利用新型自然光气体熏蒸平台,以23个水稻品种或株系为供试材料,设置室内对照（10.4 n L·L-1）和臭氧浓度增高（100 n L·L-1）处理,采用组内最小平方和的动态聚类方法,将供试材料按地上部最终生物量对臭氧胁迫的响应从小到大...利用新型自然光气体熏蒸平台,以23个水稻品种或株系为供试材料,设置室内对照（10.4 n L·L-1）和臭氧浓度增高（100 n L·L-1）处理,采用组内最小平方和的动态聚类方法,将供试材料按地上部最终生物量对臭氧胁迫的响应从小到大依次分为A、B和C类,研究不同敏感类型水稻营养器官中元素浓度、吸收与分配对臭氧胁迫的响应。臭氧熏蒸使A、B和C三类水稻地上部生物量平均分别下降19%、39%和52%,后两者达极显著水平。与对照相比,臭氧胁迫使稻草中N、P、K、Mg、Mn、Fe、Cu和Zn浓度显著或极显著增加（5%~42%）,但对Ca浓度没有影响。与此相反,臭氧熏蒸使稻草中所有测定元素的吸收总量均呈下降趋势,其中N、P、K、Ca、Mg、Cu、Fe和Zn吸收量的降幅均达极显著水平（11%~34%）。多数情形下,茎鞘各元素浓度和吸收量对臭氧胁迫的响应大于叶片。与此相对应,臭氧胁迫使水稻吸收的元素向叶片中分配的比例增加,而向茎鞘分配的比例减少,导致叶片与茎鞘元素吸收量的比值大幅增加（32%~92%）。臭氧与水稻类型的互作对营养器官各元素浓度以及元素在茎叶中的分配比例多无显著影响,但对元素吸收量的影响多达显著或极显著水平,后者表现为臭氧胁迫下敏感水稻元素吸收的受抑程度更大。研究结果表明,与干净空气相比,100 n L·L-1臭氧浓度对水稻营养器官中各元素浓度、吸收和分配多有显著影响,其中元素吸收量对臭氧胁迫的响应明显受水稻敏感程度的影响。展开更多
Cadmium(Cd) is highly toxic to plants, animals, and humans. Limited information is available on the role of nitric oxide(NO)and/or 24-epibrassinolide(EBR) in response of plants to Cd stress. In this study, a hydroponi...Cadmium(Cd) is highly toxic to plants, animals, and humans. Limited information is available on the role of nitric oxide(NO)and/or 24-epibrassinolide(EBR) in response of plants to Cd stress. In this study, a hydroponic experiment was performed to investigate the effects of NO and/or EBR on peanut plants subjected to Cd stress(200 μmol L^(-1)) with sodium nitroprusside(SNP, an exogenous NO donor)(250 μmol L^(-1)) and/or EBR(0.1 μmol L^(-1)) addition. The results showed that Cd exposure inhibited plant growth, and this stress was alleviated by exogenous NO or EBR, and especially the combination of the two. Treatment with Cd inhibited the growth of peanut seedlings, decreased chlorophyll content, and significantly increased the Cd concentration in plants. Furthermore, the concentration of reactive oxygen species(ROS) markedly increased in peanut seedlings under Cd stress, resulting in the accumulation of malondialdehyde(MDA) and proline in leaves and roots. Under Cd stress, applications of SNP, EBR, and especially the two in combination significantly reduced the translocation of Cd from roots to leaves, increased the chlorophyll content, decreased the concentrations of ROS, MDA, and proline, and significantly enhanced the activities of superoxide dismutase(SOD), peroxidase(POD), and catalase(CAT) in peanut seedlings. Exogenous NO and/or EBR also stimulated the activities of nitrate reductase(NR)and nitric oxide synthase(NOS) and increased the contents of antioxidants, such as ascorbic acid(AsA) and reduced glutathione(GSH). Furthermore, exogenous NO and/or EBR enhanced Cd accumulation in the cell wall and thus decreased Cd distribution in the organelles in the roots. The concentrations of calcium(Ca), iron(Fe), magnesium(Mg), and zinc(Zn) were also regulated by exogenous NO or EBR, and especially by the two in combination. These results indicated that SNP and EBR, alone and particularly in combination, can mitigate the negative effects of Cd stress in peanut plants.展开更多
The positive effects of silicon(Si) on growth of plants have been well documented;however,the impact of Si on plant nutrient uptake remains unclear.The growth,nutrient content and uptake of wheat(Triticum aestivum L.)...The positive effects of silicon(Si) on growth of plants have been well documented;however,the impact of Si on plant nutrient uptake remains unclear.The growth,nutrient content and uptake of wheat(Triticum aestivum L.),canola(Brassica napus L.) and cotton(Gossypium hirsutum L.) plants were evaluated with or without application of 1.5 mmol L^(-1) Si.Application of Si increased dry weights by 8%,30%and 30%and relative growth rate(RGR) by 10%,13%and 17%in the cotton,canola and wheat plants,respectively.The plant relative water content(RWC) was also increased,but the plant transpiration was decreased by Si application.The uptake and content of Ca^(2+) were 19%and 21%lower in the cotton and wheat plants with Si than those without Si,respectively;however,Si application increased both K^+ and Fe uptake and contents in all plant species.Silicon application reduced B uptake and content only in cotton and increased P and Zn^(2+) contents in all three plant species.The decrease in Ca^(2+) uptake by Si application was sustained even in the presence of metabolic inhibitors 2,4-dinitrophenol and sodium cyanide.Uptake of Ca^(2+) by Si application was enhanced or did not change when plant shoots were saturated with water vapor or their roots were exposed to low temperature.Thus,Si application increased the uptake of transcellularly transported elements like K^+,P,Zn^(2+) and Fe.In contrast,Ca2+ uptake which occurred via both apoplastic and transcellular pathways was decreased by Si application,possibly through reduction of apoplastic uptake.More efficient nutrient uptake might be another promoting effect of Si on plant growth.展开更多
Carex species are widely used in many parts of the world and contain a large number of ecologically diverse species.Among the Carex species,some of them are known to be glycophytes,while others are halophytes.Carex mo...Carex species are widely used in many parts of the world and contain a large number of ecologically diverse species.Among the Carex species,some of them are known to be glycophytes,while others are halophytes.Carex morrowii Boott(Cyperaceae)is resistant to trample through their root structure and has an essential ornamental value in the landscape with their leaves.However,no information was found about the level of salinity tolerance/sensitivity of the Carex morrowii among these species.In the present study,changes in trace element contents(Na,K,Ca,Cu,Mn,Mg,Ni,Fe,P,Zn,and N)and their transport from roots to leaves,osmotic regulation,alterations in chlorophyll and carotenoid contents,nitrogen assimilation(nitrate reductase activity;NRA)and total soluble protein content in both roots and leaves of Carex morrowii under different salinity concentrations(50 mM,100 mM,200 mM and 300 mM NaCl)were examined in detail.Our study provides the first detailed data concerning the responses of leaves and roots and the determination of the level of salinity tolerance/sensitivity of the Carex morrowii.The K+/Na+ratio was preserved up to 200 mM NaCl,and accordingly,the element uptake and transport ratios showed that they could control moderate NaCl levels.Ca homeostasis that is maintained even in 200 mM NaCl concentration can be effective in maintaining the structural integrity and selective permeability of the cell membranes,while 300 mM NaCl concentration caused decreased photosynthetic pigments,and deterioration in element content and compartmentation.Moreover,these data suggest that plant parts of Carex morrowii respond differently against varied levels of salinity stress.Although the decrease in NR activity at 200 mM and 300 mM NaCl concentrations in the leaves,NR activity was maintained in the roots.Consequently,Carex morrowii is moderately tolerant to salinity and the carotenoid content and osmotic regulation of Carex morrowii appears to be instrumental in its survival at different salinity levels.Especially the roots of Car展开更多
Numerous ecological factors influence a plant’s ability to live and grow,in which dryness is a substantial constraint on plant growth in arid and semi-arid areas.In response to a specific environmental stress,plants ...Numerous ecological factors influence a plant’s ability to live and grow,in which dryness is a substantial constraint on plant growth in arid and semi-arid areas.In response to a specific environmental stress,plants can use the most effective bacteria to support and facilitate their growth and development.Today,plant growth promoting rhizobacteria(PGPR)is widely used to reduce drought stress on plant growth.In this study,the effects of drought on Festuca ovina L.germination,growth,and nutrient absorption were investigated using PGPR in a factorial test with a completely random design under four water regimes.Soil water content was kept at 100%FC(field capacity),70%FC(FC),50%FC,and 30%FC.The treatments were inoculated with Azotobacter vinelandii,Pantoea agglomerans+Pseudomonas putida,and a mixture of bio-fertilizers.Results showed that the effects of drought stress were significantly reduced(P<0.05)when A.vinelandii and P.agglomerans+P.putida were used separately,however,the combined treatment of bio-fertilizers had a greater influence on seed germination than the single application.P.agglomerans+P.putida under 30%FC condition resulted in higher increases in stem,root length,and plant dry biomass.The highest uptake of nutrients was observed for the combined treatment of bio-fertilizers under 30%FC condition.Therefore,the use of A.vinelandii and P.agglomerans+P.putida,applied separately or combined,increased tolerance to drought stress in F.ovina by increased germination indices,dry weight,stem length,and root length.Because of the beneficial effects of PGPR on the growth characteristics of plants under drought conditions and the reduction of negative effects of drought stress,inoculating F.ovina seeds with Azotobacter and Pseudomonas is recommended to improve their growth and development characteristics under drought conditions.PGPR,as an affordable and environmentally friendly method,can improve the production of forage in water-stress rangelands.展开更多
文摘利用新型自然光气体熏蒸平台,以23个水稻品种或株系为供试材料,设置室内对照（10.4 n L·L-1）和臭氧浓度增高（100 n L·L-1）处理,采用组内最小平方和的动态聚类方法,将供试材料按地上部最终生物量对臭氧胁迫的响应从小到大依次分为A、B和C类,研究不同敏感类型水稻营养器官中元素浓度、吸收与分配对臭氧胁迫的响应。臭氧熏蒸使A、B和C三类水稻地上部生物量平均分别下降19%、39%和52%,后两者达极显著水平。与对照相比,臭氧胁迫使稻草中N、P、K、Mg、Mn、Fe、Cu和Zn浓度显著或极显著增加（5%~42%）,但对Ca浓度没有影响。与此相反,臭氧熏蒸使稻草中所有测定元素的吸收总量均呈下降趋势,其中N、P、K、Ca、Mg、Cu、Fe和Zn吸收量的降幅均达极显著水平（11%~34%）。多数情形下,茎鞘各元素浓度和吸收量对臭氧胁迫的响应大于叶片。与此相对应,臭氧胁迫使水稻吸收的元素向叶片中分配的比例增加,而向茎鞘分配的比例减少,导致叶片与茎鞘元素吸收量的比值大幅增加（32%~92%）。臭氧与水稻类型的互作对营养器官各元素浓度以及元素在茎叶中的分配比例多无显著影响,但对元素吸收量的影响多达显著或极显著水平,后者表现为臭氧胁迫下敏感水稻元素吸收的受抑程度更大。研究结果表明,与干净空气相比,100 n L·L-1臭氧浓度对水稻营养器官中各元素浓度、吸收和分配多有显著影响,其中元素吸收量对臭氧胁迫的响应明显受水稻敏感程度的影响。
基金supported by Shandong Provincial Natural Science Foundation (No. R2017MD010)Shandong Province Higher Educational Science and Technology Program (No. J14LF08)Taishan Scholars at Seed Industry Talent Project- Shandong Province Seed Industry Project (No. 2014),China
文摘Cadmium(Cd) is highly toxic to plants, animals, and humans. Limited information is available on the role of nitric oxide(NO)and/or 24-epibrassinolide(EBR) in response of plants to Cd stress. In this study, a hydroponic experiment was performed to investigate the effects of NO and/or EBR on peanut plants subjected to Cd stress(200 μmol L^(-1)) with sodium nitroprusside(SNP, an exogenous NO donor)(250 μmol L^(-1)) and/or EBR(0.1 μmol L^(-1)) addition. The results showed that Cd exposure inhibited plant growth, and this stress was alleviated by exogenous NO or EBR, and especially the combination of the two. Treatment with Cd inhibited the growth of peanut seedlings, decreased chlorophyll content, and significantly increased the Cd concentration in plants. Furthermore, the concentration of reactive oxygen species(ROS) markedly increased in peanut seedlings under Cd stress, resulting in the accumulation of malondialdehyde(MDA) and proline in leaves and roots. Under Cd stress, applications of SNP, EBR, and especially the two in combination significantly reduced the translocation of Cd from roots to leaves, increased the chlorophyll content, decreased the concentrations of ROS, MDA, and proline, and significantly enhanced the activities of superoxide dismutase(SOD), peroxidase(POD), and catalase(CAT) in peanut seedlings. Exogenous NO and/or EBR also stimulated the activities of nitrate reductase(NR)and nitric oxide synthase(NOS) and increased the contents of antioxidants, such as ascorbic acid(AsA) and reduced glutathione(GSH). Furthermore, exogenous NO and/or EBR enhanced Cd accumulation in the cell wall and thus decreased Cd distribution in the organelles in the roots. The concentrations of calcium(Ca), iron(Fe), magnesium(Mg), and zinc(Zn) were also regulated by exogenous NO or EBR, and especially by the two in combination. These results indicated that SNP and EBR, alone and particularly in combination, can mitigate the negative effects of Cd stress in peanut plants.
基金Golestan University Deputy of Research and Office of Higher Education,Iran,for financial support to Pooyan Mehrabanjoubani in the form of grants for Ph.D.research projects
文摘The positive effects of silicon(Si) on growth of plants have been well documented;however,the impact of Si on plant nutrient uptake remains unclear.The growth,nutrient content and uptake of wheat(Triticum aestivum L.),canola(Brassica napus L.) and cotton(Gossypium hirsutum L.) plants were evaluated with or without application of 1.5 mmol L^(-1) Si.Application of Si increased dry weights by 8%,30%and 30%and relative growth rate(RGR) by 10%,13%and 17%in the cotton,canola and wheat plants,respectively.The plant relative water content(RWC) was also increased,but the plant transpiration was decreased by Si application.The uptake and content of Ca^(2+) were 19%and 21%lower in the cotton and wheat plants with Si than those without Si,respectively;however,Si application increased both K^+ and Fe uptake and contents in all plant species.Silicon application reduced B uptake and content only in cotton and increased P and Zn^(2+) contents in all three plant species.The decrease in Ca^(2+) uptake by Si application was sustained even in the presence of metabolic inhibitors 2,4-dinitrophenol and sodium cyanide.Uptake of Ca^(2+) by Si application was enhanced or did not change when plant shoots were saturated with water vapor or their roots were exposed to low temperature.Thus,Si application increased the uptake of transcellularly transported elements like K^+,P,Zn^(2+) and Fe.In contrast,Ca2+ uptake which occurred via both apoplastic and transcellular pathways was decreased by Si application,possibly through reduction of apoplastic uptake.More efficient nutrient uptake might be another promoting effect of Si on plant growth.
文摘Carex species are widely used in many parts of the world and contain a large number of ecologically diverse species.Among the Carex species,some of them are known to be glycophytes,while others are halophytes.Carex morrowii Boott(Cyperaceae)is resistant to trample through their root structure and has an essential ornamental value in the landscape with their leaves.However,no information was found about the level of salinity tolerance/sensitivity of the Carex morrowii among these species.In the present study,changes in trace element contents(Na,K,Ca,Cu,Mn,Mg,Ni,Fe,P,Zn,and N)and their transport from roots to leaves,osmotic regulation,alterations in chlorophyll and carotenoid contents,nitrogen assimilation(nitrate reductase activity;NRA)and total soluble protein content in both roots and leaves of Carex morrowii under different salinity concentrations(50 mM,100 mM,200 mM and 300 mM NaCl)were examined in detail.Our study provides the first detailed data concerning the responses of leaves and roots and the determination of the level of salinity tolerance/sensitivity of the Carex morrowii.The K+/Na+ratio was preserved up to 200 mM NaCl,and accordingly,the element uptake and transport ratios showed that they could control moderate NaCl levels.Ca homeostasis that is maintained even in 200 mM NaCl concentration can be effective in maintaining the structural integrity and selective permeability of the cell membranes,while 300 mM NaCl concentration caused decreased photosynthetic pigments,and deterioration in element content and compartmentation.Moreover,these data suggest that plant parts of Carex morrowii respond differently against varied levels of salinity stress.Although the decrease in NR activity at 200 mM and 300 mM NaCl concentrations in the leaves,NR activity was maintained in the roots.Consequently,Carex morrowii is moderately tolerant to salinity and the carotenoid content and osmotic regulation of Carex morrowii appears to be instrumental in its survival at different salinity levels.Especially the roots of Car
基金the Research Affairs of the University of Zabol,Iran for the financial support (IRUOZ-GR-8721)。
文摘Numerous ecological factors influence a plant’s ability to live and grow,in which dryness is a substantial constraint on plant growth in arid and semi-arid areas.In response to a specific environmental stress,plants can use the most effective bacteria to support and facilitate their growth and development.Today,plant growth promoting rhizobacteria(PGPR)is widely used to reduce drought stress on plant growth.In this study,the effects of drought on Festuca ovina L.germination,growth,and nutrient absorption were investigated using PGPR in a factorial test with a completely random design under four water regimes.Soil water content was kept at 100%FC(field capacity),70%FC(FC),50%FC,and 30%FC.The treatments were inoculated with Azotobacter vinelandii,Pantoea agglomerans+Pseudomonas putida,and a mixture of bio-fertilizers.Results showed that the effects of drought stress were significantly reduced(P<0.05)when A.vinelandii and P.agglomerans+P.putida were used separately,however,the combined treatment of bio-fertilizers had a greater influence on seed germination than the single application.P.agglomerans+P.putida under 30%FC condition resulted in higher increases in stem,root length,and plant dry biomass.The highest uptake of nutrients was observed for the combined treatment of bio-fertilizers under 30%FC condition.Therefore,the use of A.vinelandii and P.agglomerans+P.putida,applied separately or combined,increased tolerance to drought stress in F.ovina by increased germination indices,dry weight,stem length,and root length.Because of the beneficial effects of PGPR on the growth characteristics of plants under drought conditions and the reduction of negative effects of drought stress,inoculating F.ovina seeds with Azotobacter and Pseudomonas is recommended to improve their growth and development characteristics under drought conditions.PGPR,as an affordable and environmentally friendly method,can improve the production of forage in water-stress rangelands.
