Coastal wetlands face dual pressures from high salinity and heavy metal pollution,presenting significant ecological challenges.Halophytes like Sesuvium portulacastrum possess unique physiological mechanisms to mitigat...Coastal wetlands face dual pressures from high salinity and heavy metal pollution,presenting significant ecological challenges.Halophytes like Sesuvium portulacastrum possess unique physiological mechanisms to mitigate metal toxicity.This study investigates how silicon (Si) availability influences the accumulation of copper (Cu) and cadmium (Cd) in S.portulacastrum.Our results show that Si supplementation at environmentally relevant levels significantly increases Cu and Cd concentrations in the roots,while simultaneously reducing the root-to-shoot translocation of these metals.In situ non-invasive micro-testing revealed decreased metal efflux from the xylem,indicating an enhanced retention of metals in the roots.Furthermore,analyses using X-ray photoelectron spectroscopy and atomic force microscopy demonstrated a higher density of oxygen-containing functional groups and SiO-on the extracellular matrix of Si-enriched roots.This structural transformation resulted in a significant reduction in root surface potential,facilitating greater metal ion attraction and uptake.The findings from this study provide critical insights into the mechanisms by which Si availability regulates metal accumulation in halophytes,suggesting potential strategies for mitigating metal pollution in coastal wetland ecosystems.展开更多
Salt-tolerant bacteria associated with halophytes enhance plant resistance and adaptation to environmental stress.The purpose of this study was to investigate the diversity and plant-beneficial traits of bacteria asso...Salt-tolerant bacteria associated with halophytes enhance plant resistance and adaptation to environmental stress.The purpose of this study was to investigate the diversity and plant-beneficial traits of bacteria associated with three halophytes in an arid land,Northwest China.The bacterial strains were isolated from the roots,shoots,rhizosphere,and bulk soil of three halophytes,i.e.,Salicornia europaea L.,Kalidium foliatum(Pall.)Moq.,and Suaeda aralocaspica(Bunge)Freitag&Schütze,collected from the saline soils near to the Wujiaqu City,Xinjiang,Northwest China.A total of 567 strains were isolated and identified from these three halophytes belonging to 4 phyla,6 classes,25 orders,36 families,and 66 genera,including 147 potential novel species.A total of 213 strains exhibited one or more plant growthpromoting properties,while 20 strains demonstrated multiple in vitro plant growth-promoting activities,including phosphate solubilization,nitrogen fixation,siderophore production,and production of hydrolytic enzymes such as protease and cellulase.Our findings showed that halophytes in the arid land harbor diverse bacteria with the potential to enhance plant growth and adaptability under challenging environmental conditions.展开更多
Soil salinization may affect biodiversity and species composition,leading to changes in the plant community structure.However,few studies have explored the spatial pattern of soil salinization and its effects on shrub...Soil salinization may affect biodiversity and species composition,leading to changes in the plant community structure.However,few studies have explored the spatial pattern of soil salinization and its effects on shrub community structure at the ecosystem scale.Therefore,we conducted a transect sampling of desert shrublands in Northwest China during the growing season(June–September)in 2021.Soil salinization(both the degree and type),shrub community structure(e.g.,shrub density and height),and biodiversity parameters(e.g.,Simpson diversity,Margalf abundance,Shannon-Wiener diversity,and Pielou evenness indices)were used to assess the effects of soil salinization on shrub community structure.The results showed that the primary degree of soil salinization in the study area was light salinization,with the area proportion of 69.8%.Whereas the main type of soil salinization was characterized as sulfate saline soil,also accounting for 69.8%of the total area.Notably,there was a significant reduction in the degree of soil salinization and a shift in the type of soil salinization from chloride saline soil to sulfate saline soil,with an increase in longitude.Regional mean annual precipitation(MAP),mean annual evapotranspiration(MAE),elevation,and slope significantly contributed to soil salinization and its geochemical differentiation.As soil salinization intensified,shrub community structure displayed increased diversity and evenness,as indicated by the increases in the Simpson diversity,Shannon-Wiener diversity,and Pielou evenness indices.Moreover,the succulent stems and leaves of Chenopodiaceae and Tamaricaceae exhibited clear advantages under these conditions.Furthermore,regional climate and topography,such as MAP,MAE,and elevation,had greater effects on the distribution of shrub plants than soil salinization.These results provide a reference for the origin and pattern of soil salinization in drylands and their effects on the community structure of halophyte shrub species.展开更多
In the context of changes in global climate and land uses,biodiversity patterns and plant species distributions have been significantly affected.Soil salinization is a growing problem,particularly in the arid areas of...In the context of changes in global climate and land uses,biodiversity patterns and plant species distributions have been significantly affected.Soil salinization is a growing problem,particularly in the arid areas of Northwest China.Halophytes are ideal for restoring soil salinization because of their adaptability to salt stress.In this study,we collected the current and future bioclimatic data released by the WorldClim database,along with soil data from the Harmonized World Soil Database(v1.2)and A Big Earth Data Platform for Three Poles.Using the maximum entropy(MaxEnt)model,the potential suitable habitats of six halophytic plant species(Halostachys caspica(Bieb.)C.A.Mey.,Halogeton glomeratus(Bieb.)C.A.Mey.,Kalidium foliatum(Pall.)Moq.,Halocnemum strobilaceum(Pall.)Bieb.,Salicornia europaea L.,and Suaeda salsa(L.)Pall.)were assessed under the current climate conditions(average for 1970-2000)and future(2050s,2070s,and 2090s)climate scenarios(SSP245 and SSP585,where SSP is the Shared Socio-economic Pathway).The results revealed that all six halophytic plant species exhibited the area under the receiver operating characteristic curve values higher than 0.80 based on the MaxEnt model,indicating the excellent performance of the MaxEnt model.The suitability of the six halophytic plant species significantly varied across regions in the arid areas of Northwest China.Under different future climate change scenarios,the suitable habitat areas for the six halophytic plant species are expected to increase or decrease to varying degrees.As global warming progresses,the suitable habitat areas of K.foliatum,S.salsa,and H.strobilaceum exhibited an increasing trend.In contrast,the suitable habitat areas of H.glomeratus,S.europaea,and H.caspica showed an opposite trend.Furthermore,considering the ongoing global warming trend,the centroids of the suitable habitat areas for various halophytic plant species would migrate to different degrees,and four halophytic plant species,namely,S.salsa,H.strobilaceum,H.glomeratus,and H.capsica,would migrate to higher latitudes.Temperature,precipitation,and soil factors affected the possible distribution ranges of these six halophytic plant species.Among them,precipitation seasonality(coefficient of variation),precipitation of the warmest quarter,mean temperature of the warmest quarter,and exchangeable Na+significantly affected the distribution of halophytic plant species.Our findings are critical to comprehending and predicting the impact of climate change on ecosystems.The findings of this study hold significant theoretical and practical implications for the management of soil salinization and for the utilization,protection,and management of halophytes in the arid areas of Northwest China.展开更多
In this study the occurrence and ecology of plant assemblages are investigated, mainly for use as indicator plants of saline grounds in several locations in Jordan. High alkalinity and H2S-rich water tolerant species ...In this study the occurrence and ecology of plant assemblages are investigated, mainly for use as indicator plants of saline grounds in several locations in Jordan. High alkalinity and H2S-rich water tolerant species of plants are also discussed. Plants growing on salty grounds have distinct composition regarding their place in the taxonomic system. Plant assemblages and their degree of tolerance to salinity as in Karama area in the Jordan Valley are found to be distinct from that of Azraq Sabkha (Cental Jordan) with salt-tolerant flora. Karama area provides the living space for Mesembryanthemum on the saltiest ground, Suaeda further up on wetter surrounding and Salicornia succeeding on moist and less salty grounds. Drier places with rather salty grounds have bushes of Arthrocnemum, while slightly less salty places are preferred by Tamarix tetragyna. When Prosopis bushes appear, salt is only present periodically in the ground, as is also the case with Atriplex halimus and Capparis. In Azraq the former beach of a temporal lake is characterized by two species of Spergularia in its saltier parts and by Tamarix passerinoides. It was recognized that Tamarix, Phragmites, Chenopodium, and Inula represented alkaline water tolerant plants. The study concludes that the salt concentration in the ground is reflected in the composition of the flora growing on it. On the other hand, plants are also found vulnerable to fluctuation in the salt concentration of their environments with different resistance degrees. This makes them excellent bioindicators of salty environments.展开更多
Modeling soil salinity in an arid salt-affected ecosystem is a difficult task when using remote sensing data because of the complicated soil context （vegetation cover, moisture, surface roughness, and organic matter...Modeling soil salinity in an arid salt-affected ecosystem is a difficult task when using remote sensing data because of the complicated soil context （vegetation cover, moisture, surface roughness, and organic matter） and the weak spectral features of salinized soil. Therefore, an index such as the salinity index （SI） that only uses soil spectra may not detect soil salinity effectively and quantitatively. The use of vegetation reflectance as an indirect indicator can avoid limitations associated with the direct use of soil reflectance. The normalized difference vegetation index （NDVI）, as the most common vegetation index, was found to be responsive to salinity but may not be available for retrieving sparse vegetation due to its sensitivity to background soil in arid areas. Therefore, the arid fraction integrated index （AFⅡ） was created as supported by the spectral mixture analysis （SMA）, which is more appropriate for analyzing variations in vegetation cover （particularly halophytes） than NDVI in the study area. Using soil and vegetation separately for detecting salinity perhaps is not feasible. Then, we developed a new and operational model, the soil salinity detecting model （SDM） that combines AFⅡ and SI to quantitatively estimate the salt content in the surface soil. SDMs, including SDM1 and SDM2, were constructed through analyzing the spatial characteristics of soils with different salinization degree by integrating AFⅡ and SI using a scatterplot. The SDMs were then compared to the combined spectral response index （COSRI） from field measurements with respect to the soil salt content. The results indicate that the SDM values are highly correlated with soil salinity, in contrast to the performance of COSRI. Strong exponential relationships were observed between soil salinity and SDMs （R2〉0.86, RMSE〈6.86） compared to COSRI （R2=0.71, RMSE=16.21）. These results suggest that the feature space related to biophysical properties combined with AFII and SI can effectively provide information on soil salinity.展开更多
The effects of NaCl salinity and NO^-3 on growth, root morphology, and nitrogen uptake of a halophyte Suaeda physophora were evaluated in a factorial experiment with four concentrations of NaCl （1, 150, 300, and 450 ...The effects of NaCl salinity and NO^-3 on growth, root morphology, and nitrogen uptake of a halophyte Suaeda physophora were evaluated in a factorial experiment with four concentrations of NaCl （1, 150, 300, and 450 mmol L^-1） and three NO^-3 levels （0.05, 5, and 10 mmol L^-1） in solution culture for 30 d. Addition of NO^-3 at 10 mmol L^-1 significantly improved the shoot （P 〈 0.001） and root （P 〈 0.001） growth and the promotive effect of NO^-3 was more pronounced on root dry weight despite the high NaCl concentration in the culture solution, leading to a significant increase in the root：shoot ratio （P 〈 0.01）. Lateral root length, but not primary root length, considerably increased with increasing NaCl salinity and NO^-3 levels （P 〈 0.001）, implying that Na^＋ and NO3^- in the culture solution simultaneously stimulated lateral root growth. Concentrations of Na^＋ in plant tissues were also significantly increased by higher NaCl treatments （P 〈 0.001）. At 10 mmol L^-1 NO^-3, the concentrations of NO^-3 and total nitrogen and nitrate reductase activities in the roots were remarkably reduced by increasing salinity （P 〈 0.001）, but were unaffected in the shoots. The results indicated that the fine lateral root development and effective nitrogen uptake of the shoots might contribute to high salt tolerance of S. physophora under adequate NO^-3 supply.展开更多
Soil salinity is a serious environmental problem especially in arid and semiarid areas. It either occurs naturally or is human-induced. High levels of soil salinity negatively affect crop growth and productivity leadi...Soil salinity is a serious environmental problem especially in arid and semiarid areas. It either occurs naturally or is human-induced. High levels of soil salinity negatively affect crop growth and productivity leading land degradation ultimately. Thus, it is important to monitor and map soil salinity at an early stage to enact effective soil reclamation program that helps lessen or prevent future increase in soil salinity. Remote sensing has outperformed the traditional method for assessing soil salinity offering more informative and professional rapid assessment techniques for monitoring and mapping soil salinity. Soil salinity can be identified from remote sensing data obtained by different sensors by way of direct indicators that refer to salt features that are visible at the soil surface as well as indirect indicators such as the presence of halophytic plant and assessing the performance level of salt-tolerant crops. The purposes of this paper are to 1) discuss some soil salinity indicators;2) review the satellite sensors and methods used for remote monitoring, detecting and mapping of soil salinity, particularly in arid and semi-arid regions;3) review various spectral vegetation and salinity indices that have been developed and proposed for soil salinity detection and mapping, with an emphasis on soil salinity mapping and assessment in arid and semi-arid regions;and 4) highlight the most important issues limiting the use of remote sensing for soil salinity mapping, particularly in arid and semi-arid regions.展开更多
Halophytes are valuable salt-, alkali- and drought-resistant germplasm resources. However, the char- acteristics of mineral elements in halophytes have not been investigated as intensively as those in crops. This stud...Halophytes are valuable salt-, alkali- and drought-resistant germplasm resources. However, the char- acteristics of mineral elements in halophytes have not been investigated as intensively as those in crops. This study attempted to investigate the characteristics of mineral elements for annual halophytes during their growth period to reveal their possible physiological mechanisms of salt resistance. By using three native annual halophytes （Salsola subcrassa, Suaeda acuminate and Petrosimonia sibirica） distributed in the desert in Northern Xinjiang of China, the dynamic changes in the mineral element contents of annual halophytes were analyzed through field sampling and laboratory analyses. The results demonstrated that the annual halophytes were able to absorb water and mineral nutrients selectively. In the interaction between the annual halophytes and saline soil, the adaptability of the annual halophytes was manifested as the accumulation of S, Na and CI during the growth period and maintenance of water and salt balance in the plant, thus ensuring their selective absorption of N, P, K, Ca, Mg and other mineral nutrients according to their growth demand. By utilizing this property, halophyte planting and mowing （before the wilting and death periods） could bioremediate heavy saline-alkali soil.展开更多
Soil physical, chemical, and biological properties of seven desert halophytes（Kalidium foliatum, Achnatherum splendens, Leymus secalinus, Phragmites australis, Karelinia caspia, Tamarix ramosissima, Atriplex tatarica...Soil physical, chemical, and biological properties of seven desert halophytes（Kalidium foliatum, Achnatherum splendens, Leymus secalinus, Phragmites australis, Karelinia caspia, Tamarix ramosissima, Atriplex tatarica） were investigated in saline-sodic badlands of the Hexi Corridor, Gansu Province, China. The results showed that sampled soils were generally infertile and characterized by low levels of organic matter, available nitrogen, phosphorus, copper, manganese, and zinc as well as microbial communities with dominant bacteria supporting native desert halophytes. Available potassium and iron were sufficient in the study sites. With increasing soil layer depth, the concentrations of organic matter, available nitrogen, potassium, manganese, copper, bacteria, and actinomyces in the soil decreased significantly（P〈0.05）, while the concentrations of moisture, available iron, and zinc in the soil increased significantly（P〈0.05）. The contents of moisture, total salt, organic matter, available nitrogen, potassium, iron, manganese, zinc, copper, bacteria, and actinomyces showed significant seasonal variations（P〈0.05）. All these variables except bacteria and actinomyces were the greatest in summer and the lowest in spring. The redundancy analysis revealed that total salt, organic matter, available potassium, and copper were positively correlated with vegetation coverage. K. foliatum community was the constructive or dominant species in the desert community for the biological control of soil salinization.展开更多
The effects of maternal salinity and light incubation on the salinity tolerance of the facultative halophyte Anabasis setifera during their germination stages were assessed. Seeds were collected from non-saline habita...The effects of maternal salinity and light incubation on the salinity tolerance of the facultative halophyte Anabasis setifera during their germination stages were assessed. Seeds were collected from non-saline habitats in Egypt and saline habitats in the United Arab Emirates （UAE）. The seeds of the two populations were germinated in 0, 100, 200, 400, 600 and 800 mM NaCI, and incubated at 25℃/15℃ in both 12-h light and 12-h darkness regimes and continuous darkness. Significantly more seeds germinated in the Egyptian population than in the UAE population. Salinity tolerance was significantly greater with the Egyptian population than with the UAE population, especially under the conditions of higher salinities. The difference in salinity tolerance between the seeds of two populations was attributed to their seed mass. In addition, germination was significantly faster for the Egyptian population than for the UAE population. Most of the saline treated seeds were able to recover their germination when transferred to distilled water, but this depended on their maternal salinity and light incubation. Recovery from higher salinities was significantly better for the seeds under darkness than for those under light in the UAE population, but the reverse was true for the seeds in the Egyptian population. The higher salinity tolerance for the A. setifera seeds from the non-saline Egyptian population and the lower salinity tolerance for the seeds from the saline UAE population cannot explain their natural distribution. Further studies about other possible roles, such as levels of different promoting and inhibiting phytohormones, are needed to understand the importance of salinity as an environmentally induced maternal effect.展开更多
For the first time, we used Tullgren method made a study on vertical migrating and cluster analysis of the soil mesofauna in Dongying Halophytes Garden in the Yellow River Delta （YRD）, Shandong Province. The results...For the first time, we used Tullgren method made a study on vertical migrating and cluster analysis of the soil mesofauna in Dongying Halophytes Garden in the Yellow River Delta （YRD）, Shandong Province. The results showed that the soil mesofauna tended to gather on soil surface in most samples at most times, but the vertical migrating greatly varied in different seasons or environment conditions. Acari was the dominant group. The index of diversity of the soil fauna was correlated with the index of evenness. The Acari＇s number of individuals infected other species and numbers. Dominant group-Aeari made greater contribution to the result of cluster analysis, and there were significant differences between communities in different habitats by cluster analysis with both Bray-Curtis and Jaccard similarity coefficient.展开更多
The effects of various salinities and desalination on seed germination of six annual glycophytes （Artemisia sieversiana, A. scoparia, Chloris virgata, Eragrostis pilosa, Chenopodium acuminatum and Chenopodium glaucum...The effects of various salinities and desalination on seed germination of six annual glycophytes （Artemisia sieversiana, A. scoparia, Chloris virgata, Eragrostis pilosa, Chenopodium acuminatum and Chenopodium glaucum） were studied in Horqin Sandy Land, Inner Mongolia, China. NaCl solutions of five concentrations （0 mM, as the control, and 50, 100, 200 and 300 mM） were used for saline stress and desalination treatments. Increasing salinity significantly reduced germination percentages of A. sieversiana, A. scoparia, Ch.virgata and Ch. acuminatum, but had no effect on the germination percentages of E. pilosa. Lower salinity levels （50 mM） significantly increased germination percentage of Ch. glaucum. High salinity might be a precondition for germi- nation after desalination for five of the six species, excepting E. pilosa at NaCl concentration of 300 mM in comparison with non-primed seeds. Higher salinity （200 mM） led to some specific ion toxicity and reduced seed viability of A. sieversiana. No specific ion toxicity but an osmotic effect limited the germination of other five species was observed The final germination percentages （salinity stress and desalination） of the six species showed three variations in comparison with the controls, namely, indiscrimination, stimulation, and reduction. Germination responses to salinity and desalination suggested that the six species were separated into three categories. Three species （A. sieversiana, Ch. virgata and Ch. acuminatum） showed similar germination responses to salinity with those of halophyte, but also showed a lower tolerance limit than most halophytes, although this was not always the case. A. scoparia and Ch. glaucum exhibited some ‘salt stimulation’ in seed germination percentages after desalination, whereas E. pilosa did not show any obvious responseto salinity. Therefore, salinity usually induces dormancy of seeds with strong germination capacity in fresh water, but has few, or even positive, effects on seeds with strong innate dormancy.展开更多
The impacts of anthropogenisation modify permanently the distribution patterns of brackish and marine species. Globalization leads to a rapid increase of the numbers of introduced species anywhere in the world. Biolog...The impacts of anthropogenisation modify permanently the distribution patterns of brackish and marine species. Globalization leads to a rapid increase of the numbers of introduced species anywhere in the world. Biological invasions often result in significant losses in the economic value, biological diversity and function of invaded ecosystems. This review presents the main pathways of introduction of non-indigenous species and the main benthic taxonomic groups being established and/or invasive along the French Channel-Atlantic coasts. A focus is put on main invasive marine species in the intertidal and subtidal zones of Brittany (France), among macroalgae (Sargassum muticum, Grateloupia turuturu, Undaria pinnatifida, Codium fragile and Gracilaria vermiculophylla), halophytes (Spartina alterniflora) and benthic invertebrates (Mollusks: Crepidula fornicata, Crassostrea gigas and Venerupis philippinarum). The species biology, introduction vectors, reproductive and dispersal capacities are considered, together with proliferation patterns along the Channel-Atlantic coasts. The ecological impacts of these species on the environment are also described, as well as the European regulations existing to limit alien species introduction and some examples of struggle against the invaders including eradication trials and biomass valorization. Last, the on-going impacts of global changes on alien species invasiveness along the Channel-Atlantic coasts are discussed.展开更多
The lack of knowledge of plant tolerance and differential response to aluminum(Al)encouraged many researchers,in the last decade,to elucidate Al toxicity and tolerance mechanisms.The current study reported the impact ...The lack of knowledge of plant tolerance and differential response to aluminum(Al)encouraged many researchers,in the last decade,to elucidate Al toxicity and tolerance mechanisms.The current study reported the impact of Al,a toxic element with negative effects on plant growth and development,in halophytic plant Tamarix gallica.Plants were subjected to different Al concentrations(0,200,500 and 800μM)with or without NaCl(200 mM)supplementation.Growth,photosynthesis and mineral content were assessed.Al stress had a significant decrease on shoots’biomass production between 19 to 41%,and a little variation on chlorophyll content and photosynthetic efficiency(Fo,Fm,Fv fluorescence’s and Fv/Fm).Furthermore,the Al-treatments did not affect significantly the content of potassium,calcium,and magnesium in different plant parts,whereas NaCl addition to the medium induced a decrease in these elements’concentrations.Our results have shown that T.gallica is able to accumulate the high levels of Al in shoots and roots,6288μg.g^(-1) DW and 7834μg.g^(-1) DW respectively.It is considered as a hyperaccumulator plant of Al.In addition,Na+contents in shoots and roots exceed 23000μg.g^(-1) DW.Therefore,T.gallica presents a high tolerance at the same time to Al and NaCl phytotoxicity,so it is interesting to use in phytoremediation programs.展开更多
Endophytic bacteria from halophytes have a wide range of application prospects in various fields,such as plant growth-promoting,biocontrol activity and stress resistance.The current study aimed to identify cultivable ...Endophytic bacteria from halophytes have a wide range of application prospects in various fields,such as plant growth-promoting,biocontrol activity and stress resistance.The current study aimed to identify cultivable endophytic bacteria associated with halophytes grown in the salt-affected soil in Xinjiang Uygur Autonomous Region,China and to evaluate their plant beneficial traits and enzyme-producing activity.Endophytic bacteria were isolated from Reaumuria soongorica(PalL Maxim.),Artemisia carvifolia(Buch.-Ham.ex Roxb.Hort.Beng.),Peganum harmala L.and Suaeda dendroides(C.A.Mey.Moq.)by using the cultural-dependent method.Then we classified these bacteria based on the difference between their sequences of 16S rRNA(16S ribosomal RNA)gene.Results showed that the isolated bacteria from R.soongorica belonged to the genera Brucella,Bacillus and Variovorax.The bacteria from A.carvifolia belonged to the genera Micromonospora and Brucella.The bacteria from P.harmala belonged to the genera Paramesorhizobium,Bacillus and Peribacillus.The bacteria from S.dendroides belonged to the genus Bacillus.Notably,the genus Bacillus was detected in the three above plants,indicating that Bacillus is a common taxon of endophytic bacteria in halophytes.And,our results found that about 37.50%of the tested strains showed strong protease-producing activity,6.25%of the tested strains showed strong cellulase-producing activity and 12.50%of the tested strains showed moderate lipase-producing activity.Besides,all isolated strains were positive for IAA(3-Indoleacetic acid)production,31.25%of isolated strains exhibited a moderate phosphate solubilization activity and 50.00%of isolated strains exhibited a weak siderophore production activity.Our findings suggest that halophytes are valuable resources for identifying microbes with the ability to increase host plant growth and health in salt-affected soils.展开更多
Endophytic bacteria of halophytic plants play essential roles in salt stress tolerance.Therefore,an understanding of the true nature of plant-microbe interactions under extreme conditions is essential.The current stud...Endophytic bacteria of halophytic plants play essential roles in salt stress tolerance.Therefore,an understanding of the true nature of plant-microbe interactions under extreme conditions is essential.The current study aimed to identify cultivable endophytic bacteria associated with the roots and shoots of Seidlitzia rosmarinus Ehrenb.ex Boiss.grown in the salt-affected soil in Uzbekistan and to evaluate their plant beneficial traits related to plant growth stimulation and stress tolerance.Bacteria were isolated from the roots and the shoots of S.rosmarinus using culture-dependent techniques and identified by the 16S rRNA gene.RFLP(Restriction Fragment Length Polymorphism)analysis was conducted to eliminate similar isolates.Results showed that the isolates from the roots of S.rosmarinus belonged to the genera Rothia,Kocuria,Pseudomonas,Staphylococcus,Paenibacillus and Brevibacterium.The bacterial isolates from the shoots of S.rosmarinus belonged to the genera Staphylococcus,Rothia,Stenotrophomonas,Brevibacterium,Halomonas,Planococcus,Planomicrobium and Pseudomonas,which differed from those of the roots.Notably,Staphylococcus,Rothia and Brevibacterium were detected in both roots and shoots,indicating possible migration of some species from roots to shoots.The root-associated bacteria showed higher levels of IAA(indole-3-acetic acid)synthesis compared with those isolated from the shoots,as well as the higher production of ACC(1-aminocyclopropane-1-carboxylate)deaminase.Our findings suggest that halophytic plants are valuable sources for the selection of microbes with a potential to improve plant fitness under saline soils.展开更多
Objective:To evaluate the in vitro anti-Trypanosoma cruzi（T.cruzi） activity of organic extracts prepared from halophyte species collected in the southern coast of Portugal（Algarve）,and chemically characterize the ...Objective:To evaluate the in vitro anti-Trypanosoma cruzi（T.cruzi） activity of organic extracts prepared from halophyte species collected in the southern coast of Portugal（Algarve）,and chemically characterize the most active samples.Methods:Acetone,dichloromethane and methanol extracts were prepared from 31 halophyte species and tested in vitro against trypomastigotes and intracellular amastigotes of the Tulahuen strain of T.cruzi.The most active extract was fractionated by preparative HPLC-DAD,affording 11 fractions.The most selective fraction was fully characterized by 1H-NMR.Results:From 94 samples tested,one was active,namely the root dichloromethane extract of Juncus acutus(IC50 < 20 μg/mL).This extract was fractionated by HPLC,affording 11 fractions,one of them containing only a pure compound（juncunol）,and tested for anti-parasitic activity.Fraction 8(IC50 = 4.1 μg/mL) was the most active,and was further characterized by 1H-NMR.The major compounds were phenanthrenes,9,10-dihydrophenanthrenes and benzocoumarins.Conclusion:Our results suggest that the compounds identified in fraction 8 are likely responsible for the observed anti parasitic activity.Further research is in progress aiming to isolate and identify the specific active molecules.To the best of our knowledge,this is the first report on the in vitro anti T.cruzi activity of halophyte species.展开更多
基金supported by the National Natural Science Foundation of China (Nos.42376152 and 42306155)Guangdong Major Project of Basic and Applied Basic Research(No.2023B0303000017)+2 种基金the Special Program of Key Sectors in Guangdong Universities (No.2022ZDZX4040)the Innovation Team Project of Universities in Guangdong Province (No.2023KCXTD028)Guangxi Key Laboratory of Marine Environmental Change and Disaster in Beibu Gulf,Beibu Gulf University (No.2022KF007)。
文摘Coastal wetlands face dual pressures from high salinity and heavy metal pollution,presenting significant ecological challenges.Halophytes like Sesuvium portulacastrum possess unique physiological mechanisms to mitigate metal toxicity.This study investigates how silicon (Si) availability influences the accumulation of copper (Cu) and cadmium (Cd) in S.portulacastrum.Our results show that Si supplementation at environmentally relevant levels significantly increases Cu and Cd concentrations in the roots,while simultaneously reducing the root-to-shoot translocation of these metals.In situ non-invasive micro-testing revealed decreased metal efflux from the xylem,indicating an enhanced retention of metals in the roots.Furthermore,analyses using X-ray photoelectron spectroscopy and atomic force microscopy demonstrated a higher density of oxygen-containing functional groups and SiO-on the extracellular matrix of Si-enriched roots.This structural transformation resulted in a significant reduction in root surface potential,facilitating greater metal ion attraction and uptake.The findings from this study provide critical insights into the mechanisms by which Si availability regulates metal accumulation in halophytes,suggesting potential strategies for mitigating metal pollution in coastal wetland ecosystems.
基金funded by the Key Research and Development Project of Xinjiang Uygur Autonomous Region (2024B02015-3)the Regional Coordinated Innovation Project (Shanghai Cooperation Organization Science and Technology Partnership Program) of Xinjiang Uygur Autonomous Region (2025E01024)
文摘Salt-tolerant bacteria associated with halophytes enhance plant resistance and adaptation to environmental stress.The purpose of this study was to investigate the diversity and plant-beneficial traits of bacteria associated with three halophytes in an arid land,Northwest China.The bacterial strains were isolated from the roots,shoots,rhizosphere,and bulk soil of three halophytes,i.e.,Salicornia europaea L.,Kalidium foliatum(Pall.)Moq.,and Suaeda aralocaspica(Bunge)Freitag&Schütze,collected from the saline soils near to the Wujiaqu City,Xinjiang,Northwest China.A total of 567 strains were isolated and identified from these three halophytes belonging to 4 phyla,6 classes,25 orders,36 families,and 66 genera,including 147 potential novel species.A total of 213 strains exhibited one or more plant growthpromoting properties,while 20 strains demonstrated multiple in vitro plant growth-promoting activities,including phosphate solubilization,nitrogen fixation,siderophore production,and production of hydrolytic enzymes such as protease and cellulase.Our findings showed that halophytes in the arid land harbor diverse bacteria with the potential to enhance plant growth and adaptability under challenging environmental conditions.
基金financially supported by the National Natural Sciences Foundation of China(42330503,42171068)the Third Xinjiang Scientific Expedition Program(2022xjkk0901)the Tianshan Talent Training Program(2023TSYCLJ0048).
文摘Soil salinization may affect biodiversity and species composition,leading to changes in the plant community structure.However,few studies have explored the spatial pattern of soil salinization and its effects on shrub community structure at the ecosystem scale.Therefore,we conducted a transect sampling of desert shrublands in Northwest China during the growing season(June–September)in 2021.Soil salinization(both the degree and type),shrub community structure(e.g.,shrub density and height),and biodiversity parameters(e.g.,Simpson diversity,Margalf abundance,Shannon-Wiener diversity,and Pielou evenness indices)were used to assess the effects of soil salinization on shrub community structure.The results showed that the primary degree of soil salinization in the study area was light salinization,with the area proportion of 69.8%.Whereas the main type of soil salinization was characterized as sulfate saline soil,also accounting for 69.8%of the total area.Notably,there was a significant reduction in the degree of soil salinization and a shift in the type of soil salinization from chloride saline soil to sulfate saline soil,with an increase in longitude.Regional mean annual precipitation(MAP),mean annual evapotranspiration(MAE),elevation,and slope significantly contributed to soil salinization and its geochemical differentiation.As soil salinization intensified,shrub community structure displayed increased diversity and evenness,as indicated by the increases in the Simpson diversity,Shannon-Wiener diversity,and Pielou evenness indices.Moreover,the succulent stems and leaves of Chenopodiaceae and Tamaricaceae exhibited clear advantages under these conditions.Furthermore,regional climate and topography,such as MAP,MAE,and elevation,had greater effects on the distribution of shrub plants than soil salinization.These results provide a reference for the origin and pattern of soil salinization in drylands and their effects on the community structure of halophyte shrub species.
基金supported by the Third Xinjiang Scientific Expedition Program (2022xjkk1205)the Tianshan Talent Training Program (2023TSYCTD0084)+2 种基金the Science and Technology Major Program of Xinjiang Uygur Autonomous Region (2023A01002)the Young Top Talents of Xinjiang Normal University (XJNUQB2022-29)the Youth Innovation Promotion Association of the Chinese Academy of Sciences (2020437)
文摘In the context of changes in global climate and land uses,biodiversity patterns and plant species distributions have been significantly affected.Soil salinization is a growing problem,particularly in the arid areas of Northwest China.Halophytes are ideal for restoring soil salinization because of their adaptability to salt stress.In this study,we collected the current and future bioclimatic data released by the WorldClim database,along with soil data from the Harmonized World Soil Database(v1.2)and A Big Earth Data Platform for Three Poles.Using the maximum entropy(MaxEnt)model,the potential suitable habitats of six halophytic plant species(Halostachys caspica(Bieb.)C.A.Mey.,Halogeton glomeratus(Bieb.)C.A.Mey.,Kalidium foliatum(Pall.)Moq.,Halocnemum strobilaceum(Pall.)Bieb.,Salicornia europaea L.,and Suaeda salsa(L.)Pall.)were assessed under the current climate conditions(average for 1970-2000)and future(2050s,2070s,and 2090s)climate scenarios(SSP245 and SSP585,where SSP is the Shared Socio-economic Pathway).The results revealed that all six halophytic plant species exhibited the area under the receiver operating characteristic curve values higher than 0.80 based on the MaxEnt model,indicating the excellent performance of the MaxEnt model.The suitability of the six halophytic plant species significantly varied across regions in the arid areas of Northwest China.Under different future climate change scenarios,the suitable habitat areas for the six halophytic plant species are expected to increase or decrease to varying degrees.As global warming progresses,the suitable habitat areas of K.foliatum,S.salsa,and H.strobilaceum exhibited an increasing trend.In contrast,the suitable habitat areas of H.glomeratus,S.europaea,and H.caspica showed an opposite trend.Furthermore,considering the ongoing global warming trend,the centroids of the suitable habitat areas for various halophytic plant species would migrate to different degrees,and four halophytic plant species,namely,S.salsa,H.strobilaceum,H.glomeratus,and H.capsica,would migrate to higher latitudes.Temperature,precipitation,and soil factors affected the possible distribution ranges of these six halophytic plant species.Among them,precipitation seasonality(coefficient of variation),precipitation of the warmest quarter,mean temperature of the warmest quarter,and exchangeable Na+significantly affected the distribution of halophytic plant species.Our findings are critical to comprehending and predicting the impact of climate change on ecosystems.The findings of this study hold significant theoretical and practical implications for the management of soil salinization and for the utilization,protection,and management of halophytes in the arid areas of Northwest China.
文摘In this study the occurrence and ecology of plant assemblages are investigated, mainly for use as indicator plants of saline grounds in several locations in Jordan. High alkalinity and H2S-rich water tolerant species of plants are also discussed. Plants growing on salty grounds have distinct composition regarding their place in the taxonomic system. Plant assemblages and their degree of tolerance to salinity as in Karama area in the Jordan Valley are found to be distinct from that of Azraq Sabkha (Cental Jordan) with salt-tolerant flora. Karama area provides the living space for Mesembryanthemum on the saltiest ground, Suaeda further up on wetter surrounding and Salicornia succeeding on moist and less salty grounds. Drier places with rather salty grounds have bushes of Arthrocnemum, while slightly less salty places are preferred by Tamarix tetragyna. When Prosopis bushes appear, salt is only present periodically in the ground, as is also the case with Atriplex halimus and Capparis. In Azraq the former beach of a temporal lake is characterized by two species of Spergularia in its saltier parts and by Tamarix passerinoides. It was recognized that Tamarix, Phragmites, Chenopodium, and Inula represented alkaline water tolerant plants. The study concludes that the salt concentration in the ground is reflected in the composition of the flora growing on it. On the other hand, plants are also found vulnerable to fluctuation in the salt concentration of their environments with different resistance degrees. This makes them excellent bioindicators of salty environments.
基金financially supported by the National Basic Research Program of China (2009CB825105)the National Natural Science Foundation of China (41261090)
文摘Modeling soil salinity in an arid salt-affected ecosystem is a difficult task when using remote sensing data because of the complicated soil context （vegetation cover, moisture, surface roughness, and organic matter） and the weak spectral features of salinized soil. Therefore, an index such as the salinity index （SI） that only uses soil spectra may not detect soil salinity effectively and quantitatively. The use of vegetation reflectance as an indirect indicator can avoid limitations associated with the direct use of soil reflectance. The normalized difference vegetation index （NDVI）, as the most common vegetation index, was found to be responsive to salinity but may not be available for retrieving sparse vegetation due to its sensitivity to background soil in arid areas. Therefore, the arid fraction integrated index （AFⅡ） was created as supported by the spectral mixture analysis （SMA）, which is more appropriate for analyzing variations in vegetation cover （particularly halophytes） than NDVI in the study area. Using soil and vegetation separately for detecting salinity perhaps is not feasible. Then, we developed a new and operational model, the soil salinity detecting model （SDM） that combines AFⅡ and SI to quantitatively estimate the salt content in the surface soil. SDMs, including SDM1 and SDM2, were constructed through analyzing the spatial characteristics of soils with different salinization degree by integrating AFⅡ and SI using a scatterplot. The SDMs were then compared to the combined spectral response index （COSRI） from field measurements with respect to the soil salt content. The results indicate that the SDM values are highly correlated with soil salinity, in contrast to the performance of COSRI. Strong exponential relationships were observed between soil salinity and SDMs （R2〉0.86, RMSE〈6.86） compared to COSRI （R2=0.71, RMSE=16.21）. These results suggest that the feature space related to biophysical properties combined with AFII and SI can effectively provide information on soil salinity.
基金Supported by the Key Technology Program of the Xinjiang Uygur Autonomous Region, China (No.200733144-1)the Knowledge Innovation Project of the Chinese of Academy of Sciences (No.KSCX2-YW-N-41)
文摘The effects of NaCl salinity and NO^-3 on growth, root morphology, and nitrogen uptake of a halophyte Suaeda physophora were evaluated in a factorial experiment with four concentrations of NaCl （1, 150, 300, and 450 mmol L^-1） and three NO^-3 levels （0.05, 5, and 10 mmol L^-1） in solution culture for 30 d. Addition of NO^-3 at 10 mmol L^-1 significantly improved the shoot （P 〈 0.001） and root （P 〈 0.001） growth and the promotive effect of NO^-3 was more pronounced on root dry weight despite the high NaCl concentration in the culture solution, leading to a significant increase in the root：shoot ratio （P 〈 0.01）. Lateral root length, but not primary root length, considerably increased with increasing NaCl salinity and NO^-3 levels （P 〈 0.001）, implying that Na^＋ and NO3^- in the culture solution simultaneously stimulated lateral root growth. Concentrations of Na^＋ in plant tissues were also significantly increased by higher NaCl treatments （P 〈 0.001）. At 10 mmol L^-1 NO^-3, the concentrations of NO^-3 and total nitrogen and nitrate reductase activities in the roots were remarkably reduced by increasing salinity （P 〈 0.001）, but were unaffected in the shoots. The results indicated that the fine lateral root development and effective nitrogen uptake of the shoots might contribute to high salt tolerance of S. physophora under adequate NO^-3 supply.
文摘Soil salinity is a serious environmental problem especially in arid and semiarid areas. It either occurs naturally or is human-induced. High levels of soil salinity negatively affect crop growth and productivity leading land degradation ultimately. Thus, it is important to monitor and map soil salinity at an early stage to enact effective soil reclamation program that helps lessen or prevent future increase in soil salinity. Remote sensing has outperformed the traditional method for assessing soil salinity offering more informative and professional rapid assessment techniques for monitoring and mapping soil salinity. Soil salinity can be identified from remote sensing data obtained by different sensors by way of direct indicators that refer to salt features that are visible at the soil surface as well as indirect indicators such as the presence of halophytic plant and assessing the performance level of salt-tolerant crops. The purposes of this paper are to 1) discuss some soil salinity indicators;2) review the satellite sensors and methods used for remote monitoring, detecting and mapping of soil salinity, particularly in arid and semi-arid regions;3) review various spectral vegetation and salinity indices that have been developed and proposed for soil salinity detection and mapping, with an emphasis on soil salinity mapping and assessment in arid and semi-arid regions;and 4) highlight the most important issues limiting the use of remote sensing for soil salinity mapping, particularly in arid and semi-arid regions.
基金financially supported by the Scientific and Technological Project of Xinjiang Uygur Autonomous Region(201130106-2)the Innovation and Sustainable Development Research on Forest Carbon Sink in Karamay
文摘Halophytes are valuable salt-, alkali- and drought-resistant germplasm resources. However, the char- acteristics of mineral elements in halophytes have not been investigated as intensively as those in crops. This study attempted to investigate the characteristics of mineral elements for annual halophytes during their growth period to reveal their possible physiological mechanisms of salt resistance. By using three native annual halophytes （Salsola subcrassa, Suaeda acuminate and Petrosimonia sibirica） distributed in the desert in Northern Xinjiang of China, the dynamic changes in the mineral element contents of annual halophytes were analyzed through field sampling and laboratory analyses. The results demonstrated that the annual halophytes were able to absorb water and mineral nutrients selectively. In the interaction between the annual halophytes and saline soil, the adaptability of the annual halophytes was manifested as the accumulation of S, Na and CI during the growth period and maintenance of water and salt balance in the plant, thus ensuring their selective absorption of N, P, K, Ca, Mg and other mineral nutrients according to their growth demand. By utilizing this property, halophyte planting and mowing （before the wilting and death periods） could bioremediate heavy saline-alkali soil.
基金Supported by the National Natural Science Foundation of China(31460630,41163002 and 41363004)the Key Laboratory of Grassland Ecosystem of Ministry of Education(2017-D-05)
文摘Soil physical, chemical, and biological properties of seven desert halophytes（Kalidium foliatum, Achnatherum splendens, Leymus secalinus, Phragmites australis, Karelinia caspia, Tamarix ramosissima, Atriplex tatarica） were investigated in saline-sodic badlands of the Hexi Corridor, Gansu Province, China. The results showed that sampled soils were generally infertile and characterized by low levels of organic matter, available nitrogen, phosphorus, copper, manganese, and zinc as well as microbial communities with dominant bacteria supporting native desert halophytes. Available potassium and iron were sufficient in the study sites. With increasing soil layer depth, the concentrations of organic matter, available nitrogen, potassium, manganese, copper, bacteria, and actinomyces in the soil decreased significantly（P〈0.05）, while the concentrations of moisture, available iron, and zinc in the soil increased significantly（P〈0.05）. The contents of moisture, total salt, organic matter, available nitrogen, potassium, iron, manganese, zinc, copper, bacteria, and actinomyces showed significant seasonal variations（P〈0.05）. All these variables except bacteria and actinomyces were the greatest in summer and the lowest in spring. The redundancy analysis revealed that total salt, organic matter, available potassium, and copper were positively correlated with vegetation coverage. K. foliatum community was the constructive or dominant species in the desert community for the biological control of soil salinization.
基金supported by the Qatar National Research Fund(5-260-1-053)
文摘The effects of maternal salinity and light incubation on the salinity tolerance of the facultative halophyte Anabasis setifera during their germination stages were assessed. Seeds were collected from non-saline habitats in Egypt and saline habitats in the United Arab Emirates （UAE）. The seeds of the two populations were germinated in 0, 100, 200, 400, 600 and 800 mM NaCI, and incubated at 25℃/15℃ in both 12-h light and 12-h darkness regimes and continuous darkness. Significantly more seeds germinated in the Egyptian population than in the UAE population. Salinity tolerance was significantly greater with the Egyptian population than with the UAE population, especially under the conditions of higher salinities. The difference in salinity tolerance between the seeds of two populations was attributed to their seed mass. In addition, germination was significantly faster for the Egyptian population than for the UAE population. Most of the saline treated seeds were able to recover their germination when transferred to distilled water, but this depended on their maternal salinity and light incubation. Recovery from higher salinities was significantly better for the seeds under darkness than for those under light in the UAE population, but the reverse was true for the seeds in the Egyptian population. The higher salinity tolerance for the A. setifera seeds from the non-saline Egyptian population and the lower salinity tolerance for the seeds from the saline UAE population cannot explain their natural distribution. Further studies about other possible roles, such as levels of different promoting and inhibiting phytohormones, are needed to understand the importance of salinity as an environmentally induced maternal effect.
基金Supported by the Doctoral Fund of Northeast Agricultural University(2009RC41)Postdoctoral Grants of Heilongjiang Province(LBH-Z10265)
文摘For the first time, we used Tullgren method made a study on vertical migrating and cluster analysis of the soil mesofauna in Dongying Halophytes Garden in the Yellow River Delta （YRD）, Shandong Province. The results showed that the soil mesofauna tended to gather on soil surface in most samples at most times, but the vertical migrating greatly varied in different seasons or environment conditions. Acari was the dominant group. The index of diversity of the soil fauna was correlated with the index of evenness. The Acari＇s number of individuals infected other species and numbers. Dominant group-Aeari made greater contribution to the result of cluster analysis, and there were significant differences between communities in different habitats by cluster analysis with both Bray-Curtis and Jaccard similarity coefficient.
基金supported by National Nature Science Foundation of China(No.40701097,41071187)
文摘The effects of various salinities and desalination on seed germination of six annual glycophytes （Artemisia sieversiana, A. scoparia, Chloris virgata, Eragrostis pilosa, Chenopodium acuminatum and Chenopodium glaucum） were studied in Horqin Sandy Land, Inner Mongolia, China. NaCl solutions of five concentrations （0 mM, as the control, and 50, 100, 200 and 300 mM） were used for saline stress and desalination treatments. Increasing salinity significantly reduced germination percentages of A. sieversiana, A. scoparia, Ch.virgata and Ch. acuminatum, but had no effect on the germination percentages of E. pilosa. Lower salinity levels （50 mM） significantly increased germination percentage of Ch. glaucum. High salinity might be a precondition for germi- nation after desalination for five of the six species, excepting E. pilosa at NaCl concentration of 300 mM in comparison with non-primed seeds. Higher salinity （200 mM） led to some specific ion toxicity and reduced seed viability of A. sieversiana. No specific ion toxicity but an osmotic effect limited the germination of other five species was observed The final germination percentages （salinity stress and desalination） of the six species showed three variations in comparison with the controls, namely, indiscrimination, stimulation, and reduction. Germination responses to salinity and desalination suggested that the six species were separated into three categories. Three species （A. sieversiana, Ch. virgata and Ch. acuminatum） showed similar germination responses to salinity with those of halophyte, but also showed a lower tolerance limit than most halophytes, although this was not always the case. A. scoparia and Ch. glaucum exhibited some ‘salt stimulation’ in seed germination percentages after desalination, whereas E. pilosa did not show any obvious responseto salinity. Therefore, salinity usually induces dormancy of seeds with strong germination capacity in fresh water, but has few, or even positive, effects on seeds with strong innate dormancy.
文摘The impacts of anthropogenisation modify permanently the distribution patterns of brackish and marine species. Globalization leads to a rapid increase of the numbers of introduced species anywhere in the world. Biological invasions often result in significant losses in the economic value, biological diversity and function of invaded ecosystems. This review presents the main pathways of introduction of non-indigenous species and the main benthic taxonomic groups being established and/or invasive along the French Channel-Atlantic coasts. A focus is put on main invasive marine species in the intertidal and subtidal zones of Brittany (France), among macroalgae (Sargassum muticum, Grateloupia turuturu, Undaria pinnatifida, Codium fragile and Gracilaria vermiculophylla), halophytes (Spartina alterniflora) and benthic invertebrates (Mollusks: Crepidula fornicata, Crassostrea gigas and Venerupis philippinarum). The species biology, introduction vectors, reproductive and dispersal capacities are considered, together with proliferation patterns along the Channel-Atlantic coasts. The ecological impacts of these species on the environment are also described, as well as the European regulations existing to limit alien species introduction and some examples of struggle against the invaders including eradication trials and biomass valorization. Last, the on-going impacts of global changes on alien species invasiveness along the Channel-Atlantic coasts are discussed.
文摘The lack of knowledge of plant tolerance and differential response to aluminum(Al)encouraged many researchers,in the last decade,to elucidate Al toxicity and tolerance mechanisms.The current study reported the impact of Al,a toxic element with negative effects on plant growth and development,in halophytic plant Tamarix gallica.Plants were subjected to different Al concentrations(0,200,500 and 800μM)with or without NaCl(200 mM)supplementation.Growth,photosynthesis and mineral content were assessed.Al stress had a significant decrease on shoots’biomass production between 19 to 41%,and a little variation on chlorophyll content and photosynthetic efficiency(Fo,Fm,Fv fluorescence’s and Fv/Fm).Furthermore,the Al-treatments did not affect significantly the content of potassium,calcium,and magnesium in different plant parts,whereas NaCl addition to the medium induced a decrease in these elements’concentrations.Our results have shown that T.gallica is able to accumulate the high levels of Al in shoots and roots,6288μg.g^(-1) DW and 7834μg.g^(-1) DW respectively.It is considered as a hyperaccumulator plant of Al.In addition,Na+contents in shoots and roots exceed 23000μg.g^(-1) DW.Therefore,T.gallica presents a high tolerance at the same time to Al and NaCl phytotoxicity,so it is interesting to use in phytoremediation programs.
基金This research was supported by the Xinjiang Uygur Autonomous Region Regional Coordinated Innovation Project(Shanghai Cooperation Organization Science and Technology Partnership Program)(2020E01047)the National Natural Science Foundation of China(U1703106,32061143043,91751206)The authors acknowledge the anonymous reviewers for their constructive comments on the manuscript.
文摘Endophytic bacteria from halophytes have a wide range of application prospects in various fields,such as plant growth-promoting,biocontrol activity and stress resistance.The current study aimed to identify cultivable endophytic bacteria associated with halophytes grown in the salt-affected soil in Xinjiang Uygur Autonomous Region,China and to evaluate their plant beneficial traits and enzyme-producing activity.Endophytic bacteria were isolated from Reaumuria soongorica(PalL Maxim.),Artemisia carvifolia(Buch.-Ham.ex Roxb.Hort.Beng.),Peganum harmala L.and Suaeda dendroides(C.A.Mey.Moq.)by using the cultural-dependent method.Then we classified these bacteria based on the difference between their sequences of 16S rRNA(16S ribosomal RNA)gene.Results showed that the isolated bacteria from R.soongorica belonged to the genera Brucella,Bacillus and Variovorax.The bacteria from A.carvifolia belonged to the genera Micromonospora and Brucella.The bacteria from P.harmala belonged to the genera Paramesorhizobium,Bacillus and Peribacillus.The bacteria from S.dendroides belonged to the genus Bacillus.Notably,the genus Bacillus was detected in the three above plants,indicating that Bacillus is a common taxon of endophytic bacteria in halophytes.And,our results found that about 37.50%of the tested strains showed strong protease-producing activity,6.25%of the tested strains showed strong cellulase-producing activity and 12.50%of the tested strains showed moderate lipase-producing activity.Besides,all isolated strains were positive for IAA(3-Indoleacetic acid)production,31.25%of isolated strains exhibited a moderate phosphate solubilization activity and 50.00%of isolated strains exhibited a weak siderophore production activity.Our findings suggest that halophytes are valuable resources for identifying microbes with the ability to increase host plant growth and health in salt-affected soils.
基金the Eurasia Program of the Norwegian Centre for Cooperation in Education(CPEA-LT-2016/10095)the German Academic Exchange Service(DAAD)the President's International Fellowship Initiative of the Chinese Academy of Sciences(2018VBA002S).
文摘Endophytic bacteria of halophytic plants play essential roles in salt stress tolerance.Therefore,an understanding of the true nature of plant-microbe interactions under extreme conditions is essential.The current study aimed to identify cultivable endophytic bacteria associated with the roots and shoots of Seidlitzia rosmarinus Ehrenb.ex Boiss.grown in the salt-affected soil in Uzbekistan and to evaluate their plant beneficial traits related to plant growth stimulation and stress tolerance.Bacteria were isolated from the roots and the shoots of S.rosmarinus using culture-dependent techniques and identified by the 16S rRNA gene.RFLP(Restriction Fragment Length Polymorphism)analysis was conducted to eliminate similar isolates.Results showed that the isolates from the roots of S.rosmarinus belonged to the genera Rothia,Kocuria,Pseudomonas,Staphylococcus,Paenibacillus and Brevibacterium.The bacterial isolates from the shoots of S.rosmarinus belonged to the genera Staphylococcus,Rothia,Stenotrophomonas,Brevibacterium,Halomonas,Planococcus,Planomicrobium and Pseudomonas,which differed from those of the roots.Notably,Staphylococcus,Rothia and Brevibacterium were detected in both roots and shoots,indicating possible migration of some species from roots to shoots.The root-associated bacteria showed higher levels of IAA(indole-3-acetic acid)synthesis compared with those isolated from the shoots,as well as the higher production of ACC(1-aminocyclopropane-1-carboxylate)deaminase.Our findings suggest that halophytic plants are valuable sources for the selection of microbes with a potential to improve plant fitness under saline soils.
基金supported by the Xtreme Bio(PTDC/MAR-EST/4346/2012)Ma Na Cruzi projects(bilateral project,FCT/CAPES 2358,2014/2015)+3 种基金funded by FCT–Foundation for Science and Technology and Portuguese National Budgetit also received national funds through FCT project CCMAR/Multi/04326/2013 and P3DPrograma de Descoberta e Desenvolvimento de Drogas(PROEP/CNPq/FIOCRUZ 401988/2012-0)supported by FCT Investigator Programme(IF/00049/2012)Policarpo Sales by Programa Brasil Sem Miséria/Coordenacao de Aperfeicoamento de Pessoal de Ensino Superior(CAPES)/FIOCRUZ
文摘Objective:To evaluate the in vitro anti-Trypanosoma cruzi（T.cruzi） activity of organic extracts prepared from halophyte species collected in the southern coast of Portugal（Algarve）,and chemically characterize the most active samples.Methods:Acetone,dichloromethane and methanol extracts were prepared from 31 halophyte species and tested in vitro against trypomastigotes and intracellular amastigotes of the Tulahuen strain of T.cruzi.The most active extract was fractionated by preparative HPLC-DAD,affording 11 fractions.The most selective fraction was fully characterized by 1H-NMR.Results:From 94 samples tested,one was active,namely the root dichloromethane extract of Juncus acutus(IC50 < 20 μg/mL).This extract was fractionated by HPLC,affording 11 fractions,one of them containing only a pure compound（juncunol）,and tested for anti-parasitic activity.Fraction 8(IC50 = 4.1 μg/mL) was the most active,and was further characterized by 1H-NMR.The major compounds were phenanthrenes,9,10-dihydrophenanthrenes and benzocoumarins.Conclusion:Our results suggest that the compounds identified in fraction 8 are likely responsible for the observed anti parasitic activity.Further research is in progress aiming to isolate and identify the specific active molecules.To the best of our knowledge,this is the first report on the in vitro anti T.cruzi activity of halophyte species.
