming’;we analyzed the joint effect of salinity and different species on germination physiology and cotyledonal structure and photosynthetic function changes during germination and recovery stage.Important Findings We found that seeds did not suffer ion toxicity for the two halophytes H.ammodendron and S.physophora,as evidenced by the high final germination after ungerminated seeds pretreated with 700 mM NaCl were transferred to distilled water,but the final germination of the xerophyte H.persicum was significantly lower than that of control.The Na+concentration in embryos increased under salinity for all species,while K+concentration decreased by salinity only for H.persicum and H.ammodendron,i.e.the concentration of K+in embryos of H.persicum and H.ammodendron decreased by 36%and 46%,respectively.For all species,whether dry intact seeds or cotyledons of dry seeds imbibed in deionized water and NaCl solution,had high chlorophyll content.Treatment with NaCl also caused chloroplast thylakoids to swell and chlorophyll content to decrease in seeds of H.persicum,but no significant change was observed in the more salt-tolerant species S.physophora and H.ammodendron.Fluorescence measurement showed that 700 mM NaCl decreased the Fv/Fm ratio of cotyledons in seeds for all species,especially for H.persicum and H.ammodendron.Photosynthetic oxygen releasing was detected from the seeds that were moistened with distilled water and 700 mM NaCl for 6 or 24 h and from the seeds that were initially moistened with 700 mM NaCl in darkness for 10 days,then tra
基金supported by the Key Technology Program of the Xinjiang Uygur Autonomous Region,China (200733144-1)the Knowledge Innovation Project of the Chinese of Academy of Sciences (KSCX2-YW-N-41)
文摘Na+ ions play an important role in the growth of halophyte. The effect of Na+ ions on nitrate uptake and osmotic adjustment in the euhalophyte Suaeda physophora was investigated under glasshouse conditions. Seedlings were exposed to 1 mmol/L NaCl (control),300 mmol/L NaCl,150 mmol/L NaCl plus 150 mmol/L KCl or 300 mmol/L KCl treatments for 24 d. Dry weight was not affected greatly by different salt treatments,but water content and succulence in leaves of S. physophora were significantly increased at 300 mmol/L NaCl and 150 mmol/L NaCl plus 150 mmol/L KCl treatments. The concentrations of Na+ and NO3’ in leaves of S. physophora were the highest at 150 mmol/L NaCl plus 150 mmol/L KCl,but lowest at 300 mmol/L KCl treatment. Moreover,the increase of NO3’ concentration did not result in the decrease of Cl-concentration at 150 mmol/L NaCl plus 150 mmol/L KCl treatments. The estimated contribution of NO3’ to osmotic potential (CNO3) in leaves of S. physophora was 9.8% at 150 mmol/L NaCl plus 150 mmol/L KCl,and CNa and CCl were 31.0% and 23.3%,respectively. However,CNO3,CNa and CCl were respectively 1.6%,7.9% and 11.9% at 300 mmol/L KCl treatment. It is concluded that Na+ stimulates NO3’ absorption and the stimulation is independent on the internal or the external Cl-concentration in the euhalophyte S. physo-phora. These characteristics may explain the high levels of N in leaves of saline desert plants in arid ecosystem.
