[Objective] To explore a method for the rapid determination of protein con- tent in grains of Panicum miliaceum L. [Method] The near infrared transmittance spec- troscopy （NITS） was used to build the mathematical mo...[Objective] To explore a method for the rapid determination of protein con- tent in grains of Panicum miliaceum L. [Method] The near infrared transmittance spec- troscopy （NITS） was used to build the mathematical models for the quantitative analy- sis of protein content in the grains. Four combinations of treatment that first derivative and second derivative were respectively combined with partial least squares （PLS） and modified partial least squares （MPLS） were set to compare their effects on the original transmission spectrum. [Result] The predicting effects of the 4 combinations were similar. The optimal combination was first derivative with MPLS, in which the average determination coefficient of validation （RSQ） was 0.880 6, correlation coeffi- cient of cross validation （1-VR） was 0.857 0, standard error of calibration （SEC） was 0.342 4, standard error of cross validation （SECV） was 0.375 1, and the standard er- ror of prediction （SEP） was 0.454. [Conclusion] The constructed NITS model is a rapid way for the determination of protein content in grains of P. miliaceum.展开更多
To study growth responses of the roots of Panicum miliaceum L. to heterogeneous supply of nutrients. The authors analyzed the effects of the nutrient levels in both original patches (O) and destination patches (D) on ...To study growth responses of the roots of Panicum miliaceum L. to heterogeneous supply of nutrients. The authors analyzed the effects of the nutrient levels in both original patches (O) and destination patches (D) on the root growth of P. miliaceum when its roots were allowed to extend from original patch into destination patch. When the nutrient levels in the original patches were low, coarse root biomass ratio (coarse root biomass in the D/total coarse root biomass), coarse root length ratio (coarse root length in the D/total coarse root length), coarse root surface area ratio (coarse root surface area in the D/total coarse root surface area) and fine root length ratio (fine root length in the D/total fine root length) were greater in the destination patches with lower nutrient levels than in the destination patches with higher nutrient levels, while fine root length, fine root length density, fine root surface index, and fine root surface area density were smaller in the former than in the latter. When the nutrient levels in the original patches were high, fine root length, fine root length density, fine root surface area index and fine root surface density were greater in the destination patches with lower nutrient levels than in the destination patches with higher nutrient levels, coarse roots did not respond to the nutrient levels in the destination patches significantly. When the roots extended from the original patches with the same nutrient level into the destination patches with contrasting nutrient levels, fine root biomass and its percentage allocation did not respond to the nutrient levels in the destination patches significantly, whereas both root length and root surface area did. This indicates that the fine roots of P. miliaceum responded to difference in nutrient supply by plasticity in their length and surface area, rather than in their root biomass.展开更多
Heterosis plays an important role in the development of new crop varieties with high-yielding, good-quality and biotic/abiotic stresses while male sterile line de- velopment is the key step to determine the success of...Heterosis plays an important role in the development of new crop varieties with high-yielding, good-quality and biotic/abiotic stresses while male sterile line de- velopment is the key step to determine the success of heterosis utilization. A male sterile mutant, M207A was created in proso millet （Panicum mi/iaceurn, 2n=4x=36） for the first time using 60Co-y ray mutagenesis. Fertility identification and genetic analysis were carried out to characterize the mutant for its possible use for hetero- sis utilization in proso millet. First the sterility was investigated using both field sur- vey and indoor pollen microscopy identification. Then Pollinated by normal fertile proso millet cultivars, F1 and F2 populations from the mutant were obtained. Mean- while primary genetic analysis was also conducted using above populations in dif- ferent experimental sites, seasons and years. The results showed that the male sterile plant exhibited closed glumes, browning and dry anthers with few normal pollens. The sterility was stable and sterility rate was above 95% on average. The segregation ratio of fertile to sterile plants was 35：1 in the fertile selfing F2 popula- tion indicating that the mutant was a genic male sterility belonging to a pollen-less type controlled by a single recessive gene. The creation of the mutant, M207A can play a key role for heterosis utilization in proso millet.展开更多
The genetic diversity of 118 accessions of broomcom millet （Panicum miliaceum L.）, collected from various ecological areas, was analyzed. Using 46 SSR （Simple Sequence Repeat） polymorphic markers from rice, wheat,...The genetic diversity of 118 accessions of broomcom millet （Panicum miliaceum L.）, collected from various ecological areas, was analyzed. Using 46 SSR （Simple Sequence Repeat） polymorphic markers from rice, wheat, oat and barley, a total of 226 alleles were found, which exhibited moderate level of diversity. The number of alleles per primer ranged from two to nine, with an average of 4.91. The range of polymorphism information content （PIC） was 0.2844）.980 （average, 0.793）. The expected heterozygosity （He） varied from 0.346 to 0.989, with an average of 0.834. The average coefficient of the genetic similarity of SSR markers among the 118 accessions was 0.609, and it ranged from 0.461 to 0.851. The UPGMA （Unweight Pair Group Method with Arithmetic Mean） clustering analysis at the genetic similarity value of 0.609 grouped the 118 accessions into five groups. Mantel test meant that geographical origin and genetic distance presented positive correlation. The clustering results were consistent with known information on ecological growing areas. The genetic similarity coefficient of the accessions in the Loess Plateau ecotype was significantly lower than those in the other ecotypes. It indicates that the highest level of genetic diversity occurred in the Loess Plateau, which is probably the original site of Panicum miliaceum.展开更多
Biological characteristics of methane emission were compared among Oryza sativa, Panicum crus-galli andCyperus difformis grown on paddy soil. The order of the amounts of methane emitted was P. crus-galli > O. sativ...Biological characteristics of methane emission were compared among Oryza sativa, Panicum crus-galli andCyperus difformis grown on paddy soil. The order of the amounts of methane emitted was P. crus-galli > O. sativa >C. difformis, with the former two 11 and 8 times as much as that of the latter, respectively. And it was just opposite tothat of the methane-forming activities of roots of the three plants. The diurnal changes of methane emission of thethree plants were relatively consistent with valleys during 11:00-14:00 and midnight and peaks during 8:00-11: 00,14:00- 20:00 and about 5:00 early morning. The methanogenic activites in rhizospheric soils were higher than those innonrhizospheric soils with P. crus-galli and O. sativa, but not with C. difformis. The pathways of methane release ofP. crus-galli and O . sativa were probably through the top gaps near the junctions of nodal plate and leaf sheath, how-ever in C. difformistopgaps from which methane could escape into atmosphere were not found.展开更多
A novel switchgrass (Panicum virgatum) extract mediated green process was demonstrated for the synthesis of silver nanoparticles from silver nitrate solution at ambient temperature. UV-visible spectroscopic analysis i...A novel switchgrass (Panicum virgatum) extract mediated green process was demonstrated for the synthesis of silver nanoparticles from silver nitrate solution at ambient temperature. UV-visible spectroscopic analysis indicates the rapid reduction of silver (Ag+) ions by swithgrass extract. The silver nanoparticles began to form at 15 min and the reduction reaction was completed within 2 hours. Synthesized silver nanoparticles were subjected to x-ray diffraction (XRD) for structural characterization, which confirms the FCC symmetry of silver nanoparticles with the lattice parameter of 4.0962 ?. The particle size of bio-synthesized silver nanoparticles was identified through transmission electron microscopic (TEM) analysis and found to be in the range of 20 - 40 nm.展开更多
This study aims to assess the effective capacity of <i>Panicum</i><span> <i>maximum</i> </span>to accumulate cadmium (Cd), nickel (Ni) and lead (Pb). <i>P</i><span>...This study aims to assess the effective capacity of <i>Panicum</i><span> <i>maximum</i> </span>to accumulate cadmium (Cd), nickel (Ni) and lead (Pb). <i>P</i><span>. <i>maximum</i></span> observed in a greenhouse was subjected to 2 ppm of Cd, 50 ppm of Ni, 100 ppm of Pb contaminated soil and uncontaminated soil, </span></span><span><span><span style="font-family:"">for</span></span></span><span><span><span style="font-family:""> 120 days. Plant growth and biomass produced concentration of trace metals in soil and plant, bioaccumulation and transfer factors, location of potentially toxic elements in tissues and cells of plant ha</span></span></span><span><span><span style="font-family:"">ve</span></span></span><span><span><span style="font-family:""> been determined. Stem length and biomass produced by <i>P</i><span>. <i>maximum</i></span> were higher on the uncontaminated soil followed respectively by those of soil-contaminated by Pb, Cd and Ni. Bioaccumulation factors of trace metals were 8.93 (Pb), 8.47 (Ni) and 3.37 (Cd). Ni was more accumulated in shoot biomass (FT > 1), while Pb and Cd were concentrated in root biomass (FT </span></span></span><span><span><span style="font-family:""><</span></span></span><span><span><span style="font-family:""> 1). Pb is accumulated preferentially in endodermis (roots) and epidermis (leaves). As for Ni and Cd, they are concentrated in central cylinder of roots and in conductive bundles of leaves. At cellular level, Ni and Cd are mainly concentrated in intracellular compartments of leaves and roots, while Pb is strongly detected at cell walls.展开更多
Objective:To evaluate antiplasmodial and analgesic activities of ethanolic leaf extract/ fractions of Panicum maximum.Methods:The crude leaf extract(47-190 mg/kg) and fractions (chlor of orm,ethyl acqeous and methanol...Objective:To evaluate antiplasmodial and analgesic activities of ethanolic leaf extract/ fractions of Panicum maximum.Methods:The crude leaf extract(47-190 mg/kg) and fractions (chlor of orm,ethyl acqeous and methanol;96 mg/kg) of Panicum maximum were investigated for antiplasmodial activity against chloroquine sensitive Plasmodium berghei infections in mice and for analgesic activity against chemical and heat-induced pains.The antiplasmodial activity during early and established infections as well as prophylactic were investigated.Artesunate at 5 mg/kg and pyrimethamine at 1.2 mg/kg were used as positive controls.Analgesic activity of the crude extract/fractions was also evaluated against acetic acid,formalin and heat-induced pains.Results:The extract and its fractions dose-dependently reduced parasitaemia induced by chloroquine sensitive Plasmodium berghei infection in prophylactic,suppressive and curative models in mice.These reductions were statistically significant(P【0.001).They also improved the mean survival time from 13 to 28 days compared with control(P【0.001).The activities of extract/ fractions were incomparable to that of the standard drugs(Artesunate and pyrimethamine).On chemically and thermally-induced pains.the extract inhibited acetic acid and formalin-induced inflammation as well as hot plate-induced pain in mice.These inhibitions were statistically significant(P【0.001) and in a dose-dependent fashion.Condusions:Panicum maximum leaf extract has antiplasmodial and analgesic activities which may in part be mediated through the chemical constituents of the plant.展开更多
In order to investigate the differences between agronomic traits of dwarf mutant and original material 260 and whether the cause of dwarf is related to GA synthesis or signaling pathway,this experiment used dwarf muta...In order to investigate the differences between agronomic traits of dwarf mutant and original material 260 and whether the cause of dwarf is related to GA synthesis or signaling pathway,this experiment used dwarf mutant 778 and its original material 260 as experimental materials.Morphological observation and determination were performed for agronomic traits on plant height,ear length,internode length,internode number,seed length,seed width and number of seeds in different growth periods and different concentrations.The plants were treated by GA spraying,and the changes of plant height,root length,stem width,leaf length and leaf width were measured.The results are as follows:①The plant height of the dwarf mutant material was significantly different from that of the original high material,which was mainly caused by the difference between above-ground basal part and the length of the first and second elongation joints.②Comparing and analyzing the differences of traits between dwarf mutant material 778 and original high material 260,it was found that the plant height,ear length,internode number,grain number per ear and internode length of dwarf mutant 778 were significantly lower than that of high stalk 260(P<0.01),and the seed length of dwarf mutant 778 was significantly higher than that of high stalk 260(P<0.05).③Different concentrations of gibberellin(0,50,100,200 mg/L)had no significant effect on plant height and root length of dwarf mutant 778(P>0.05).Different concentrations of gibberellin had significant effects on plant height,root length and sensitivity coefficient of high stalk 260(P<0.05).And compared with the control group,all high materials 260 treated with different concentrations of gibberellin performed differently in plant morphology and growth potential.④Under the conditions of 100 and 200 mg/L GA,the difference of plant height between the dwarf mutant and the high stalk control decreased with time,and there was no difference at the end.There were no differences in sensitivity coefficient GRI between different concentrations of gibberellin treatment groups,indicating that the external gibberellin could restore the scorpion dwarf mutant to the original high stalk,and the gene that causes the mutation might be related with the gibberellin synthesis pathway.展开更多
The restoration of soils polluted by trace metals (Pb and Cd) by phytoremediation is an innovative and ecologically sustainable solution. The objective of the study was to develop a process of phytoaccumulation of tra...The restoration of soils polluted by trace metals (Pb and Cd) by phytoremediation is an innovative and ecologically sustainable solution. The objective of the study was to develop a process of phytoaccumulation of trace metals (Pb and Cd) in soils with the species Panicum maximum. For this purpose, 30 buckets containing soil were used. These included six (06) buckets per dose of soil contamination by Pb and Cd (3 mg/kg and 9 mg/kg of Cd and 100 mg/kg and 300 mg/kg of Pb) and six (6) buckets containing uncontaminated soil (control). During a period of 90 days of experimentation, the concentrations of trace metals in the plant biomass and in the soils were measured. Also, the bioaccumulation (BF) and translocation (TF) factors, the mass of Pb and Cd taken up by the plant were determined. The results showed that the biomass produced was negatively influenced by increasing Pb and Cd concentration. The concentrations of Pb and Cd accumulated by P. maximum varied in the aboveground biomass from 6.48 ± 0.55 to 18.09 ± 0.71 mg/kg (Pb100);from 10.93 ± 0.38 to 23.04 ± 0.79 mg/kg (Pb300);from 0.91 ± 0.02 to 1.50 ± 0.03 mg/kg (Cd3);and from 3.05 ± 0.08 to 5.43 ± 0.09 mg/kg (Cd9) from day 30 to day 90. However, in the root biomass, trace metals (Pb and Cd) ranged from 8.09 ± 0.58 to 22.57 ± 0.86 mg/kg (Pb100);from 29.45 ± 0.49 to 62.35 ± 0.82 mg/kg (Pb300);from 0.66 ± 0.01 to 1.11 ± 0.07 mg/kg (Cd3);and from 2.22 ± 0.08 to 3, 97 ± 0.09 mg/kg (Cd9), from day 30 to day 90. Pb was concentrated in the root biomass and Cd in the aboveground biomass. Bioaccumulation factor values ranged from 0.26 ± 0.02 to 0.99 ± 0.04 (Pb100);from 0.21 ± 0.04 to 0.50 ± 0.06 (Pb300);from 0.83 ± 0.09 to 1.72 ± 0.18 (Cd3);and from 0.70 ± 0.08 to 1.54 ± 0.18 (Cd9). High concentrations of Pb and Cd show a negative effect on the accumulation potential of P. maximum.展开更多
We attempted to introduce apomictic gene(s)into rice via somatic hybridization by usingapomictic Panicum maximum Jacq.as thedonor of apomictic gene(s).Protoplasts of rice derived from suspen-sion cells were inactivate...We attempted to introduce apomictic gene(s)into rice via somatic hybridization by usingapomictic Panicum maximum Jacq.as thedonor of apomictic gene(s).Protoplasts of rice derived from suspen-sion cells were inactivated with indoacetamide(IOA)and protoplasts of Panicum maximum展开更多
On the Kpinnou ranch in Benin,it was observed that the Girolando dairy cattle which graze Panieum maximum var.CI are more susceptible to infestation of ticks.The purpose of this study was to highlight the interactions...On the Kpinnou ranch in Benin,it was observed that the Girolando dairy cattle which graze Panieum maximum var.CI are more susceptible to infestation of ticks.The purpose of this study was to highlight the interactions between ticks and their bovine hosts and two types of artificial grazing pastures.Nineteen young Girolando dairy cattle were used during the big rainy season(March-June)2009.All present ticks on the animals have been counted according to the body region.The bovine have been divided into two relatively homogeneous groups often and nine animals.The group I of 10 animals had been grazed on Panicum maximum whereas the group 2 of 9 animals had been grazed on Panicum maximum var.C 1.During the two months of grazing,a weekly monitoring of the evolution of the load in ticks has been achieved.Four genera of ticks were identified on the bovine Girolandos(Amblyomma,Hyalomma,Rhipicephalus and Boophilus).The Boophilus genus is the most abundant(P〈0.05).The animals having grazed Panicum maximum var.C I are more infested than those that have been grazed Panicum maximum.A variation of the rate of infestation of the animals has been observed in relation to the different body areas.The colour of the coat also has an effect on the load in tick of the bovine.The bovine of dark coat are in general more infested(P〈0.05)than those of clear colour.展开更多
MicroRNAs (miRNAs) are a class of non-coding RNAs that play critical roles in post-transcriptional regulation. Their target genes are involved in a variety of biological processes such as development, metabolism, and ...MicroRNAs (miRNAs) are a class of non-coding RNAs that play critical roles in post-transcriptional regulation. Their target genes are involved in a variety of biological processes such as development, metabolism, and stress response. Panicum miliaceum L. (Panicum) is an important grain crop, but, until now, no miRNAs have been identified in this plant. Using a homology search based on expressed sequence tag (EST) analysis and miRNA precursor secondary structure, a total of 43 new miRNAs were identified. The miRNAs were found to be unevenly distributed among 11 miRNA families. Target analysis using the plant small RNA target analysis server psRNATarget showed that the newly identified miRNAs can potentially regulate 68 target genes. Ten of the 11 miRNA families were annotated as involved in RNA regulation, suggesting they may play an essential role in post-transcriptional regulation in Panicum. Selected miRNAs representing eight of the families were verified by northern blotting, indicating that the prediction method that we used to identify the miRNAs was effective.展开更多
Caffeic acid O-methyltransferase(COMT) is a crucial enzyme that mainly methylates phenylpropanoid meta-hydroxyl of C5 in the biosynthesis of syringyl lignin in angiosperms. A putative COMT, named as PvCOMT1,was isolat...Caffeic acid O-methyltransferase(COMT) is a crucial enzyme that mainly methylates phenylpropanoid meta-hydroxyl of C5 in the biosynthesis of syringyl lignin in angiosperms. A putative COMT, named as PvCOMT1,was isolated from switchgrass(Panicum virgatum), a C4 warm-season dual-purpose forage and bioenergy crop. Our results showed that recombinant PvCOMT1 enzyme protein catalyzed the methylation of 5-OH coniferyl alcohol, 5-OH coniferaldehyde(CAld5H) and 5-OH ferulic acid. Further in vitro studies indicate that CAld5H can dominate COMT-mediated reactions by inhibiting the methylation of the other substrates. Transgenic switchgrass plants generated by an RNAi approach were further employed to study the function of COMT in internode lignification. A dramatic decrease in syringyl lignin units coupled with an obvious incorporation in 5-OH guaiacyl lignin units were observed in the COMT-RNAi transgenic plants. However, the constitutive suppression of COMT in switchgrass plants altered neither the pattern of lignin deposition along the stem nor the anatomical structure of internodes. Consistent with the biochemical characterization of PvCOMT1, a significant decrease in sinapaldehyde was found in the COMT-RNAi transgenic switchgrass plants, suggesting that CAld5H could be the optimal intermediate in the biosynthesis syringyl lignin.展开更多
基金Supported by the National Key Technology R&D Program of China (2006BAD02B07)the National Mordern Agricultural Industry System of China(CARS-07-12.5-A12)~~
文摘[Objective] To explore a method for the rapid determination of protein con- tent in grains of Panicum miliaceum L. [Method] The near infrared transmittance spec- troscopy （NITS） was used to build the mathematical models for the quantitative analy- sis of protein content in the grains. Four combinations of treatment that first derivative and second derivative were respectively combined with partial least squares （PLS） and modified partial least squares （MPLS） were set to compare their effects on the original transmission spectrum. [Result] The predicting effects of the 4 combinations were similar. The optimal combination was first derivative with MPLS, in which the average determination coefficient of validation （RSQ） was 0.880 6, correlation coeffi- cient of cross validation （1-VR） was 0.857 0, standard error of calibration （SEC） was 0.342 4, standard error of cross validation （SECV） was 0.375 1, and the standard er- ror of prediction （SEP） was 0.454. [Conclusion] The constructed NITS model is a rapid way for the determination of protein content in grains of P. miliaceum.
文摘To study growth responses of the roots of Panicum miliaceum L. to heterogeneous supply of nutrients. The authors analyzed the effects of the nutrient levels in both original patches (O) and destination patches (D) on the root growth of P. miliaceum when its roots were allowed to extend from original patch into destination patch. When the nutrient levels in the original patches were low, coarse root biomass ratio (coarse root biomass in the D/total coarse root biomass), coarse root length ratio (coarse root length in the D/total coarse root length), coarse root surface area ratio (coarse root surface area in the D/total coarse root surface area) and fine root length ratio (fine root length in the D/total fine root length) were greater in the destination patches with lower nutrient levels than in the destination patches with higher nutrient levels, while fine root length, fine root length density, fine root surface index, and fine root surface area density were smaller in the former than in the latter. When the nutrient levels in the original patches were high, fine root length, fine root length density, fine root surface area index and fine root surface density were greater in the destination patches with lower nutrient levels than in the destination patches with higher nutrient levels, coarse roots did not respond to the nutrient levels in the destination patches significantly. When the roots extended from the original patches with the same nutrient level into the destination patches with contrasting nutrient levels, fine root biomass and its percentage allocation did not respond to the nutrient levels in the destination patches significantly, whereas both root length and root surface area did. This indicates that the fine roots of P. miliaceum responded to difference in nutrient supply by plasticity in their length and surface area, rather than in their root biomass.
基金Supported by the China Agricultural Research System(CARS-07-13.5-A3)the Special Financial Fund of Hebei(F16R03)~~
文摘Heterosis plays an important role in the development of new crop varieties with high-yielding, good-quality and biotic/abiotic stresses while male sterile line de- velopment is the key step to determine the success of heterosis utilization. A male sterile mutant, M207A was created in proso millet （Panicum mi/iaceurn, 2n=4x=36） for the first time using 60Co-y ray mutagenesis. Fertility identification and genetic analysis were carried out to characterize the mutant for its possible use for hetero- sis utilization in proso millet. First the sterility was investigated using both field sur- vey and indoor pollen microscopy identification. Then Pollinated by normal fertile proso millet cultivars, F1 and F2 populations from the mutant were obtained. Mean- while primary genetic analysis was also conducted using above populations in dif- ferent experimental sites, seasons and years. The results showed that the male sterile plant exhibited closed glumes, browning and dry anthers with few normal pollens. The sterility was stable and sterility rate was above 95% on average. The segregation ratio of fertile to sterile plants was 35：1 in the fertile selfing F2 popula- tion indicating that the mutant was a genic male sterility belonging to a pollen-less type controlled by a single recessive gene. The creation of the mutant, M207A can play a key role for heterosis utilization in proso millet.
基金supported by the Ministry of Science and Technology in China (No.2006BAD02B07-01)
文摘The genetic diversity of 118 accessions of broomcom millet （Panicum miliaceum L.）, collected from various ecological areas, was analyzed. Using 46 SSR （Simple Sequence Repeat） polymorphic markers from rice, wheat, oat and barley, a total of 226 alleles were found, which exhibited moderate level of diversity. The number of alleles per primer ranged from two to nine, with an average of 4.91. The range of polymorphism information content （PIC） was 0.2844）.980 （average, 0.793）. The expected heterozygosity （He） varied from 0.346 to 0.989, with an average of 0.834. The average coefficient of the genetic similarity of SSR markers among the 118 accessions was 0.609, and it ranged from 0.461 to 0.851. The UPGMA （Unweight Pair Group Method with Arithmetic Mean） clustering analysis at the genetic similarity value of 0.609 grouped the 118 accessions into five groups. Mantel test meant that geographical origin and genetic distance presented positive correlation. The clustering results were consistent with known information on ecological growing areas. The genetic similarity coefficient of the accessions in the Loess Plateau ecotype was significantly lower than those in the other ecotypes. It indicates that the highest level of genetic diversity occurred in the Loess Plateau, which is probably the original site of Panicum miliaceum.
文摘Biological characteristics of methane emission were compared among Oryza sativa, Panicum crus-galli andCyperus difformis grown on paddy soil. The order of the amounts of methane emitted was P. crus-galli > O. sativa >C. difformis, with the former two 11 and 8 times as much as that of the latter, respectively. And it was just opposite tothat of the methane-forming activities of roots of the three plants. The diurnal changes of methane emission of thethree plants were relatively consistent with valleys during 11:00-14:00 and midnight and peaks during 8:00-11: 00,14:00- 20:00 and about 5:00 early morning. The methanogenic activites in rhizospheric soils were higher than those innonrhizospheric soils with P. crus-galli and O. sativa, but not with C. difformis. The pathways of methane release ofP. crus-galli and O . sativa were probably through the top gaps near the junctions of nodal plate and leaf sheath, how-ever in C. difformistopgaps from which methane could escape into atmosphere were not found.
文摘A novel switchgrass (Panicum virgatum) extract mediated green process was demonstrated for the synthesis of silver nanoparticles from silver nitrate solution at ambient temperature. UV-visible spectroscopic analysis indicates the rapid reduction of silver (Ag+) ions by swithgrass extract. The silver nanoparticles began to form at 15 min and the reduction reaction was completed within 2 hours. Synthesized silver nanoparticles were subjected to x-ray diffraction (XRD) for structural characterization, which confirms the FCC symmetry of silver nanoparticles with the lattice parameter of 4.0962 ?. The particle size of bio-synthesized silver nanoparticles was identified through transmission electron microscopic (TEM) analysis and found to be in the range of 20 - 40 nm.
文摘This study aims to assess the effective capacity of <i>Panicum</i><span> <i>maximum</i> </span>to accumulate cadmium (Cd), nickel (Ni) and lead (Pb). <i>P</i><span>. <i>maximum</i></span> observed in a greenhouse was subjected to 2 ppm of Cd, 50 ppm of Ni, 100 ppm of Pb contaminated soil and uncontaminated soil, </span></span><span><span><span style="font-family:"">for</span></span></span><span><span><span style="font-family:""> 120 days. Plant growth and biomass produced concentration of trace metals in soil and plant, bioaccumulation and transfer factors, location of potentially toxic elements in tissues and cells of plant ha</span></span></span><span><span><span style="font-family:"">ve</span></span></span><span><span><span style="font-family:""> been determined. Stem length and biomass produced by <i>P</i><span>. <i>maximum</i></span> were higher on the uncontaminated soil followed respectively by those of soil-contaminated by Pb, Cd and Ni. Bioaccumulation factors of trace metals were 8.93 (Pb), 8.47 (Ni) and 3.37 (Cd). Ni was more accumulated in shoot biomass (FT > 1), while Pb and Cd were concentrated in root biomass (FT </span></span></span><span><span><span style="font-family:""><</span></span></span><span><span><span style="font-family:""> 1). Pb is accumulated preferentially in endodermis (roots) and epidermis (leaves). As for Ni and Cd, they are concentrated in central cylinder of roots and in conductive bundles of leaves. At cellular level, Ni and Cd are mainly concentrated in intracellular compartments of leaves and roots, while Pb is strongly detected at cell walls.
文摘Objective:To evaluate antiplasmodial and analgesic activities of ethanolic leaf extract/ fractions of Panicum maximum.Methods:The crude leaf extract(47-190 mg/kg) and fractions (chlor of orm,ethyl acqeous and methanol;96 mg/kg) of Panicum maximum were investigated for antiplasmodial activity against chloroquine sensitive Plasmodium berghei infections in mice and for analgesic activity against chemical and heat-induced pains.The antiplasmodial activity during early and established infections as well as prophylactic were investigated.Artesunate at 5 mg/kg and pyrimethamine at 1.2 mg/kg were used as positive controls.Analgesic activity of the crude extract/fractions was also evaluated against acetic acid,formalin and heat-induced pains.Results:The extract and its fractions dose-dependently reduced parasitaemia induced by chloroquine sensitive Plasmodium berghei infection in prophylactic,suppressive and curative models in mice.These reductions were statistically significant(P【0.001).They also improved the mean survival time from 13 to 28 days compared with control(P【0.001).The activities of extract/ fractions were incomparable to that of the standard drugs(Artesunate and pyrimethamine).On chemically and thermally-induced pains.the extract inhibited acetic acid and formalin-induced inflammation as well as hot plate-induced pain in mice.These inhibitions were statistically significant(P【0.001) and in a dose-dependent fashion.Condusions:Panicum maximum leaf extract has antiplasmodial and analgesic activities which may in part be mediated through the chemical constituents of the plant.
基金Supported by Project of Hebei Province Department of Science and Technology(17396310D).
文摘In order to investigate the differences between agronomic traits of dwarf mutant and original material 260 and whether the cause of dwarf is related to GA synthesis or signaling pathway,this experiment used dwarf mutant 778 and its original material 260 as experimental materials.Morphological observation and determination were performed for agronomic traits on plant height,ear length,internode length,internode number,seed length,seed width and number of seeds in different growth periods and different concentrations.The plants were treated by GA spraying,and the changes of plant height,root length,stem width,leaf length and leaf width were measured.The results are as follows:①The plant height of the dwarf mutant material was significantly different from that of the original high material,which was mainly caused by the difference between above-ground basal part and the length of the first and second elongation joints.②Comparing and analyzing the differences of traits between dwarf mutant material 778 and original high material 260,it was found that the plant height,ear length,internode number,grain number per ear and internode length of dwarf mutant 778 were significantly lower than that of high stalk 260(P<0.01),and the seed length of dwarf mutant 778 was significantly higher than that of high stalk 260(P<0.05).③Different concentrations of gibberellin(0,50,100,200 mg/L)had no significant effect on plant height and root length of dwarf mutant 778(P>0.05).Different concentrations of gibberellin had significant effects on plant height,root length and sensitivity coefficient of high stalk 260(P<0.05).And compared with the control group,all high materials 260 treated with different concentrations of gibberellin performed differently in plant morphology and growth potential.④Under the conditions of 100 and 200 mg/L GA,the difference of plant height between the dwarf mutant and the high stalk control decreased with time,and there was no difference at the end.There were no differences in sensitivity coefficient GRI between different concentrations of gibberellin treatment groups,indicating that the external gibberellin could restore the scorpion dwarf mutant to the original high stalk,and the gene that causes the mutation might be related with the gibberellin synthesis pathway.
文摘The restoration of soils polluted by trace metals (Pb and Cd) by phytoremediation is an innovative and ecologically sustainable solution. The objective of the study was to develop a process of phytoaccumulation of trace metals (Pb and Cd) in soils with the species Panicum maximum. For this purpose, 30 buckets containing soil were used. These included six (06) buckets per dose of soil contamination by Pb and Cd (3 mg/kg and 9 mg/kg of Cd and 100 mg/kg and 300 mg/kg of Pb) and six (6) buckets containing uncontaminated soil (control). During a period of 90 days of experimentation, the concentrations of trace metals in the plant biomass and in the soils were measured. Also, the bioaccumulation (BF) and translocation (TF) factors, the mass of Pb and Cd taken up by the plant were determined. The results showed that the biomass produced was negatively influenced by increasing Pb and Cd concentration. The concentrations of Pb and Cd accumulated by P. maximum varied in the aboveground biomass from 6.48 ± 0.55 to 18.09 ± 0.71 mg/kg (Pb100);from 10.93 ± 0.38 to 23.04 ± 0.79 mg/kg (Pb300);from 0.91 ± 0.02 to 1.50 ± 0.03 mg/kg (Cd3);and from 3.05 ± 0.08 to 5.43 ± 0.09 mg/kg (Cd9) from day 30 to day 90. However, in the root biomass, trace metals (Pb and Cd) ranged from 8.09 ± 0.58 to 22.57 ± 0.86 mg/kg (Pb100);from 29.45 ± 0.49 to 62.35 ± 0.82 mg/kg (Pb300);from 0.66 ± 0.01 to 1.11 ± 0.07 mg/kg (Cd3);and from 2.22 ± 0.08 to 3, 97 ± 0.09 mg/kg (Cd9), from day 30 to day 90. Pb was concentrated in the root biomass and Cd in the aboveground biomass. Bioaccumulation factor values ranged from 0.26 ± 0.02 to 0.99 ± 0.04 (Pb100);from 0.21 ± 0.04 to 0.50 ± 0.06 (Pb300);from 0.83 ± 0.09 to 1.72 ± 0.18 (Cd3);and from 0.70 ± 0.08 to 1.54 ± 0.18 (Cd9). High concentrations of Pb and Cd show a negative effect on the accumulation potential of P. maximum.
文摘We attempted to introduce apomictic gene(s)into rice via somatic hybridization by usingapomictic Panicum maximum Jacq.as thedonor of apomictic gene(s).Protoplasts of rice derived from suspen-sion cells were inactivated with indoacetamide(IOA)and protoplasts of Panicum maximum
文摘On the Kpinnou ranch in Benin,it was observed that the Girolando dairy cattle which graze Panieum maximum var.CI are more susceptible to infestation of ticks.The purpose of this study was to highlight the interactions between ticks and their bovine hosts and two types of artificial grazing pastures.Nineteen young Girolando dairy cattle were used during the big rainy season(March-June)2009.All present ticks on the animals have been counted according to the body region.The bovine have been divided into two relatively homogeneous groups often and nine animals.The group I of 10 animals had been grazed on Panicum maximum whereas the group 2 of 9 animals had been grazed on Panicum maximum var.C 1.During the two months of grazing,a weekly monitoring of the evolution of the load in ticks has been achieved.Four genera of ticks were identified on the bovine Girolandos(Amblyomma,Hyalomma,Rhipicephalus and Boophilus).The Boophilus genus is the most abundant(P〈0.05).The animals having grazed Panicum maximum var.C I are more infested than those that have been grazed Panicum maximum.A variation of the rate of infestation of the animals has been observed in relation to the different body areas.The colour of the coat also has an effect on the load in tick of the bovine.The bovine of dark coat are in general more infested(P〈0.05)than those of clear colour.
基金supported by the National Natural Science Foundation of China (Grant Nos. 30600384 and 50809068)the Young Outstanding Scholar Foundation of Northwest A & F University, China
文摘MicroRNAs (miRNAs) are a class of non-coding RNAs that play critical roles in post-transcriptional regulation. Their target genes are involved in a variety of biological processes such as development, metabolism, and stress response. Panicum miliaceum L. (Panicum) is an important grain crop, but, until now, no miRNAs have been identified in this plant. Using a homology search based on expressed sequence tag (EST) analysis and miRNA precursor secondary structure, a total of 43 new miRNAs were identified. The miRNAs were found to be unevenly distributed among 11 miRNA families. Target analysis using the plant small RNA target analysis server psRNATarget showed that the newly identified miRNAs can potentially regulate 68 target genes. Ten of the 11 miRNA families were annotated as involved in RNA regulation, suggesting they may play an essential role in post-transcriptional regulation in Panicum. Selected miRNAs representing eight of the families were verified by northern blotting, indicating that the prediction method that we used to identify the miRNAs was effective.
基金supported by the "100-Talent Program of the Chinese Academy of Sciences" foundationthe National Natural Science Foundation of China (31470390)the National Key Technologies Research & Development Program-Seven Major Crop Breeding Project (2016YFD0101803)
文摘Caffeic acid O-methyltransferase(COMT) is a crucial enzyme that mainly methylates phenylpropanoid meta-hydroxyl of C5 in the biosynthesis of syringyl lignin in angiosperms. A putative COMT, named as PvCOMT1,was isolated from switchgrass(Panicum virgatum), a C4 warm-season dual-purpose forage and bioenergy crop. Our results showed that recombinant PvCOMT1 enzyme protein catalyzed the methylation of 5-OH coniferyl alcohol, 5-OH coniferaldehyde(CAld5H) and 5-OH ferulic acid. Further in vitro studies indicate that CAld5H can dominate COMT-mediated reactions by inhibiting the methylation of the other substrates. Transgenic switchgrass plants generated by an RNAi approach were further employed to study the function of COMT in internode lignification. A dramatic decrease in syringyl lignin units coupled with an obvious incorporation in 5-OH guaiacyl lignin units were observed in the COMT-RNAi transgenic plants. However, the constitutive suppression of COMT in switchgrass plants altered neither the pattern of lignin deposition along the stem nor the anatomical structure of internodes. Consistent with the biochemical characterization of PvCOMT1, a significant decrease in sinapaldehyde was found in the COMT-RNAi transgenic switchgrass plants, suggesting that CAld5H could be the optimal intermediate in the biosynthesis syringyl lignin.
