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1.
We determined: (a) the physiological consequences of overproduction of putrescine in transgenic poplar (Populus nigra x maximoviczii) cells expressing an ornithine decarboxylase transgene; and (b) effects of variation in nitrogen (N) concentration of the medium on cellular polyamine concentration in transgenic and non-transgenic cells. Cells grown in the presence of supplemental (to the normal concentrations of N sources in the growth medium) and reduced amounts of NH4NO3 and KNO3 were used to study effects on membrane permeability, mitochondrial respiratory activity, protein accumulation, growth rates and changes in cellular polyamine concentration. The N concentration of the MS medium was not a limiting factor for continued overproduction of putrescine in transgenic cells. However, continued supplies of NH4+ and NO3- were required to maintain homeostatic amounts of putrescine in both cell lines. The presence of high amounts of putrescine in transgenic cells had significant effects on the physiological parameters measured. Compared with non-transgenic cells, transgenic cells had greater plasma membrane permeability, less tolerance to NH4NO3, more tolerance to KNO3, and accumulated higher amounts of soluble protein. 相似文献
2.
To have a preliminary insight into biosafety of genetically transformed hybrid triploid poplars (Populus tomentosa × P. bolleana) × P. tomentosa with the cowpea trypsin inhibitor (CpTI) gene, two layers of rhizospheric soil (from 0 to 20 cm deep and from 20 to 40 cm deep, respectively) were collected for
microorganism culture, counting assay and PCR analysis to assess the potential impact of transgenic poplars on non-target
microorganism population and transgene dispersal. When the same soil layer of suspension stock solution was diluted at both
1:1 000 and 1:10 000 rates, there were no significant differences in bacterium colony numbers between the inoculation plates
of both transgenic and non-transgenic poplars. The uniform results were revealed for both soil layer suspension solutions
of identical poplars at both dilution rates except for non-transgenic poplars at 1:10000 dilution rates from the same type
of soil. No significant variation in morphology of both Gram-positive and Gram-negative bacteria was observed under the microscope.
The potential transgene dispersal from root exudates or fallen leaves to non-target microbes was repudiated by PCR analysis,
in which no CpTI gene specific DNA band was amplified for 15 sites of transgenic rhizospheric soil samples. It can be concluded that transgenic
poplar with the CpTI gene has no severe impact on rhizospheric microorganisms and is tentatively safe to surrounding soil micro-ecosystem.
[Supported by the National Project in Transgenic Plant and Application (Grant No. J2002-2003)] 相似文献
3.
To have a preliminary insight into biosafety of genetically transformed hybrid triploid poplars (Populus tomentosa × P. bolleana) × P. tomentosa with the cowpea trypsin inhibitor (CpTI) gene, two layers of rhizospheric soil (from 0 to 20 cm deep and from 20 to 40 cm deep, respectively) were collected for microorganism culture, counting assay and PCR analysis to assess the poten-tial impact of transgenic poplars on non-target microorganism population and transgene dispersal. When the same soil layer of suspension stock solution was diluted at both 1:1 000 and 1:10 000 rates, there were no significant differences in bacterium colony numbers between the inoculation plates of both transgenic and non-transgenic poplars. The uniform results were revealed for both soil layer suspension solutions of identical poplars at both dilution rates except for non-transgenic poplars at 1:10 000 dilution rates from the same type of soil. No significant variation in morphology of both Gram-positive and Gram-negative bacteria was observed under the microscope. The potential transgene dispersal from root exudates or fallen leaves to non-target microbes was repudiated by PCR analysis, in which no CpTI gene specific DNA band was amplified for 15 sites of transgenic rhizospheric soil samples. It can be concluded that transgenic poplar with the CpTI gene has no severe impact on rhizospheric microorganisms and is tentatively safe to surrounding soil micro-ecosystem. 相似文献
4.
Zhang Qian Lin Shanzhi Lin Yuanzhen Zhang Zhiyi Liu Haijun Zou Yening Wang Zeliang College of Biological Sciences Biotechnology Beijing Forestry University Beijing P. R. China College of Resources Environment Beijing Forestry University Beijing P. R. China 《中国林学(英文版)》2004,6(3)
The putative transgenic hybrid triploid poplars [(P. tomentosa P. bolleana) P. tomentosa] with CpTI gene have been outplanted in test field for 2 years. Although the authors previous studies have proved that they are highly resistant to 3 species of poplar-threatening insect pests and contain high content of CpTI protein in foliage, incorporation status of foreign CpTI gene in poplar genome is uncertain. In this present study, the incorporation of foreign CpTI gene in genome of 5 transgenic poplars was confirmed by PCR and Southern blotting analysis. DNA amplification showed that there were clear DNA bands of about 450bp specific to CpTI gene in transgenic lanes, while no corresponding band in non-transgenic lane was observed. Correspondingly, clear DNA hybridization signals and no signal were exhibited on film for DNA Southern blotting analysis in transgenic lanes and non-transgenic lane, respectively, which further confirmed the stable integration of foreign CpTI gene in genome of 2-year-old transgenic poplar. 相似文献
5.
Thomas W. McGinnis Jon E. Keeley Scott L. Stephens Gary B. Roller 《Forest Ecology and Management》2010
Typically, after large stand-replacing fires in mid-elevation Sierra Nevada forests, dense shrub fields occupy sites formerly occupied by mature conifers, until eventually conifers overtop and shade out shrubs. Attempting to reduce fuel loads and expedite forest regeneration in these areas, the USDA Forest Service often disrupts this cycle by the logging of fire-killed trees, replanting of conifers and killing of shrubs. We measured the effects of these treatments on live and dead fuel loads and alien species and modeled potential fire behavior and fire effects on regenerating forests. Sampling occurred in untreated, logged and herbicide-treated stands throughout the Sierra Nevada in four large fire areas 4–21 years after stand-replacing fires. Logging fire-killed trees significantly increased total available dead fuel loads in the short term but did not affect shrub cover, grass and forb cover, alien species cover or alien species richness. Despite the greater available dead fuel loads, fire behavior was not modeled to be different between logged and untreated stands, due to abundant shrub fuels in both logged and untreated stands. In contrast, the herbicide treatment directed at shrubs resulted in extremely low shrub cover, significantly greater alien species richness and significantly greater alien grass and forb cover. Grass and forb cover was strongly correlated with solar radiation on the ground, which may be the primary reason that grass and forb cover was higher in herbicide treated stands with low shrub and tree cover. Repeat burning exacerbated the alien grass problem in some stands. Although modeled surface fire flame lengths and rates of spread were found to be greater in stands dominated by shrubs, compared to low shrub cover conifer plantations, surface fire would still be intense enough to kill most trees, given their small size and low crown heights in the first two decades after planting. 相似文献
6.
增加林木的纤维素生产和转基因树的生长(英文) 总被引：6，自引：0，他引：6
纤维素是植物组成中的重要多聚物。纤维素也是重要的工业原料和可再生的能源物质。利用转基因技术可以降低林木中木质素含量并增加纤维素含量。木质素合成酶基因4-CL是一个重要的和木材再生有关的基因。在我们的研究中,将利用反义表达方法降低木质素含量,增加纤维素含量。研究包括:D4-CL基因的分离;转基因植物的生产;纤维素和木质素含量分析;中试。参69。 相似文献
7.
表达耐盐基因的转基因火炬松的再生 总被引：2，自引：0，他引：2
盐害是限制作物和树木分布和生产的重要因素。盐分过多导致细胞内水分缺失并影响许多重要的细胞代谢活动。本文利用火炬松作为模式植物建立了一套提高植物耐盐性的新技术。这一技术以火炬松合子胚为材料,利用农杆菌介导的转化方法将山犁醇脱氢酶和甘露醇脱氢酶基因转入火炬松。然后再生转化的愈伤组织和转基因植株。经DNA杂交证实的转基因植株被用于耐盐性试验,结果表明这些转基因的植株的耐盐性有明显的提高。这一技术对针叶树的遗传工程育种有重要的参考价值。图3表2参26。 相似文献
8.
The putative transgenic hybrid triploid poplars [(P. tomentosa × P. bolleana) × P. tomentosa] with CpTI gene have been outplanted in test field for 2 years. Although the authors’ previous studies have proved that they are highly resistant to 3 species of poplar-threatening insect pests and contain high content of CpTI protein in foliage, incorporation status of foreign CpTI gene in poplar genome is uncertain. In this present study, the incorporation of foreign CpTI gene in genome of 5 transgenic poplars was confirmed by PCR and Southern blotting analysis. DNA amplification showed that there were clear DNA bands of about 450bp specific to CpTI gene in transgenic lanes, while no corresponding band in non-transgenic lane was observed. Correspondingly, clear DNA hybridization signals and no signal were exhibited on film for DNA Southern blotting analysis in transgenic lanes and non-transgenic lane, respectively, which further confirmed the stable integration of foreign CpTI gene in genome of 2-year-old transgenic poplar. 相似文献
9.
Flower induction methods-hormone application or exposure to physiological stress, or both-are used routinely for shortening breeding cycles and increasing seed production in white spruce (Picea glauca (Moench) Voss). The objectives of this study were: (1) to evaluate the effects of flower induction on seed yield and quality in white spruce; and (2) to determine if flower induction treatments affect the maternal contribution to offspring. We assessed the effects of flower induction treatments, which consisted of gibberellin A(4/7) (GA(4/7)) and naphthaleneacetic acid (NAA) stem injections, on allele segregation for 28 clones, number of seeds per cone, number of sound seeds per cone, seed weight, and the germination rate of a subset of clones. Flower induction treatments did not affect any of the phenotypic traits examined. No increase in segregation distortion in allozyme loci following flower induction treatments was observed. 相似文献
10.
Five chemical and four non-chemical presowing treatments were tested on seeds of three conifers (Larix principis-rupprechtii Mayr, Pinus sylvestris L. var. mongolica Litv, and Pinus tabulaeformis Carr.). By itself, cold stratification with snow for 60 days did not significantly improve the germination percentage over that of soaking the seed in warm water (45 °C) for 12 hours. However, including either one or two dehydration-rehydration cycles after the cold stratification did improve both the percentage and speed of germination of seed from all three species. Soaking seed for 12 hours in various chemicals (KNO3, CaCl2, CuSO4, KMnO4 and GA3) before germination was less effective than the snow stratification followed by double dehydration-rehydration treatments (Chang and Lin, 1989). 相似文献
11.
12.
Tetsuya Igarashi Takashi Masaki Takuo Nagaike Hiroshi Tanaka 《Journal of Forest Research》2016,21(6):291-299
The possibility of restoring natural broadleaf forests may be decreased by the effects of plantation management, particularly in sites that undergo repeated rotation. We investigated the following two working hypotheses about the effects of repeated plantation of conifers on the natural regeneration of woody saplings in cool-temperate Japanese cedar plantations: (1) that repeated plantation of conifers decreases sapling species richness, and (2) that repeated plantation of conifers changes sapling species compositions. Our result supported the first hypothesis, because species richness was significantly lower in second-rotation plantations than in first-rotation plantations. The second hypothesis was not supported, because no significant or substantial differences in species composition were observed between plantations with different numbers of rotations. However, the abundance of tree (nonshrub) and gravity-dispersed species decreased after the second rotation of large saplings, albeit not those of small saplings, suggesting that response to repeated rotation depended on sapling size. Our results suggest that it is important to consider factors affecting the maintenance of a species in the plantations, such as distance from natural forests and seed sources, to minimize the effects of repeated plantation. 相似文献
13.
James W. Hanover 《New Forests》1992,6(1-4):159-178
Terpenoid substances in forest trees are versatile biochemical systems for use as genetic markers and for studying genetic regulation at the biochemical level. Univariate, multivariate and correlative data analyses from numerous studies on different coniferous species are presented. These data indicate that fitness values for most terpenes examined are probably so low as to be unmeasurable except in long evolutionary time spans. Variation patterns for monoterpenes often closely parallel racial differentiation for morphological traits and reflect the migratory history of species and species-complexes. Random drift and gene flow are likely the major influences on genetic organization of terpene variability. Mutation in regulatory genes may be responsible for quantitative variation within major gene systems for terpenes. The mono-, sesqui- and diterpene systems in conifers offer good opportunities for research on the nature of gene regulation in plants and its evolutionary significance. 相似文献
14.
Amines and their derivatives are known to influence insect behavior involved in feeding and reproduction. In order to examine
the feasibility of improving the resistance of poplar to insect pests by the introduction of a plant-derived amine-generating
transgene, explants from the hybrid poplar clone ‘INRA 717 1B4’ (P. tremula ×P. albo) were transformed with a Camptotheca acuminata tryptophan decarboxylase (TDC, EC 4.1.1.28) cDNA driven by the CaMV 35S promoter. The enzyme TDC catalyzes the decarboxylation
of tryptophan to tryptamine, which, in addition to being a bioactive amine itself, is known to act as a precursor of various
other indole derivatives. Putative transgenic lines were confirmed by PCR for the TDC1 gene sequence and by the expression analysis of the transgene mRNA and encoded protein. No visible phenotypic changes were
associated with ectopic TDC1 expression. Chemical and radiotracer analyses of the transgenic plants revealed tryptamine accumulation as high as 4 mM in
leaf tissue, and suggested that the tryptamine produced by ectopically expressed TDC was not further metabolized. Insect bioassays with the TDC transgenic plants showed that the tryptamine accumulation was consistently associated with adverse effects on feeding potential
and physiology of Malacosoma disstria (forest tent caterpillar). 相似文献
15.
Improvement in seed and seedling quality of Acacia auriculiformis after culling phenotypically inferior trees was studied
in a 6-year old seed production area (SPA). A 5-ha plantation was identified, of which 2.3 ha was converted into SPA. The
initial stocking, 1 612 trees·ha−1, was thinned down to 982 trees·ha−1 based on growth characteristics. The following fruiting season, seeds were collected from 10 randomly selected trees in culled
and non-culled stands, and seed physical characters, germination and seedling traits were assessed. Seed weight, seed thickness
and percentage germination increased by 32.1%, 4.43% and 22.37%, respectively in the culled stand compared to the non-culled
stand. Culling also increased the speed of germination, seedling dry weight and seedling vigor index. Heritability values
were high for seed weight (0.974) and seed thickness (0.948) while medium values were observed for percentage germination
(0.577) and total dry weight (0.534). Predicted genetic gain was 11.13% and 11.22% for seed weight and percentage germination,
respectively. The actual gain was 32.1, 51.9 and 22.9% for seed weight, percentage germination and total dry matter, respectively.
In conclusion, SPAs established by culling inferior trees could serve as sources of good quality seeds for reforestation programs
until genetically improved seeds are made available. 相似文献
16.
Khaya senegalensis is an increasingly important commercial plantation species in Australia, Sri Lanka and elsewhere. To address a problem of limited information on seed source variation from across its natural and planted range for key economic traits, two seed source trials were established in Sri Lanka in 2008. These included 3 Sri Lankan landrace and 21 natural stand sources from sub-Saharan Africa. Both trials were assessed for height and survival at age 2 years and then diameter at breast height, total height and stem form traits at age 6 years. Significant differences (P < 0.01) were found between seed sources for all traits at both sites. Significant differences were also found among seed sources in one trial for within seed source variability of tree volume and other traits, with two local Sri Lankan sources showing some of the highest variabilities. Whilst analyses of data pooled across the two sites revealed significant (P < 0.01) seed source by site interaction effects for most traits, such interactions will be of little practical significance for growth as correlations (r values) of seed source means across the two sites were moderate and positive, but for stem form traits correlations between the sites were low to very low and not significant. Options for future genetic improvement of the species in Sri Lanka are discussed. 相似文献
17.
We have extracted total DNA from different fractions of fresh wood as well as from cold-stored and air-dried wood harvested from transgenic aspen grown in the field. The highest amounts of DNA were obtained from bark/cambium tissue; the DNA quality, however, was poor. Best results in PCR and Southern blot analyses were obtained from DNA extracted from early wood. Using appropriate primer pairs, amplification products were obtained from both the foreign gene (transgene) and aspen genomic sequences. In Southern blot analyses transgene-specific hybridisation signals were obtained. This is the first report on the detection of foreign genes in wood sampled from genetically modified trees. 相似文献
18.
19.
生长素及其信号转导系统对植物的生长发育具有重要的影响。本研究从银腺杨'84K'(Populus alba × P. glandulosa cl. '84K')中分离了生长素受体基因PtrFBL1,利用PMDC32构建了PMDC32-PtrFBL1超量表达载体,并通过遗传转化获得了超量表达植株17个。对温室定植的3个转基因株系和对照植株的根系、生长量和光合指标等性状分析结果显示:转基因株系总根长和总根面积达到显著或极显著差异,而根系干质量、平均不定根系长度、平均不定根直径差异不显著;株高、平均节间长、地径和高径比皆高于对照,且大多数转基因株系达到显著差异;除气孔限制值(Ls)低于对照外,气孔导度(Cd)、水分利用效率(WUE)、光能利用效率(LUE)和叶绿素相对含量皆高于对照,且大多数转基因株系达到显著或极显著差异。以上结果表明,可能是FBL1超表达增加了转基因株系根系面积,提高了水分和养分的吸收利用,进而导致转基因株系光能吸收和转化效率提高,引起转基因株系生长加快。 相似文献
20.
通过对孟家岗林场40年生樟子松母树林不同密度疏伐处理后14个主要性状的统计分析,结果表明,疏伐处理对樟子松母树多个性状造成了显著影响,而且不同性状之间存在极为复杂的相关性;利用聚类分析和主分量分析法将存在显著差异性和相关性的8个性状分成3类,分别代表了生长、树冠和结实性状;通过这3类性状在各主成分上得分值的加权和比较表明,孟家岗林场40年生樟子松母树林疏伐抚育最佳密度是150株·hm-2。 相似文献