Water relations of Alhagi sparsifolia Shap. at the transition zone between oases and sandy desert were studied in the southern fringe of Taklamakan Desert. Results showed that A. sparsifolia maintained the positive tu...Water relations of Alhagi sparsifolia Shap. at the transition zone between oases and sandy desert were studied in the southern fringe of Taklamakan Desert. Results showed that A. sparsifolia maintained the positive turgor during the summer. The steady high predawn water potential (psi(P)) indicated A. sparsifolia had sufficient hydration and water supply in growing season. In July, water deficit caused by drought stress had no effect on the transpiration of A. sparsifolia. Therefore, drought stress is not a main factor affecting the survival of plants. The physiological adaptation to drought of A. sparsifolia was shown mainly at the leaf level by significant difference (DeltaII) and relative water content (RWC) between the osmotic pressure at full turgor and at turgor loss, by occurring of osmotic adjustment, by high percentage of dry mass-related water content ( WCsat), by RWC at turgor loss point ( RWCp) in stable level and low RWC of the saturated symplast (RWCsym). However, the morphological features of transpiring surface reduction and deep root system seem to be the main way for the plant to adapt to the extreme drought environment. Result also suggests that one time of irregular irrigation in summer will not be helpful to recover water status of A. sparsifolia in location where the water table is very low.展开更多
Soil salinity is one of the most important environmental factors limiting plant growth and productivity in many regions in the world. Salt stress directly affects plant photosynthesis, which is an important physiologi...Soil salinity is one of the most important environmental factors limiting plant growth and productivity in many regions in the world. Salt stress directly affects plant photosynthesis, which is an important physiological process to limit plant growth and crop yield. But the effects of salt stress on the mechanism of the photosynthesis is still not clear. In this experiment, the salt tolerant plant Alhagi pseudalhagi was selected as the experiment material, and the salt sensitive plant Vigna radiata as the control, to explore the effects of salt stress on photosynthetic parameters of A. pseudalhagi. Plants were grown in a greenhouse,cultured with 1/2 Hoagland nutrient solution, treated by 0(control), 50, 100 or 200 s of mmol/L of NaCl solution for 12 d. Then,the chlorophyll contents, gas exchange parameters and chlorophyll a fluorescence in each treatment were measured. The results showed that under the salt stress simulated by 50 mmol/L NaCl, the net photosynthetic rate(Pn) and stomatal conductance(gs)of A. pseudalhagi were significantly increased compared with the control, while intercellular CO_2 concentration(Ci) was significantly decreased, Fv'/Fm', Fv/Fm and Fv/Fo were increased over time, but had no significant differences with the control ФPSⅡ,ETR and qP were significantly increased, and NPQ was significantly decreased. Under the salt stress simulated by 100 and 200mmol/L NaCl, Fv'/Fm', Fv/Fm, Fv/Fo, ФPSⅡ and qP of A. pseudalhagi were gradually decreased over time. In contrary, under the salt stress simulated by 50 and 100 mmol/L NaCl, the Pn, gs, Ci, Fv'/Fm', Fv/Fm, Fv/Fo, ФPSII, qP and ETR were all significantly decreased, while NPQ was significantly increased.展开更多
Alhagi sparsifolia Shap. （Fabaceae） is a spiny, perennial herb. The species grows in the salinized, arid regions in North China. This study investigated the response characteristics of the root growth and the dis- t...Alhagi sparsifolia Shap. （Fabaceae） is a spiny, perennial herb. The species grows in the salinized, arid regions in North China. This study investigated the response characteristics of the root growth and the dis- tribution of one-year-old A. sparsifolia seedlings to different groundwater depths in controlled plots. The eco- logical adaptability of the root systems of A. sparsifolia seedlings was examined using the artificial digging method. Results showed that： （1） A. sparsifolia seedlings adapted to an increase in groundwater depth mainly through increasing the penetration depth and growth rate of vertical roots. The vertical roots grew rapidly when soil moisture content reached 3%-9%, but slowly when soil moisture content was 13%-20%. The vertical roots stopped growing when soil moisture content reached 30% （the critical soil moisture point）. （2） The morphological plasticity of roots is an important strategy used by A. sparsifolia seedlings to obtain water and adapt to dry soil conditions. When the groundwater table was shallow, horizontal roots quickly expanded and tillering increased in order to compete for light resources, whereas when the groundwater table was deeper, vertical roots developed quickly to exploit space in the deeper soil layers. （3） The decrease in groundwater depth was probably respon- sible for the root distribution in the shallow soil layers. Root biomass and surface area both decreased with soil depth. One strategy of A. sparsifolia seedlings in dealing with the increase in groundwater depth is to increase root biomass in the deep soil layers. The relationship between the root growth/distribution of A. sparsifolia and the depth of groundwater table can be used as guidance for harvesting A. sparsifolia biomass and managing water resources for forage grasses. It is also of ecological significance as it reveals how desert plants adapt to arid environments.展开更多
The effect of variation in water supply on woody seedling growth in arid environments remain poorly known.The subshrub Alhagi sparsifolia Shap.（Leguminosae）,distributed in the southern fringe of the Taklimakan Deser...The effect of variation in water supply on woody seedling growth in arid environments remain poorly known.The subshrub Alhagi sparsifolia Shap.（Leguminosae）,distributed in the southern fringe of the Taklimakan Desert,Xinjiang,northwestern China,has evolved deep roots and is exclusively dependent on groundwater,and performs a crucial role for the local ecological safety.In the Cele oasis,we studied the responses of A.sparsifolia seedling roots to water supplement at 10 and 14 weeks under three irrigation treatments （none water supply of 0 m3/m2 （NW）,middle water supply of 0.1 m3/m2 （MW）,and high water supply of 0.2 m3/m2 （HW））.The results showed that the variations of soil water content （SWC） significantly influenced the root growth of A.sparsifolia seedlings.The leaf area,basal diameter and crown diameter were significantly higher in the HW treatment than in the other treatments.The biomass,root surface area （RSA）,root depth and relative growth rate （RGR） of A.sparsifolia roots were all significantly higher in the NW treatment than in the HW and MW treatments at 10 weeks.However,these root parameters were significantly lower in the NW treatment than in the other treatments at 14 weeks.When SWC continued to decline as the experiment went on （until less than 8％ gravimetric SWC）,the seedlings still showed drought tolerance through morphological and physiological responses,but root growth suffered serious water stress compared to better water supply treatments.According to our study,keeping a minimum gravimetric SWC of 8％ might be important for the growth and establishment of A.sparsifolia during the early growth stage.These results will not only enrich our knowledge of the responses of woody seedlings to various water availabilities,but also provide a new insight to successfully establish and manage A.sparsifolia in arid environments,further supporting the sustainable development of oases.展开更多
The legume forage Alhagi pseudoalhagi was transformed by the Agrobacterium rhizogenes strain A4 using cotyledon and hypocotyl segments as infection materials. Regenerated plants were achieved from sterile calli derive...The legume forage Alhagi pseudoalhagi was transformed by the Agrobacterium rhizogenes strain A4 using cotyledon and hypocotyl segments as infection materials. Regenerated plants were achieved from sterile calli derived from hairy roots, which occurred at or near the infection sites. The regenerated plants from hairy root were characterized by normal leaf morphology and stem growth but a shallow and more extensive root system than normal plants. Opine synthesis, PCR and Southern blot confirmed that T- DNA had been integrated into the A. pseudoalhagi genome. Acetosyringone (AS) was found to be vital for successful transformation of A. pseudoalhagi.展开更多
In this study, the desirability function approach was used to simultaneously optimize multiple factors. The variables evaluated were combinations of growth regulators, media and organs in affecting the organogenesis o...In this study, the desirability function approach was used to simultaneously optimize multiple factors. The variables evaluated were combinations of growth regulators, media and organs in affecting the organogenesis of Alhagi. In the first step of this study, various experiments were carried out in order to optimize the callus induction and its growth. The highest rate of callus induction was achieved from the leaf segment on MS medium supplemented with 3 mg·l-1 BAP + 6 mg·l-1 NAA. Moreover, the highest rate of regeneration was recorded on MS medium supplemented with those 4 mg·l-1 BAP using for leaf segments. The optimized condition of roots induction per shoot was observed in the 1/4 MS medium without activated charcoal and supplemented with 0.25 mg·l-1 IAA. The well rooted plantlets were acclimatized and successfully established into soil where 70% plantlets were survived. The data indicate that media, BAP, and NAA levels may be manipulated to increase or decrease quality factors chosen.展开更多
[ Objective] The aim was to establish effective method for endogenous hormone extraction and explore conditions of chromatographic analysis for three endogenous hormones in rhizome of Alhagi sparsifolia. [ Methed ] Ac...[ Objective] The aim was to establish effective method for endogenous hormone extraction and explore conditions of chromatographic analysis for three endogenous hormones in rhizome of Alhagi sparsifolia. [ Methed ] Activol （GA3 ）, zeatin （ZR） and indole-3-acetic acid （IAA） in rhizome were separated and measured as per RP-HPLC. [Result] The average recovery rates of GA3, ZR and IAA were 98.3%, 90.3% and 101.3%, respectively, indicating that the method is suitable for quantitative analysis with little errors. The chromatographic conditions were as follows： methanol/0. 75% of acetic acid at 45：55 （mobile phase） ; flow speed at 0.7 ml/min; wavelength at 254 nm; column temperature at 25 ℃. [Conclusion] The research preliminarily established HPLC conditions for separation of endogenous hormones in rhizome of Alhagi sparsifolia.展开更多
Alhagi sparsifolia is a leguminous perennial desert species that is plays an important role in dune stabilization and revegetation of degraded desert ecosystems. We investigated the effects of three different levels o...Alhagi sparsifolia is a leguminous perennial desert species that is plays an important role in dune stabilization and revegetation of degraded desert ecosystems. We investigated the effects of three different levels of salinity (50, 150, 250 mmol/L NaCl) on the growth, shoot photosynthetic parameters and salt distribution amongst different plant organs in one-year-old A. sparsifolia seedlings in a pot experiment over a 50 d period. The minimum (predawn) and maximum (midday) water potentials of A. sparsifolia seedlings decreased with the increase of external NaCl concentrations as a consequence of the osmotic or water deficit effect of saline solutions outside the roots. Salinity also reduced gas exchange parameters in A. sparsifolia, with seedlings subjected to salinity having lower photosynthesis rates and reduced stomatal conductances compared to the control. The reductions in photosynthetic rates in high salinity treatments of the A. sparsifolia seedlings were mainly caused by stomatal limitation. Consequently plants growing at greater external NaCl concentrations had significantly lower biomass accumulation compared to the control grown at 50 mmol/L. However, plants exposed to higher salinity were able to maintain growth throughout the experiment but allocated a greater proportion of biomass belowground. Plants exposed to higher external salinity levels had increased concentrations of Na+ and Cl- ions in shoots and roots, suggesting that A. sparsifolia seedlings were utilizing Na+ and Cl- as osmolytes to increase the cellular osmolality and decrease their water potential. We observed the greatest NaCl concentrations in the plants treated with 150 mmol/L NaCl indicating that there may be a threshold level of NaCl that can be tolerated by the plants. In conclusion our results indicate that A. sparsifolia seedlings are moderately salt tolerant. Photosynthetic gas exchange parameters were reduced by greater external salinity but the seedlings maintained substantial photosynthetic rates even under high salinity stress, were able to maintain growth over the 50 d experimental period and showed no signs of salinity toxicity or damage.展开更多
Water relation characteristics of the desert legume Alhagi sparsifolia were investigated during the vegetation period from April to September 1999 in the foreland of Qira oasis at the southern fringe of the Taklamakan...Water relation characteristics of the desert legume Alhagi sparsifolia were investigated during the vegetation period from April to September 1999 in the foreland of Qira oasis at the southern fringe of the Taklamakan Desert, Xinjiang Uygur Autonomous Region of China. The sea- sonal variation of predawn water potentials and of diurnal water potential indicated that Alhagi plants were well water supplied over the entire vegetation period. Decreasing values in the sum- mer months were probably attributed to increasing temperatures and irradiation and therefore a higher evapotranspirative demand. Data from pressure-volume analysis confirmed that Alhagi plants were not drought stressed and xylem sap flow measurements indicated that Alhagi plants used large amounts of water during the summer months. Flood irrigation had no influence on water relations in Alhagi probably because Alhagi plants produced only few fine roots in the upper soil layers. The data indicate that Alhagi sparsifolia is a drought-avoiding species that utilizes ground water by a deep roots system, which is the key characteristic to adjust the hyper-arid environment. Because growth and survival of Alhagi depends on ground water supply, it is important that varia- tions of ground water depth are kept to a minimum. The study will provide a theoretical basis for the restoration and management of natural vegetation around oasis in arid regions.展开更多
We report the recovery of a 7068-nt viral sequence from the ＂viral fossils＂ embedded in the genome of Alhagi sparsifolia, a typical desert plant. Although the full viral genome remains to be completed, the putative ...We report the recovery of a 7068-nt viral sequence from the ＂viral fossils＂ embedded in the genome of Alhagi sparsifolia, a typical desert plant. Although the full viral genome remains to be completed, the putative genome structure, the deduced amino acids and phylogenetic analysis unambiguously demonstrate that this viral sequence represents a novel species of the genus Badnavirus. The putative virus is tentatively termed Alhagi bacilliform virus （ABV）. Southern blotting and inverse polymerase chain reaction （PCR） data indicate that the ABV-related sequence is integrated into the A. sparsifolia genome, and probably does not give rise to functional episomal virus. Molecular evidence that the ABV sequence exists widely in A. sparsifolia is also presented. To our knowledge, this is the first endogenous badnavirus identified from plants in the Gobi desert, and may provide new clues on the evolution, geo- graphical distribution as well as the host range of the badnaviruses.展开更多
Objectives:While the protective effects of Alhagi maurorum have been shown against various ailments,its role against norfloxacin-induced adverse effects has not been studied.The current study was conducted to determin...Objectives:While the protective effects of Alhagi maurorum have been shown against various ailments,its role against norfloxacin-induced adverse effects has not been studied.The current study was conducted to determine the effect of A.maurorum aqueous extract against norfloxacin-induced side effects in rats.Methods:Twenty-four male albino rats were randomly assigned into four groups,which received normal saline,norfloxacin(50 mg/kg b.wt orally once a day),A.maurorum aqueous extract(300 mg/kg b.wt orally once a day),and norfloxacin with A.maurorum aqueous extract by the same previous mentioned dosages.Blood samples were collected for hematological examination to evaluate liver and kidney function tests.Hepatic and renal tissue samples were obtained to assess antioxidant activity and histopathological examination.Results:A.maurorum aqueous extract significantly ameliorated norfloxacin-induced elevation in tissue malondialdehyde,and reduction in tissue antioxidant enzymes such as catalase,glutathione peroxidase,and superoxide dismutase activities as well as reduced glutathione concentration.Concurrent administration of A.maurorum aqueous extract with norfloxacin significantly reduced serum alkaline phosphatase,aminotransferases,urea,creatinine,and uric acid and increased RBCs count,Hb concentration,PCV,leucocyte,and monocyte counts compared with the norfloxacin-treated group.Co-administration of A.maurorum aqueous extract with norfloxacin prevented the degenerative changes induced by norfloxacin alone in liver and kidney tissues.The phytochemical profile of the extract showed the presence of carbohydrates,alkaloids,saponins,tannins,phenolics,and flavonoids.Conclusion:These findings indicated that A.maurorum possesses potent antioxidant activities and could be used to attenuate norfloxacin-induced side effects.展开更多
文摘Water relations of Alhagi sparsifolia Shap. at the transition zone between oases and sandy desert were studied in the southern fringe of Taklamakan Desert. Results showed that A. sparsifolia maintained the positive turgor during the summer. The steady high predawn water potential (psi(P)) indicated A. sparsifolia had sufficient hydration and water supply in growing season. In July, water deficit caused by drought stress had no effect on the transpiration of A. sparsifolia. Therefore, drought stress is not a main factor affecting the survival of plants. The physiological adaptation to drought of A. sparsifolia was shown mainly at the leaf level by significant difference (DeltaII) and relative water content (RWC) between the osmotic pressure at full turgor and at turgor loss, by occurring of osmotic adjustment, by high percentage of dry mass-related water content ( WCsat), by RWC at turgor loss point ( RWCp) in stable level and low RWC of the saturated symplast (RWCsym). However, the morphological features of transpiring surface reduction and deep root system seem to be the main way for the plant to adapt to the extreme drought environment. Result also suggests that one time of irregular irrigation in summer will not be helpful to recover water status of A. sparsifolia in location where the water table is very low.
基金Supported by China Agricultural University-Xinjiang Agricultural University Scientific Research Cooperation Fund Projects:Cloning and the Functional Analysis of Main Salinity and Water Stress Resistant Gene in Alhagi pseudoalhagiXinjiang Anjudan Biotechnology Co.,Ltd.(Anjudan Green Life 2016-001)
文摘Soil salinity is one of the most important environmental factors limiting plant growth and productivity in many regions in the world. Salt stress directly affects plant photosynthesis, which is an important physiological process to limit plant growth and crop yield. But the effects of salt stress on the mechanism of the photosynthesis is still not clear. In this experiment, the salt tolerant plant Alhagi pseudalhagi was selected as the experiment material, and the salt sensitive plant Vigna radiata as the control, to explore the effects of salt stress on photosynthetic parameters of A. pseudalhagi. Plants were grown in a greenhouse,cultured with 1/2 Hoagland nutrient solution, treated by 0(control), 50, 100 or 200 s of mmol/L of NaCl solution for 12 d. Then,the chlorophyll contents, gas exchange parameters and chlorophyll a fluorescence in each treatment were measured. The results showed that under the salt stress simulated by 50 mmol/L NaCl, the net photosynthetic rate(Pn) and stomatal conductance(gs)of A. pseudalhagi were significantly increased compared with the control, while intercellular CO_2 concentration(Ci) was significantly decreased, Fv'/Fm', Fv/Fm and Fv/Fo were increased over time, but had no significant differences with the control ФPSⅡ,ETR and qP were significantly increased, and NPQ was significantly decreased. Under the salt stress simulated by 100 and 200mmol/L NaCl, Fv'/Fm', Fv/Fm, Fv/Fo, ФPSⅡ and qP of A. pseudalhagi were gradually decreased over time. In contrary, under the salt stress simulated by 50 and 100 mmol/L NaCl, the Pn, gs, Ci, Fv'/Fm', Fv/Fm, Fv/Fo, ФPSII, qP and ETR were all significantly decreased, while NPQ was significantly increased.
基金supported by the Knowledge Innovation Program of the Chinese Academy of Sciences (KZCX2-EW-316)the National Natural Science Foundation of China (31070477,30870471)the West Light Foundation of the Chinese Academy of Sciences (XBBS201105)
文摘Alhagi sparsifolia Shap. （Fabaceae） is a spiny, perennial herb. The species grows in the salinized, arid regions in North China. This study investigated the response characteristics of the root growth and the dis- tribution of one-year-old A. sparsifolia seedlings to different groundwater depths in controlled plots. The eco- logical adaptability of the root systems of A. sparsifolia seedlings was examined using the artificial digging method. Results showed that： （1） A. sparsifolia seedlings adapted to an increase in groundwater depth mainly through increasing the penetration depth and growth rate of vertical roots. The vertical roots grew rapidly when soil moisture content reached 3%-9%, but slowly when soil moisture content was 13%-20%. The vertical roots stopped growing when soil moisture content reached 30% （the critical soil moisture point）. （2） The morphological plasticity of roots is an important strategy used by A. sparsifolia seedlings to obtain water and adapt to dry soil conditions. When the groundwater table was shallow, horizontal roots quickly expanded and tillering increased in order to compete for light resources, whereas when the groundwater table was deeper, vertical roots developed quickly to exploit space in the deeper soil layers. （3） The decrease in groundwater depth was probably respon- sible for the root distribution in the shallow soil layers. Root biomass and surface area both decreased with soil depth. One strategy of A. sparsifolia seedlings in dealing with the increase in groundwater depth is to increase root biomass in the deep soil layers. The relationship between the root growth/distribution of A. sparsifolia and the depth of groundwater table can be used as guidance for harvesting A. sparsifolia biomass and managing water resources for forage grasses. It is also of ecological significance as it reveals how desert plants adapt to arid environments.
基金funded by the Knowledge Innovation Program of the Chinese Academy of Sciences(KZCX2-EW-316)the National Natural Science Foundation of China(41001171,31070477,30870471)+2 种基金the Western Light Foundation of the Chinese Academy of Sciences(XBBS201105)the Key Program of Joint Funds of the National Natural Science Foundation of Chinathe Government of Xinjiang Uygur Autonomous Region of China(U1203201)
文摘The effect of variation in water supply on woody seedling growth in arid environments remain poorly known.The subshrub Alhagi sparsifolia Shap.（Leguminosae）,distributed in the southern fringe of the Taklimakan Desert,Xinjiang,northwestern China,has evolved deep roots and is exclusively dependent on groundwater,and performs a crucial role for the local ecological safety.In the Cele oasis,we studied the responses of A.sparsifolia seedling roots to water supplement at 10 and 14 weeks under three irrigation treatments （none water supply of 0 m3/m2 （NW）,middle water supply of 0.1 m3/m2 （MW）,and high water supply of 0.2 m3/m2 （HW））.The results showed that the variations of soil water content （SWC） significantly influenced the root growth of A.sparsifolia seedlings.The leaf area,basal diameter and crown diameter were significantly higher in the HW treatment than in the other treatments.The biomass,root surface area （RSA）,root depth and relative growth rate （RGR） of A.sparsifolia roots were all significantly higher in the NW treatment than in the HW and MW treatments at 10 weeks.However,these root parameters were significantly lower in the NW treatment than in the other treatments at 14 weeks.When SWC continued to decline as the experiment went on （until less than 8％ gravimetric SWC）,the seedlings still showed drought tolerance through morphological and physiological responses,but root growth suffered serious water stress compared to better water supply treatments.According to our study,keeping a minimum gravimetric SWC of 8％ might be important for the growth and establishment of A.sparsifolia during the early growth stage.These results will not only enrich our knowledge of the responses of woody seedlings to various water availabilities,but also provide a new insight to successfully establish and manage A.sparsifolia in arid environments,further supporting the sustainable development of oases.
文摘The legume forage Alhagi pseudoalhagi was transformed by the Agrobacterium rhizogenes strain A4 using cotyledon and hypocotyl segments as infection materials. Regenerated plants were achieved from sterile calli derived from hairy roots, which occurred at or near the infection sites. The regenerated plants from hairy root were characterized by normal leaf morphology and stem growth but a shallow and more extensive root system than normal plants. Opine synthesis, PCR and Southern blot confirmed that T- DNA had been integrated into the A. pseudoalhagi genome. Acetosyringone (AS) was found to be vital for successful transformation of A. pseudoalhagi.
文摘In this study, the desirability function approach was used to simultaneously optimize multiple factors. The variables evaluated were combinations of growth regulators, media and organs in affecting the organogenesis of Alhagi. In the first step of this study, various experiments were carried out in order to optimize the callus induction and its growth. The highest rate of callus induction was achieved from the leaf segment on MS medium supplemented with 3 mg·l-1 BAP + 6 mg·l-1 NAA. Moreover, the highest rate of regeneration was recorded on MS medium supplemented with those 4 mg·l-1 BAP using for leaf segments. The optimized condition of roots induction per shoot was observed in the 1/4 MS medium without activated charcoal and supplemented with 0.25 mg·l-1 IAA. The well rooted plantlets were acclimatized and successfully established into soil where 70% plantlets were survived. The data indicate that media, BAP, and NAA levels may be manipulated to increase or decrease quality factors chosen.
基金Initial Funding of Doctor in Xinjiang University(7020428027)National Innovation Experiment Program for University Students of China (101075512)
文摘[ Objective] The aim was to establish effective method for endogenous hormone extraction and explore conditions of chromatographic analysis for three endogenous hormones in rhizome of Alhagi sparsifolia. [ Methed ] Activol （GA3 ）, zeatin （ZR） and indole-3-acetic acid （IAA） in rhizome were separated and measured as per RP-HPLC. [Result] The average recovery rates of GA3, ZR and IAA were 98.3%, 90.3% and 101.3%, respectively, indicating that the method is suitable for quantitative analysis with little errors. The chromatographic conditions were as follows： methanol/0. 75% of acetic acid at 45：55 （mobile phase） ; flow speed at 0.7 ml/min; wavelength at 254 nm; column temperature at 25 ℃. [Conclusion] The research preliminarily established HPLC conditions for separation of endogenous hormones in rhizome of Alhagi sparsifolia.
基金Supported by National Natural Science Foundation of China (Grant No. 30670386)Station Foundation of Chinese Academy of Sciences, Science and Technology Key Project of Xinjiang (Grant No. 200633130)Technology Key Project of Xinjiang (Grant No. 200733144-2)
文摘Alhagi sparsifolia is a leguminous perennial desert species that is plays an important role in dune stabilization and revegetation of degraded desert ecosystems. We investigated the effects of three different levels of salinity (50, 150, 250 mmol/L NaCl) on the growth, shoot photosynthetic parameters and salt distribution amongst different plant organs in one-year-old A. sparsifolia seedlings in a pot experiment over a 50 d period. The minimum (predawn) and maximum (midday) water potentials of A. sparsifolia seedlings decreased with the increase of external NaCl concentrations as a consequence of the osmotic or water deficit effect of saline solutions outside the roots. Salinity also reduced gas exchange parameters in A. sparsifolia, with seedlings subjected to salinity having lower photosynthesis rates and reduced stomatal conductances compared to the control. The reductions in photosynthetic rates in high salinity treatments of the A. sparsifolia seedlings were mainly caused by stomatal limitation. Consequently plants growing at greater external NaCl concentrations had significantly lower biomass accumulation compared to the control grown at 50 mmol/L. However, plants exposed to higher salinity were able to maintain growth throughout the experiment but allocated a greater proportion of biomass belowground. Plants exposed to higher external salinity levels had increased concentrations of Na+ and Cl- ions in shoots and roots, suggesting that A. sparsifolia seedlings were utilizing Na+ and Cl- as osmolytes to increase the cellular osmolality and decrease their water potential. We observed the greatest NaCl concentrations in the plants treated with 150 mmol/L NaCl indicating that there may be a threshold level of NaCl that can be tolerated by the plants. In conclusion our results indicate that A. sparsifolia seedlings are moderately salt tolerant. Photosynthetic gas exchange parameters were reduced by greater external salinity but the seedlings maintained substantial photosynthetic rates even under high salinity stress, were able to maintain growth over the 50 d experimental period and showed no signs of salinity toxicity or damage.
文摘Water relation characteristics of the desert legume Alhagi sparsifolia were investigated during the vegetation period from April to September 1999 in the foreland of Qira oasis at the southern fringe of the Taklamakan Desert, Xinjiang Uygur Autonomous Region of China. The sea- sonal variation of predawn water potentials and of diurnal water potential indicated that Alhagi plants were well water supplied over the entire vegetation period. Decreasing values in the sum- mer months were probably attributed to increasing temperatures and irradiation and therefore a higher evapotranspirative demand. Data from pressure-volume analysis confirmed that Alhagi plants were not drought stressed and xylem sap flow measurements indicated that Alhagi plants used large amounts of water during the summer months. Flood irrigation had no influence on water relations in Alhagi probably because Alhagi plants produced only few fine roots in the upper soil layers. The data indicate that Alhagi sparsifolia is a drought-avoiding species that utilizes ground water by a deep roots system, which is the key characteristic to adjust the hyper-arid environment. Because growth and survival of Alhagi depends on ground water supply, it is important that varia- tions of ground water depth are kept to a minimum. The study will provide a theoretical basis for the restoration and management of natural vegetation around oasis in arid regions.
基金Project supported by the National Natural Science Foundation of China(Nos.31370181 and 31570146)the Fujian Natural Science Funds for Distinguished Young Scholar(No.2014J06008),China
文摘We report the recovery of a 7068-nt viral sequence from the ＂viral fossils＂ embedded in the genome of Alhagi sparsifolia, a typical desert plant. Although the full viral genome remains to be completed, the putative genome structure, the deduced amino acids and phylogenetic analysis unambiguously demonstrate that this viral sequence represents a novel species of the genus Badnavirus. The putative virus is tentatively termed Alhagi bacilliform virus （ABV）. Southern blotting and inverse polymerase chain reaction （PCR） data indicate that the ABV-related sequence is integrated into the A. sparsifolia genome, and probably does not give rise to functional episomal virus. Molecular evidence that the ABV sequence exists widely in A. sparsifolia is also presented. To our knowledge, this is the first endogenous badnavirus identified from plants in the Gobi desert, and may provide new clues on the evolution, geo- graphical distribution as well as the host range of the badnaviruses.
文摘Objectives:While the protective effects of Alhagi maurorum have been shown against various ailments,its role against norfloxacin-induced adverse effects has not been studied.The current study was conducted to determine the effect of A.maurorum aqueous extract against norfloxacin-induced side effects in rats.Methods:Twenty-four male albino rats were randomly assigned into four groups,which received normal saline,norfloxacin(50 mg/kg b.wt orally once a day),A.maurorum aqueous extract(300 mg/kg b.wt orally once a day),and norfloxacin with A.maurorum aqueous extract by the same previous mentioned dosages.Blood samples were collected for hematological examination to evaluate liver and kidney function tests.Hepatic and renal tissue samples were obtained to assess antioxidant activity and histopathological examination.Results:A.maurorum aqueous extract significantly ameliorated norfloxacin-induced elevation in tissue malondialdehyde,and reduction in tissue antioxidant enzymes such as catalase,glutathione peroxidase,and superoxide dismutase activities as well as reduced glutathione concentration.Concurrent administration of A.maurorum aqueous extract with norfloxacin significantly reduced serum alkaline phosphatase,aminotransferases,urea,creatinine,and uric acid and increased RBCs count,Hb concentration,PCV,leucocyte,and monocyte counts compared with the norfloxacin-treated group.Co-administration of A.maurorum aqueous extract with norfloxacin prevented the degenerative changes induced by norfloxacin alone in liver and kidney tissues.The phytochemical profile of the extract showed the presence of carbohydrates,alkaloids,saponins,tannins,phenolics,and flavonoids.Conclusion:These findings indicated that A.maurorum possesses potent antioxidant activities and could be used to attenuate norfloxacin-induced side effects.
