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Antitumor mechanism of Se-containing polysaccharide, a novel organic selenium compound
Dejing SHANG, Qiao CUI, Yang LI, Zhi YU, Lei WEN, Yuan ZHAO, Jianing ZHANG
Front Biol Chin. 2009, 4 (3): 248-253.
https://doi.org/10.1007/s11515-009-0020-y
Recent studies on the inhibition of tumor growth by Se-containing polysaccharide were reviewed. Meanwhile, the possible molecular mechanisms of the inhibition of tumor cell growth through antioxidation, induction of tumor cell apoptosis, blockade of cell cycle, and enhancement of immunity by Se-containing polysaccharide were proposed. In the end, the potential application of Se-containing polysaccharide in the prevention and treatment of tumor was elucidated.
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Ecological explanations for successful invasion of exotic plants
Qiang WANG, Shikun JIN, Xiao RUAN
Front Biol Chin. 2009, 4 (3): 271-281.
https://doi.org/10.1007/s11515-009-0032-7
The intentional introduction of exotic species can increase the level of local biodiversity, enrich people’s material lives, and bring significant social and economic benefits that are also the symbols of human progress. However, along with the frequent intercourse among countries and regions, the frequency of uncontrolled cross-regional migration of species is increased and there is a lack of scientific management strategy for the intentional introduction of exotic species. Exotic species invasion, which is behind habitat fragmentation, has become the second largest threatening factor to the maintenance of the global-scale level of biological diversity. Exotic species invasion can destroy the structure of an ecosystem, disturb the economic life of a society, and do harm to human health. In this paper, the authors review some of the ecological explanations for issues such as “what causes or mechanisms have led to the successful invasion of exotic species”, including the “ideal weeds characteristics”, “biodiversity resistance hypothesis”, “enemies release hypothesis”, “evolution of increased competitive ability hypothesis”, “niche opportunity hypothesis”, and “novel weapon hypothesis”. The authors also analyze and evaluate the background and theoretical basis of the hypotheses, providing explanations for some phenomena, as well as the deficiencies of these explanations.
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Advances in research of induced resistance to insects in cotton
Xiaonan TI, Qunchi ZHANG
Front Biol Chin. 2009, 4 (3): 289-297.
https://doi.org/10.1007/s11515-009-0017-6
Any change in a plant that occurs following herbivory or environmental factors is an induced response. These changes include phytochemical induction, increases in physical defenses, emission of volatiles that attract predators and parasitoids of herbivores, and reduction in plant nutritional quality for herbivores, which is termed induced resistance. Induced resistance has been demonstrated ubiquitously in plants. It is one of our goals to review what is known about the induced resistance to herbivorous insects in cotton, including three resistance secondary metabolites (terpenoid, tannin, and flavonoids) that are contained at any significant levels of resistance to herbivorous insects in cotton cultivates. In many cases, the quantities or quality of secondary metabolites in plant are changed after attacked by insects. This review focuses on induced plant resistance as quantitative or qualitative enhancement of defense mechanism against insect pests, especially on the abiotic-elicitors-induced resistance in cotton plants. The abiotic-elicitor of cupric chloride, an exogenous inorganic compound, may induce the secondary metabolites accumulation and is referred to as a copper-inducible elicitor (CIE). Finally, we discuss how copper-inducible elicitor may be used in the Integrated Pest Management (IPM) system for cotton resistance control.
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Quantitative genetic estimates of growth-related traits in the common carp (Cyprinus carpio L.): A review
Chenghui WANG
Front Biol Chin. 2009, 4 (3): 298-304.
https://doi.org/10.1007/s11515-009-0031-8
The common carp (Cyrpinus carpio L.) is the oldest cultured and the most domesticated fish species, as well as one of the most important freshwater fishes in the world. However, scientific studies on evaluating the growth-related quantitative traits in this fish are limited. Heritability, the most important parameter in selective breeding programs, was extensively studied for the growth-related traits. The values varied widely among the experiments and methods used because of the existence of common environmental, dominance and maternal effects. However, correlations in phenotypic and genetic levels first evaluated several years ago were limited. On the other hand, heterosis was widely reported and easily obtained for growth-related traits in the common carp. Meanwhile, genotype environment interaction and prediction of breeding values have been studied recently, and are very important in conducting selective breeding programs. The developmental quantitative genetics of growth-related traits was first analyzed in the common carp for reasonable selection during ontogeny. It is expected that genetic improvement will be achieved by carrying out direct selective breeding in the common carp.
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Quantitative detection of Cymbidium mosaic virus by real time PCR
Aichun LIU, Yun ZHAO, Songlin RUAN, Guozheng SHEN
Front Biol Chin. 2009, 4 (3): 314-320.
https://doi.org/10.1007/s11515-009-0026-5
The technique of SYBR Green-based quantitative real-time reverse transcription polymerase chain reaction (real-time RT-PCR) was applied to quantitative detect a 764 bp nucleotide sequence containing total coat protein (cp) gene of Cymbidium mosaic virus (CyMV). The plasmid containing the target sequence was constructed to prepare the standard curve and detect the sensitivity. The standard curve was drawn based on the linear relationship between the logarithm (base 10) of the quantity of target sequence and cycle threshold [C(T)]. While the concentration of plasmid DNA falling within the range of 2.6×107 to 2.6×102 copies per tube established a regression equation, y=-0.3583x+10.32, and related coefficient: r2=0.995, The real-time RT-PCR assay for CyMV had a minimum detectable quantity of two copies per tube. The naturally infected samples of Phalaenopsis sp. and the artificially inoculated samples of Arachnis sp. with trace CyMV were quantitatively detected using this method. CyMV in the positive samples of Phalaenopsis sp. and Arachnis sp. was confirmed by DNA sequencing and cp gene homeology blast. The results showed that CyMV extracted from the leaves of orchid in Hangzhou, Zhejiang Province, China, could be derived from Kunming city (KM), Yunnan Province, China. This method characterized by high sensitivity, specificity, and precision is suitable for early diagnosis and quantitative detection of CyMV.
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Preparation, characterization, and antibacterial activity of oleic acid-grafted chitosan oligosaccharide nanoparticles
Lu HUANG, Xiaojie CHENG, Chengsheng LIU, Ke XING, Jing ZHANG, Gangzheng SUN, Xiaoyan LI, Xiguang CHEN
Front Biol Chin. 2009, 4 (3): 321-327.
https://doi.org/10.1007/s11515-009-0027-4
An oleic acid-grafted chitosan oligosaccharide (CSO-OA) with different degrees of amino substitution (DSs) was synthesized by the 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC)-mediated coupling reaction. Fourier transform infrared spectroscopy (FT-IR) suggested the formation of an amide linkage between amino groups of chitosan oligosaccharide and carboxyl groups of oleic acid. The critical aggregation concentrations (CACs) of CSO-OA with 6%, 11%, and 21% DSs were 0.056, 0.042, and 0.028 mg·mL-1, respectively. Nanoparticles prepared with the sonication method were characterized by means of transmission electron microscopy (TEM) and Zetasizer, and the antibacterial activity against Escherichia coli and Staphylococcus aureus was investigated. The results showed that the CSO-OA nanoparticles were in the range of 60-200 nm with satisfactory structural integrity. The particle size slightly decreased with the increase of DS of CSO-OA. The antibacterial trial showed that the nanoparticles had good antibacterial activity against E. coli and S. aureus.
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Season variability of iron effects on periodic culture of microalgae Dunaliella viridis Teod.
N. G. MENZYANOVA, A. V. GOLTVYANSKY, Y. A. KUZNETSOVA, E. I. SYSENKO
Front Biol Chin. 2009, 4 (3): 328-336.
https://doi.org/10.1007/s11515-009-0019-4
Effects of different iron concentrations (final concentrations of iron in Artari’s medium: 3.7, 37.0, 74.0, and 185.0 mmol?L-1) on growth rate and contents of protein, triacylglycerides, and β-carotene in Dunaliella viridis cells at cultivation in different months were investigated. It was shown that the dose-dependent effects of iron were notable for season variability. In the 1st experimental series (October, 2007), iron at researched concentrations did not affect growth rate of culture and protein, triacylglyceride, and β-carotene contents in cells. In experimental series conducted respectively in November 2007, December 2007, and February 2008, the dose-dependent stimulation of microalgae growth was observed. For each of these experimental series, there were particular dose dependences of protein, triacylglyceride, and β-carotene contents in microalgae cells at cultivation on media with iron at different concentrations. Meanwhile, for all of the four experimental series conducted in different months, variability of growth rate and analyzed parameters of microalgae Dunaliella viridis as control (cultivation without iron) was shown. It is suggested that these functional differences of control cultures of microalgae in different months caused variability in the dose-dependent effects of iron in a Dunaliella viridis culture. The possibility of iron usage for increasing microalgae biomass and for enriching it by β-carotene in Dunaliella viridis culture with initial low productivity and low β-carotene content is considered.
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ABA and GA3 affect the growth and pigment composition in Andrographis paniculata Wall.ex Nees., an important folk herb
M. GOMATHINAYAGAM, V. E. ANURADHA, Changxing ZHAO, Gloria A. AYOOLA, C. Abdul JALEEL, R. P. ANNEERSELVAM
Front Biol Chin. 2009, 4 (3): 337-341.
https://doi.org/10.1007/s11515-009-0018-5
In this study, 5 μmol?L-1 abscisic acid (ABA) and gibberellic acid (GA3) were used to study the effect of both growth regulators on the morphological parameters and pigment composition of Andrographis paniculata. The growth regulators were applied by means of foliar spray during morning hours. ABA treatment inhibited the growth of the stem and internodal length when compared with control, whereas GA3 treatment increased the plant height and internodal length. The total number of leaves per plant decreased in the ABA-treated plants, but GA3 treatment increased the total number of leaves when compared with the control. Both growth regulators (ABA and GA3) showed increased leaf area. ABA and GA3 treatments slightly decreased the total root growth at all the stages of growth. The growth regulator treatments increased the whole plant fresh and dry weight at all stages of growth. ABA enhanced the fresh and dry weight to a larger extent when compared with GA3. An increase in the total chlorophyll content was recorded in ABA and GA3 treatments. The chlorophyll-a, chlorophyll-b, and carotenoids were increased by ABA and GA3 treatments when compared with the control plants. The xanthophylls and anthocyanin content were increased with ABA and GA3 treatments in A. paniculata plants.
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Seed, cutting and air-layering reproductive inefficiency of noxious woody vine Merremia boisiana and its implications for management strategy
Mingguang LI, Haiyang LIU, Fenglan LI, Xiuyuan CHENG, Bin GUO, Zhiwei FAN
Front Biol Chin. 2009, 4 (3): 342-349.
https://doi.org/10.1007/s11515-009-0014-9
Merremia boisiana (Gagnep) van Ooststr. is a noxious fast growing woody vine and is able to grow overtop other plants, causing the death of plants underneath and forming monospecies stands. To formulate management responses, we assessed its seed and vegetative reproduction efficacy through indoor and field experiments. The number of flowers counted from bagged infructescences in Guangzhou ranged from 25 to 172, with an average of 80.80. Counting the seeds of bagged infructescences had shown that there were only 1.58 hard testa seeds in each infructescence. Seed vitality tests using red ink indicated that only 68.6% of hard testa and filled seeds were viable. The emergence rate of scarified hard testa seeds in the sand bed was 31.96%. Under imitated natural conditions, 8% of hard testa seeds could germinate, and 9% still retained their germination potential in one year. Thus, seedlings should be monitored and removed in a timely fashion after any attempt of clearing. Moving soil or transplanting plant from infested patches should be strictly prohibited at least for several years. All considered, an infructescence contributed 0.3 seedlings. The investigation in the field found no seedlings either inside or at the perimeter of the patch, suggesting scant expansion by means of seed dispersal. Therefore, the elimination effort could be focused on a relatively restricted scale of patches. Of 630 cuttings of young shoots, old shoots and old lying shoots with or without growth regulators, there were only four (or 0.63%) established individuals. Air-layering shoots all died in two months. Poor cuttings and air-layering reproduction indicated that regeneration from fragments of removed stems or accidentally dropped ones was quite unlikely, and thus mechanical removal was safe.
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Spatial variability of soil fertility factors in the Xiangcheng tobacco planting region, China
Haisheng CHEN, Zili SHEN, Guoshun LIU, Zhengxian TONG
Front Biol Chin. 2009, 4 (3): 350-357.
https://doi.org/10.1007/s11515-009-0021-x
It is essential to understand the spatial variability of soil properties in tobacco planting regions, so that the right decision can be made as to how many fertilizer rates are likely to be appropriated for the high-quality tobacco production. A total of 159 soil samples were taken from the surface soil (0-20 cm) in the Xiangcheng tobacco planting fields, Henan Province, in April 2002 to examine the concentration of soil organic matter, pH, available N, available P, and available K. The spatial variability was evaluated using geostatistics and geographic information system (GIS) analyses. The results show that among those five soil fertility factors, the variation coefficient of soil pH was the smallest, while that of available P was the greatest, which resulted from different cultivation methods and uneven fertilization. Analysis of the isotropic variogram indicated that the soil pH, organic matter, and available P semivariogram were well described with spherical models, with the distance of spatial dependence being 21020, 19150, and 8460 m, respectively, whereas the available N and available K semivariogram were well described with an exponential model, with the distance of spatial dependence being ranged from 7484 to 25320 m. Soil pH value was strongly spatially dependent with C0/sill being 0.1935, while the other four soil fertility factors were moderately spatially dependent with C0/sill ranging between 0.3528 to 0.5260. Through the Kriging analysis, the spatial distribution maps of soil properties were drawn using the arcview software. This study provides a scientific basis for field management, which targets soil quality improvement in the Xiangcheng tobacco planting region.
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Some ecological parameters of Artemia parthenogenetica Gahai and their use in resource exploitation
Qinxian JIA, Hongping WANG, Fanjing KONG, Mianping ZHEN
Front Biol Chin. 2009, 4 (3): 358-363.
https://doi.org/10.1007/s11515-009-0029-2
The effects of temperature on population characteristics of Artemia parthenogenetica Gahai from the Gahai Salt Lake, Qinghai Province, China, were studied in the laboratory at a salinity of 60‰. The major conclusions are as follows: (1) It was found that the adaptive temperature for the development of brine shrimp ranged from 10°C to 39°C. The threshold temperature of development (TD) and the effective accumulative temperature (TA) for hatching were 9.94°C·d and (22.91±2.08)°C·d, respectively. The TD and TA for the larva were 10.33°C·d and (261.26±24.1)°C·d, respectively, and for the whole generation were 10.28°C and (458.68±57.60)°C·d, respectively. (2) It showed that the population’s net reproduction rate (Ro), the intrinsic rate of natural increase (rm), the mean generation time (T), the finite rate of increase (λ), and the days for population to double (t) of the brine shrimp were determined over temperatures ranging from 19°C to 34°C by analyzing the life table and numerical model. In the temperature range of 14.3°C to 37.3°C for Ro>1, the optimum temperature (°C) for Ro, rm, λ, and t were 25.8°C, 29.8°C, 30.5°C, and 29.02°C, respectively. The maximum values of Ro, rm and λ were 54.86 ind., 0.106138/d, and 1.1070/d, respectively. The minimum value of t was 4.73 d. The value of T was in a range of 96.77 to 16.10 d. (3) Based on the 1993-1994 and 1997 data of the water temperature in the Gahai Salt Lake, Qinghai Province, it was estimated that the number of generation of A. parthenogenetica Gahai and the number of the reproductive peak value were 2.67±0.34 and 4.69±0.43 in a year, respectively. The peak of nauplii of the first generation was on April 20 to 28. The last whole generation began on August 10. The first reproductive peak was on June 18 to 25. The last reproductive peak was on September 12 to 17. The nauplii that hatched after September 1 cannot complete the development from nauplii to adults because of insufficient habitat effective accumulative temperature. During the period from July 11 to September 20, there was a relatively high productivity of the population. In this case, doubling the population would take less than 30 d, and the intrinsic rate of natural increase was over 0.02/d. Therefore, the value of resource exploitation would be maximal during that period annually.
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Do slope orientation and sampling location determine soil biota composition?
S. PEN-MOURATOV, N. BERG, N. GENZER, S. UKABI, D. SHARGIL, Y. STEINBERGER
Front Biol Chin. 2009, 4 (3): 364-375.
https://doi.org/10.1007/s11515-009-0023-8
“Evolution Canyon” is a typical Mediterranean-basin canyon with a summer dry stream at the bottom and large differences in vegetation cover and solar radiation between the north-facing slope (NFS) and the south-facing slope (SFS). It is known to act as an abiotic mediator influencing the community structure of soil fauna. The aim of this study was to determine the spatial dispersion of soil microbial and free-living nematode communities in the open sites (between shrubs) in the upper (0-10 cm) soil layer at four altitudes on both slopes. The combination of relative soil moisture availability and temperature, known to be one of the main triggers for soil biota activity, was explained by slope orientation. The above-mentioned differences were found to significantly affect microbial biomass and CO2 evolution resulting in temporary stress, corresponding to higher values in metabolic quotient (qCO2) values. These differences may represent microbial investment in energy in order to overcome stress resulting from the microclimatic differences between the two slopes. Moreover, the degree of substrate limitation (primary production due to the differences in plant cover) of microbial activity was explained by the difference in microbial functional groups. The total abundance of soil free-living nematodes was found to be 2-fold higher on the SFS than on the NFS. Thirty-nine genera, including 12 bacteria-feeders, 5 fungi-feeders, 12 plant-parasites, and 10 omnivore-predators, were found at the study site, with 34 genera on the NFS and 29 on the SFS. The generic diversity of the bacteria-feeding nematodes was higher on the SFS than on the NFS. This study elucidates the importance of slope orientation and its effect on the structural levels of soil microbial and nematode communities.
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