Intertidal macroalgae experience continual alternation of photosynthesis between aquatic state at high tide and aerial state at low tide. The comparative photosynthetic responses to inorganic carbon were investigated...Intertidal macroalgae experience continual alternation of photosynthesis between aquatic state at high tide and aerial state at low tide. The comparative photosynthetic responses to inorganic carbon were investigated in the common intertidal macroalga Ulva lactuca L. along the coast of Shantou between aquatic and aerial state. The inorganic carbon dissolved in seawater at present could fully (at 10 ℃ or 20 ℃) or nearly (at 30 ℃) saturate the aquatic photosynthesis of U. lactuca . However, the aerial photosynthesis was limited by current ambient atmospheric CO 2 level, and such a limitation was more severe at higher temperature (20-30 ℃) than at lower temperature (10 ℃). The carbon_saturated maximal photosynthesis of U. lactuca under aerial state was much greater than that under aquatic state at 10 ℃ and 20 ℃, while the maximal photosynthesis under both states was similar at 30 ℃. The aerial values of K m (CO 2) for photosynthesis were higher than the aquatic values. On the contrary, the values of apparent photosynthetic CO 2 conductance under aerial state were considerably lower than that under aquatic state. It was concluded that the increase of atmospheric CO 2 would enhance the primary productivity of U. lactuca through stimulating the photosynthesis under aerial state during low tide.展开更多
The Gross growth efficiency （GGE） is defined as the amount of consumer carbon produced relative to the amount of prey ingested in a given time interval. In population ecology, it can be considered as an index for th...The Gross growth efficiency （GGE） is defined as the amount of consumer carbon produced relative to the amount of prey ingested in a given time interval. In population ecology, it can be considered as an index for the ability of a consumer to convert the biomass of food into its population production. In this study, it was firstly applied to estimate the role of amphipods grazing in the biomass dynamics of macroalgae （Ulva lactuca） in Yundang Lagoon （a subtropical eutrophic coastal lagoon, Xiamen City, China）. It was found that amphipods were the dominant group （82.2%-98.7%） in the benthic assemblage, in which five amphipod species （Corophium uenoi, Ampithoe valida, Grandidierella japonica, Grammaropsis laevipalmata andCa-prella panantis） were observed in the lagoon. However, onlyA. valida significantly consumedU. lactuca among these amphipod species. A series of experiments were conducted to estimate the consumption of U. lactuca byA. valida. It was suggested that the monthly secondary production （P） ofA. valida using size frequency method ranged from 2.39 to 13.68 g/m2.GGEofA. valida exponentially reduced with body size and was closely associated with water temperature. Therefore,GGE equation for different months using the temperature recorded during the field investigation was fitted. The monthly consumption ofU. lactuca was figured out to be 86.7-1 549.0 g/m2 by the sum of consumption （P/GGE） byA. valida at different size, ac-counting for 2.0%-37.5% ofU. lactucaproduction. It indicates that the grazing effect ofA. valida did play a role in reducingthe accumulation ofU. lactucabiomass whenA. valida was abundant, but it finally fails to limit the U. lactucagrowth in Yundang Lagoon. Low abundance of A. valida and high nutrient loading may be two major reasons for the outbreak ofU. lactuca bloom in the lagoon.展开更多
Objective:To investigate the antioxidant and cytotoxic properties of the most active extracts from Ulva lactuca and Laurencia obtusa against colon and cervical cancer cell lines.Methods:The antioxidant radical scaveng...Objective:To investigate the antioxidant and cytotoxic properties of the most active extracts from Ulva lactuca and Laurencia obtusa against colon and cervical cancer cell lines.Methods:The antioxidant radical scavenging activity of the algal extracts was estimated using the 2,2-diphenyl-1-picrylhydrazyl colorimetric assay.Moreover,the cytotoxic potential of these bioactive extracts was studied against HCT-116 and HeLa cells by 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide assay.Wound healing analysis was adopted to evaluate the antimetastatic effects of protein extracts from both algae.Cell cycle analysis was performed by flow cytometry,and apoptotic bodies were detected using 4′,6-diamidino-2-phenylindole fluorescent staining.Amino acids of hydrolyzed protein extract were separated and identified chromatographically by high performance liquid chromatography.Results:The green algae Ulva lactuca had higher lipid content than Laurencia obtusa,whereas the latter had higher protein content with high antioxidant capacity.Protein extracts had significant dose-and time-dependent cytotoxicity and anti-metastatic activity against HCT-116 cells.Protein b extracts of both algae obtained from the chloroform:hexane solvent lipid-free residue caused morphological changes and induced apoptosis of HCT-116 cells.Further analysis revealed that apoptosis induced upon Laurencia obtusa protein b treatment was triggered via the ROS pathway,causing a significant increase in the sub-G_(1) population.Glycine and arginine(5.94 and 5.47μM,respectively)were the most common amino acids in Laurencia obtusa protein b extract.Conclusions:Proteins of Laurencia obtusa and Ulva lactuca could be considered as an adjuvant nutraceutical source of pro-apoptotic and anti-metastatic biomolecules against colon cancer.展开更多
The study aimed at evaluating the nutrient and nutraceutical potentials of the selected seaweed biomass namely Ulva lactuca and Kappaphycus alvarezii. The selected seaweeds were found to be rich in macro and micronutr...The study aimed at evaluating the nutrient and nutraceutical potentials of the selected seaweed biomass namely Ulva lactuca and Kappaphycus alvarezii. The selected seaweeds were found to be rich in macro and micronutrients. Kappaphycus contained high amount of ash when compared to U. lactuca. It is revealed that the mercury level in U. lactuca was 0.017 ppm and it was not detected in K. alvarezii. The heavy metal concentration in the selected seaweeds was within the tolerable value reported as quality criteria for edible seaweeds. These seaweeds were also found to be rich sources of vitamin antioxidants namely Vitamin C, total carotenoid, beta carotene, total chlorophyll and polyphenol. The phytochemical screening of the selected seaweeds showed that both seaweeds contained carbohydrates, protein, gums and mulicage, phenols, starch and quinones. Alkaloids was absent in Kappaphycus, saponins was moderate in U. actuca when compared to Kappaphycus. Glycosides, flavonoids, tannins and terpenoids were absent in both the species. The selected seaweeds also possess antibacterial activity. The selected biomass could be recommended for use in dietaries to combat protein energy malnutrition and in particular micronutrient deficiencies.展开更多
A deficiency in selenium(Se) in the human diet is a worldwide problem. The intake of Se-rich vegetables can be a safe way to combat Se deficiency for humans. However, most leafy vegetables can accumulate a high conten...A deficiency in selenium(Se) in the human diet is a worldwide problem. The intake of Se-rich vegetables can be a safe way to combat Se deficiency for humans. However, most leafy vegetables can accumulate a high content of nitrates, which poses a potential threat to human health. Light is an important environmental factor that regulates the uptake and distribution of mineral elements and nitrogen metabolism in plants. However, the effects of Se forms and light conditions, especially light spectra, on the uptake and translocation of Se and on nitrate reduction are poorly understood. In this study, lettuce(Lactuca sativa L.) was treated with exogenous Se applied as selenate(10 mmol L^-1) and selenite(0.5 mmol L^-1) and grown under five different light spectra: fluorescent light(FL), monochromatic red LED light(R), monochromatic blue LED light(B), and mixed red and blue LED light with a red to blue light ratio at 4(R/B=4), 8(R/B=8), and 12(R/B=12), respectively. The effects of light spectra and Se forms on plant growth, photosynthetic performance, Se accumulation and nitrate reduction were investigated. The results showed that the light spectra and Se forms had significant interactions for plant growth, foliar Se accumulation and nitrate reduction. The Se concentration and nitrate content in the leaves were negatively correlated with the percentage of red light from the light sources. Compared to Se applied as selenite, exogenous Se applied as selenate was more effective in reducing nitrate via promoting nitrate reductase and glutamate synthase activities. The lowest nitrate content and highest plant biomass were observed under R/B=8 for both the selenate and selenite treatments. The significant effect of the light spectra on the root concentration factor and translocation factor of Se resulted in marked variations in the Se concentrations in the roots and leaves. Compared with FL, red and blue LED light led to significant decreases in the foliar Se concentration. The results from this study suggest that the light spectra can contribute to Se distribution and accumulation to produce vegetables with better food quality.展开更多
Two new eudesmane sesquiterpene lactones were isolated from the stalk of Lactuca sativa vat anagustata L and their structures were elucidated by means of spectroscopic methods, including 2D NMR （1H-1H COSY, HMBC and ...Two new eudesmane sesquiterpene lactones were isolated from the stalk of Lactuca sativa vat anagustata L and their structures were elucidated by means of spectroscopic methods, including 2D NMR （1H-1H COSY, HMBC and NOESY） as 1β-O-β-D- glucopyranosyl-4α-hydroxyl-5α, 6β, 11βH-eudesma-12, 6α-olide （1） and 1β-hydroxyl-15-O-（p-methoxyphenylacetyl）-5α, 6β, 11 βH-eudesma-3-en- 12, 6a-olide （2）.展开更多
Two seed lots of lettuce (Lactuca sativa L.) cv. Krlowa Majowych were primed in polyethylene glycol (PEG) 8000 at -1.25MPa for 7 days in dark at 20C. Two fungicide treatments combined with PEG were used to control fun...Two seed lots of lettuce (Lactuca sativa L.) cv. Krlowa Majowych were primed in polyethylene glycol (PEG) 8000 at -1.25MPa for 7 days in dark at 20C. Two fungicide treatments combined with PEG were used to control fungi: 1) Funaben T(0.1%) and Apron 35 SD (0.02%) were added to -1.25 MPa PEG solution (PEG+F); 2) After seed priming and drying,Funaben T was mixed at 5 g kg-1 and Apron 35 SD at 1 g kg-1 of seeds (PEG then F dust). PEG, PEG+F and PEG then F dusttreatments reduced significantly thermodormancy and increased the seed germination at 35C in both lots. PEG then Fdust treatment had the best effect on reducing seed thermodormancy at 35C, and increased seed germination to 64.5% inlot 1 and 72.0% in lot 2 compared to 0 in untreated. PEG and PEG then F dust treatments have accelerated germinationspeed at 20 and 15C in both lots. There was a significant reduction in seed infestation in which the seeds were treatedwith PEG+F and PEG then F dust compared to untreated seeds and PEG primed seeds. PEG priming enhanced seedinfestation considerably by Alternaria alternata, Penicillium spp., Rhizopus spp. and Ulocladium spp. Mycologicalanalysis showed higher frequency of Alternaria alternata and Ulocladium spp. in untreated seeds at 20C. Priming incombination with fungicides significantly alleviated the infestation of fungi, especially Alternaria alternata infestation.展开更多
Using genomic DNA of bolting-tolerant lettuce as a template,flanking fragments of lettuce plastid rpo A gene were amplified and cloned by PCR. Targeting the sites of these two fragments,homologous recombinant fragment...Using genomic DNA of bolting-tolerant lettuce as a template,flanking fragments of lettuce plastid rpo A gene were amplified and cloned by PCR. Targeting the sites of these two fragments,homologous recombinant fragments of exogenous gene were integrated to construct lettuce plastid expression vector p Brpo AGFP,which harbored the expression cassette Prrn-gfp-aad A-Tpsb A. The results showed that the amplified flanking fragments were 1.2 and 1.1 kb in size. After sequencing,restriction digestion,ligation and transformation,lettuce plastid expression vector containing expression cassette Prrn-gfp-aad A-Tpsb A was constructed and confirmed by SDS-PAGE electrophoresis. The results of SDS-PAGE electrophoresis indicated that gfp gene was efficiently expressed under the regulation of plasmid specific promoter Prrn and terminator Tpsb A. GFP accounted for 45. 6% of total soluble proteins; inclusion bodies accounted for 47.5 % of bacterial proteins,which reached relatively high expression levels. The construction of lettuce plastid expression vector p Brpo A-GFP laid a solid foundation for establishment of subsequent lettuce plastid transformation system and genetic improvement of lettuce using various functional genes.展开更多
The effects of different concentrations of photosynthetic bacteria solutions （CK, 0 ml photosynthetic bacteria agent＋4 000 ml nutrient solution; T1, 200 ml pho- tosynthetic bacteria agent＋3 800 ml nutrient solution...The effects of different concentrations of photosynthetic bacteria solutions （CK, 0 ml photosynthetic bacteria agent＋4 000 ml nutrient solution; T1, 200 ml pho- tosynthetic bacteria agent＋3 800 ml nutrient solution; T2, 400 ml photosynthetic bacteria agent＋3 600 ml nutrient solution; T3, 600 ml photosynthetic bacteria agent＋ 3 400 ml nutrient solution; T4, 800 ml photosynthetic bacteria agent＋3 200 ml nutrient solution; and T5, 1 000 ml photosynthetic bacteria agent＋3 000 ml nutrient solu- tion） on the leaf number, fresh mass, root vigor, vitamin C content, soluble sugar content, soluble protein content and nitrate content of hydroponic Lactuca sativa L. were investigated. The results showed that the leaf number was increased by 62.66%, the fresh mass was increased by 139.7%, the root vigor was increased by 132.04%, the vitamin C content was increased by 18.34%, the soluble protein content was increased by 16.60%, the soluble sugar content was increased by 192.37%, and the nitrate content was reduced by 69.44% in the T3 group com- pared with those in the control group. The photosynthetic bacteria solution in the T3 group reduced the content of nitrate and improved the yield and quality of hydroponic L. sativa.展开更多
Pollution of the environment, particularly the soil, appears to be one of the major contemporary issues. In addition, many studies point to the involvement of ecological risk of heavy metals into the food chain throug...Pollution of the environment, particularly the soil, appears to be one of the major contemporary issues. In addition, many studies point to the involvement of ecological risk of heavy metals into the food chain through edible plants like Spinaceae oleraceae L. and Lactuca sativa L.. This paper presents the results of the ＂ex-situ＂ application of phytoacumulation on the soils of contaminated terrain using the plant species of spinach （Spinacea oleracea L.） and lettuce （Lactuca sativa L.）. Sequestration of arsen from the soil by these plant species was observed through phytoaccumulation factor--PF and limit values （mg/kg）. The main task and objective of this research was to establish the level of accumulation of toxic element As from the soil by plants and to calculate the PF factor of transfer. The experiment was set up in the control conditions where the soil from eight contaminated locations was placed in the experimental containers. The AAS method was used to analyze heavy metal in plant material and soil. PF factor values ranged from 0.1 to 1.0 which indicates that the spinach and lettuce plants rechargeable moderate compared to arsenic.展开更多
文摘Intertidal macroalgae experience continual alternation of photosynthesis between aquatic state at high tide and aerial state at low tide. The comparative photosynthetic responses to inorganic carbon were investigated in the common intertidal macroalga Ulva lactuca L. along the coast of Shantou between aquatic and aerial state. The inorganic carbon dissolved in seawater at present could fully (at 10 ℃ or 20 ℃) or nearly (at 30 ℃) saturate the aquatic photosynthesis of U. lactuca . However, the aerial photosynthesis was limited by current ambient atmospheric CO 2 level, and such a limitation was more severe at higher temperature (20-30 ℃) than at lower temperature (10 ℃). The carbon_saturated maximal photosynthesis of U. lactuca under aerial state was much greater than that under aquatic state at 10 ℃ and 20 ℃, while the maximal photosynthesis under both states was similar at 30 ℃. The aerial values of K m (CO 2) for photosynthesis were higher than the aquatic values. On the contrary, the values of apparent photosynthetic CO 2 conductance under aerial state were considerably lower than that under aquatic state. It was concluded that the increase of atmospheric CO 2 would enhance the primary productivity of U. lactuca through stimulating the photosynthesis under aerial state during low tide.
基金The Natural Science Foundation of Fujian Province under contract No.2014J01127the Public Science and Technology Research Funds Projects of Ocean under contract Nos 201205009-3 and 201105012
文摘The Gross growth efficiency （GGE） is defined as the amount of consumer carbon produced relative to the amount of prey ingested in a given time interval. In population ecology, it can be considered as an index for the ability of a consumer to convert the biomass of food into its population production. In this study, it was firstly applied to estimate the role of amphipods grazing in the biomass dynamics of macroalgae （Ulva lactuca） in Yundang Lagoon （a subtropical eutrophic coastal lagoon, Xiamen City, China）. It was found that amphipods were the dominant group （82.2%-98.7%） in the benthic assemblage, in which five amphipod species （Corophium uenoi, Ampithoe valida, Grandidierella japonica, Grammaropsis laevipalmata andCa-prella panantis） were observed in the lagoon. However, onlyA. valida significantly consumedU. lactuca among these amphipod species. A series of experiments were conducted to estimate the consumption of U. lactuca byA. valida. It was suggested that the monthly secondary production （P） ofA. valida using size frequency method ranged from 2.39 to 13.68 g/m2.GGEofA. valida exponentially reduced with body size and was closely associated with water temperature. Therefore,GGE equation for different months using the temperature recorded during the field investigation was fitted. The monthly consumption ofU. lactuca was figured out to be 86.7-1 549.0 g/m2 by the sum of consumption （P/GGE） byA. valida at different size, ac-counting for 2.0%-37.5% ofU. lactucaproduction. It indicates that the grazing effect ofA. valida did play a role in reducingthe accumulation ofU. lactucabiomass whenA. valida was abundant, but it finally fails to limit the U. lactucagrowth in Yundang Lagoon. Low abundance of A. valida and high nutrient loading may be two major reasons for the outbreak ofU. lactuca bloom in the lagoon.
文摘Objective:To investigate the antioxidant and cytotoxic properties of the most active extracts from Ulva lactuca and Laurencia obtusa against colon and cervical cancer cell lines.Methods:The antioxidant radical scavenging activity of the algal extracts was estimated using the 2,2-diphenyl-1-picrylhydrazyl colorimetric assay.Moreover,the cytotoxic potential of these bioactive extracts was studied against HCT-116 and HeLa cells by 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide assay.Wound healing analysis was adopted to evaluate the antimetastatic effects of protein extracts from both algae.Cell cycle analysis was performed by flow cytometry,and apoptotic bodies were detected using 4′,6-diamidino-2-phenylindole fluorescent staining.Amino acids of hydrolyzed protein extract were separated and identified chromatographically by high performance liquid chromatography.Results:The green algae Ulva lactuca had higher lipid content than Laurencia obtusa,whereas the latter had higher protein content with high antioxidant capacity.Protein extracts had significant dose-and time-dependent cytotoxicity and anti-metastatic activity against HCT-116 cells.Protein b extracts of both algae obtained from the chloroform:hexane solvent lipid-free residue caused morphological changes and induced apoptosis of HCT-116 cells.Further analysis revealed that apoptosis induced upon Laurencia obtusa protein b treatment was triggered via the ROS pathway,causing a significant increase in the sub-G_(1) population.Glycine and arginine(5.94 and 5.47μM,respectively)were the most common amino acids in Laurencia obtusa protein b extract.Conclusions:Proteins of Laurencia obtusa and Ulva lactuca could be considered as an adjuvant nutraceutical source of pro-apoptotic and anti-metastatic biomolecules against colon cancer.
文摘The study aimed at evaluating the nutrient and nutraceutical potentials of the selected seaweed biomass namely Ulva lactuca and Kappaphycus alvarezii. The selected seaweeds were found to be rich in macro and micronutrients. Kappaphycus contained high amount of ash when compared to U. lactuca. It is revealed that the mercury level in U. lactuca was 0.017 ppm and it was not detected in K. alvarezii. The heavy metal concentration in the selected seaweeds was within the tolerable value reported as quality criteria for edible seaweeds. These seaweeds were also found to be rich sources of vitamin antioxidants namely Vitamin C, total carotenoid, beta carotene, total chlorophyll and polyphenol. The phytochemical screening of the selected seaweeds showed that both seaweeds contained carbohydrates, protein, gums and mulicage, phenols, starch and quinones. Alkaloids was absent in Kappaphycus, saponins was moderate in U. actuca when compared to Kappaphycus. Glycosides, flavonoids, tannins and terpenoids were absent in both the species. The selected seaweeds also possess antibacterial activity. The selected biomass could be recommended for use in dietaries to combat protein energy malnutrition and in particular micronutrient deficiencies.
基金financially supported by the Central Public Interest Science Institute Basal Research Fund (Y2019xk21-01)the Nottingham Trent University Q&R Fund, UK (01ARE RA 926)the Key Projects of Ningxia Key R&D Program Fund, China (2018BBF02012)
文摘A deficiency in selenium(Se) in the human diet is a worldwide problem. The intake of Se-rich vegetables can be a safe way to combat Se deficiency for humans. However, most leafy vegetables can accumulate a high content of nitrates, which poses a potential threat to human health. Light is an important environmental factor that regulates the uptake and distribution of mineral elements and nitrogen metabolism in plants. However, the effects of Se forms and light conditions, especially light spectra, on the uptake and translocation of Se and on nitrate reduction are poorly understood. In this study, lettuce(Lactuca sativa L.) was treated with exogenous Se applied as selenate(10 mmol L^-1) and selenite(0.5 mmol L^-1) and grown under five different light spectra: fluorescent light(FL), monochromatic red LED light(R), monochromatic blue LED light(B), and mixed red and blue LED light with a red to blue light ratio at 4(R/B=4), 8(R/B=8), and 12(R/B=12), respectively. The effects of light spectra and Se forms on plant growth, photosynthetic performance, Se accumulation and nitrate reduction were investigated. The results showed that the light spectra and Se forms had significant interactions for plant growth, foliar Se accumulation and nitrate reduction. The Se concentration and nitrate content in the leaves were negatively correlated with the percentage of red light from the light sources. Compared to Se applied as selenite, exogenous Se applied as selenate was more effective in reducing nitrate via promoting nitrate reductase and glutamate synthase activities. The lowest nitrate content and highest plant biomass were observed under R/B=8 for both the selenate and selenite treatments. The significant effect of the light spectra on the root concentration factor and translocation factor of Se resulted in marked variations in the Se concentrations in the roots and leaves. Compared with FL, red and blue LED light led to significant decreases in the foliar Se concentration. The results from this study suggest that the light spectra can contribute to Se distribution and accumulation to produce vegetables with better food quality.
基金financed by the Science Foundation of Zhejiang Sci-Tech University(No.0613266-Y)the Talents Training Foundation of Key Laboratory of Advanced Textile Materials and Manufacturing Technology (Zhejiang Sci-Tech University),Ministry of Education(No.2006QN04)
文摘Two new eudesmane sesquiterpene lactones were isolated from the stalk of Lactuca sativa vat anagustata L and their structures were elucidated by means of spectroscopic methods, including 2D NMR （1H-1H COSY, HMBC and NOESY） as 1β-O-β-D- glucopyranosyl-4α-hydroxyl-5α, 6β, 11βH-eudesma-12, 6α-olide （1） and 1β-hydroxyl-15-O-（p-methoxyphenylacetyl）-5α, 6β, 11 βH-eudesma-3-en- 12, 6a-olide （2）.
基金supported by Cooperation Project between China and Poland Government of Ministry of Science and Technology of China(AM30:001(30-20))the National Natural Science Foundation of China(30370911).
文摘Two seed lots of lettuce (Lactuca sativa L.) cv. Krlowa Majowych were primed in polyethylene glycol (PEG) 8000 at -1.25MPa for 7 days in dark at 20C. Two fungicide treatments combined with PEG were used to control fungi: 1) Funaben T(0.1%) and Apron 35 SD (0.02%) were added to -1.25 MPa PEG solution (PEG+F); 2) After seed priming and drying,Funaben T was mixed at 5 g kg-1 and Apron 35 SD at 1 g kg-1 of seeds (PEG then F dust). PEG, PEG+F and PEG then F dusttreatments reduced significantly thermodormancy and increased the seed germination at 35C in both lots. PEG then Fdust treatment had the best effect on reducing seed thermodormancy at 35C, and increased seed germination to 64.5% inlot 1 and 72.0% in lot 2 compared to 0 in untreated. PEG and PEG then F dust treatments have accelerated germinationspeed at 20 and 15C in both lots. There was a significant reduction in seed infestation in which the seeds were treatedwith PEG+F and PEG then F dust compared to untreated seeds and PEG primed seeds. PEG priming enhanced seedinfestation considerably by Alternaria alternata, Penicillium spp., Rhizopus spp. and Ulocladium spp. Mycologicalanalysis showed higher frequency of Alternaria alternata and Ulocladium spp. in untreated seeds at 20C. Priming incombination with fungicides significantly alleviated the infestation of fungi, especially Alternaria alternata infestation.
基金Supported by Natural Science Foundation of Yunnan Province(2011FB049)National Natural Science Foundation of China(31260481,31460516)+2 种基金Fund of Yunnan Education Department(2013Y251)Fund of the Department of Life Science and Technology,Kunming University(GXKM201505)Talent Fund for PhD(YJL11015)
文摘Using genomic DNA of bolting-tolerant lettuce as a template,flanking fragments of lettuce plastid rpo A gene were amplified and cloned by PCR. Targeting the sites of these two fragments,homologous recombinant fragments of exogenous gene were integrated to construct lettuce plastid expression vector p Brpo AGFP,which harbored the expression cassette Prrn-gfp-aad A-Tpsb A. The results showed that the amplified flanking fragments were 1.2 and 1.1 kb in size. After sequencing,restriction digestion,ligation and transformation,lettuce plastid expression vector containing expression cassette Prrn-gfp-aad A-Tpsb A was constructed and confirmed by SDS-PAGE electrophoresis. The results of SDS-PAGE electrophoresis indicated that gfp gene was efficiently expressed under the regulation of plasmid specific promoter Prrn and terminator Tpsb A. GFP accounted for 45. 6% of total soluble proteins; inclusion bodies accounted for 47.5 % of bacterial proteins,which reached relatively high expression levels. The construction of lettuce plastid expression vector p Brpo A-GFP laid a solid foundation for establishment of subsequent lettuce plastid transformation system and genetic improvement of lettuce using various functional genes.
文摘The effects of different concentrations of photosynthetic bacteria solutions （CK, 0 ml photosynthetic bacteria agent＋4 000 ml nutrient solution; T1, 200 ml pho- tosynthetic bacteria agent＋3 800 ml nutrient solution; T2, 400 ml photosynthetic bacteria agent＋3 600 ml nutrient solution; T3, 600 ml photosynthetic bacteria agent＋ 3 400 ml nutrient solution; T4, 800 ml photosynthetic bacteria agent＋3 200 ml nutrient solution; and T5, 1 000 ml photosynthetic bacteria agent＋3 000 ml nutrient solu- tion） on the leaf number, fresh mass, root vigor, vitamin C content, soluble sugar content, soluble protein content and nitrate content of hydroponic Lactuca sativa L. were investigated. The results showed that the leaf number was increased by 62.66%, the fresh mass was increased by 139.7%, the root vigor was increased by 132.04%, the vitamin C content was increased by 18.34%, the soluble protein content was increased by 16.60%, the soluble sugar content was increased by 192.37%, and the nitrate content was reduced by 69.44% in the T3 group com- pared with those in the control group. The photosynthetic bacteria solution in the T3 group reduced the content of nitrate and improved the yield and quality of hydroponic L. sativa.
文摘Pollution of the environment, particularly the soil, appears to be one of the major contemporary issues. In addition, many studies point to the involvement of ecological risk of heavy metals into the food chain through edible plants like Spinaceae oleraceae L. and Lactuca sativa L.. This paper presents the results of the ＂ex-situ＂ application of phytoacumulation on the soils of contaminated terrain using the plant species of spinach （Spinacea oleracea L.） and lettuce （Lactuca sativa L.）. Sequestration of arsen from the soil by these plant species was observed through phytoaccumulation factor--PF and limit values （mg/kg）. The main task and objective of this research was to establish the level of accumulation of toxic element As from the soil by plants and to calculate the PF factor of transfer. The experiment was set up in the control conditions where the soil from eight contaminated locations was placed in the experimental containers. The AAS method was used to analyze heavy metal in plant material and soil. PF factor values ranged from 0.1 to 1.0 which indicates that the spinach and lettuce plants rechargeable moderate compared to arsenic.
