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1.
水分胁迫下马铃薯SnRK2基因的表达模式与生理响应 总被引：1，自引：0，他引：1
以 “大西洋”和“陇薯3号”两个品种盆栽苗为试验材料,研究了水分胁迫下马铃薯（Solanum tuberosum）StSnRK2基因家族的表达特征及其与植株生理指标变化的相关性。结果表明：在发生严重水分胁迫时,“陇薯3号”和“大西洋”的抗氧化酶活性、MDA含量、相对电导率和脯氨酸含量均较对照显著提高,但增长幅度在品种间存在差异;StSnRK2基因家族的8个成员的相对表达量在“大西洋”和“陇薯3号”之间也存在明显差异,StSnRK2.1、StSnRK2.2和StSnRK2.3在两个品种中均表现为水分胁迫后相对表达量显著高于对照的趋势;StSnRK2.7的相对表达量与对照无显著差异,而StSnRK2.4在“陇薯3号”的相对表达量是对照的9.5倍,是8个基因成员在受水分胁迫后相对表达量最高的一个基因;StSnRK2.1、StSnRK2.2、StSnRK2.3、StSnRK2.4和StSnRK2.6的相对表达量均与部分生理指标呈极显著正相关,StSnRK2.5和StSnRK2.8两个基因的相对表达量与部分生理指标呈极显著负相关,StSnRK2.7基因的相对表达量与生理指标无显著相关性。 相似文献
2.
糖转运蛋白(SWEET)在植物生长发育和逆境胁迫响应中发挥着重要作用。本研究旨在克隆和分析羽毛针禾(Stipagrostis pennata)糖转运蛋白SpSWEET3基因的表达特征,为进一步探究其影响羽毛针禾根部沙套发育的机制及功能奠定基础。利用分子克隆技术克隆获得羽毛针禾SpSWEET3基因的全长开放读码框序列;利用生物信息学方法分析SpSWEET3基因的理化性质;利用qRT-PCR分析基因的表达特征;利用激光共聚焦显微镜观察分析其亚细胞定位。从羽毛针禾中克隆获得576 bp的SpSWEET3基因的全长开放阅读框,该基因编码一个含有191个氨基酸的碱性强疏水性蛋白,相对分子质量为21.619 kD。SpSWEET3属于PQ-loop超家族并含有典型的MtN3_slv结构域,发挥催化胞内糖外排的功能。亚细胞定位分析显示该基因定位于质膜,暗示其可能作为跨膜蛋白发挥功能。qRT-PCR结果显示SpSWEET3基因在羽毛针禾根组织中具有较高的累积表达,表明其对于沙套发育的重要作用;SpSWEET3基因的表达显著受到PEG干旱胁迫的诱导表达,表明其对于干旱适应的重要作用。蛋白质相互作用分析显示SpSWEET3可能通过与参与维持核酸结构稳定、转录因子、跨膜转运等蛋白质相互作用进而发挥转运糖的作用。本研究结果为深入研究SWEET基因的功能及其调控植物组织发育和适应逆境的机制奠定了基础。 相似文献
3.
铜离子对鳗池优势藻生长及种间竞争关系的影响 总被引：2，自引：0，他引：2
本研究以铜绿微囊藻(Microcystis aeruginosa)、水华微囊藻(Microcystis flos-aquae)、小球藻(Chlorella vulgaris)、四尾栅藻(Scendesmus quadricauda)4种鳗池常见优势藻为实验对象,研究不同铜浓度对4种藻生长、生理变化及种间竞争关系的影响.结果表明:铜绿微囊藻和水华微囊藻对铜比较敏感,40～640μg.L-1对微囊藻的抑制作用随铜浓度升高越来越显著,而该浓度范围的铜对于小球藻和四尾栅藻则具有不同程度的促进作用.在4种藻的竞争实验中,对照组中铜绿微囊藻和水华微囊藻占优势,40μg.L-1和640μg.L-1浓度中小球藻和四尾栅藻逐渐占优势,当浓度达到1 280μg.L-1时,4种藻均受抑制.SOD和MDA的检测结果显示,随着铜浓度的上升,4种藻的SOD酶活力先升后降,说明低浓度铜胁迫会导致抗氧化酶活性上升,活性氧清除能力加强,随着铜浓度的不断升高胁迫加剧,藻细胞内抗氧化酶系统的活性受到干扰,SOD活力开始下降,细胞膜过氧化作用增强,MDA含量逐渐升高. 相似文献
4.
以木兰围场国有林场管理局实施间伐后6种保留密度下（540、650、1 084、1 104、1 408和1 860 株 / hm2）油松人工林为研究对象,研究各土层的土壤有机碳和N、P、K等养分元素含量及其相关关系。研究结果显示：(1) 土壤有机碳含量和碳密度垂直递减特征明显,均随土壤深度的增加而显著减小,当林分密度由540 株 / hm2增加到1 860 株 / hm2时,土壤有机碳含量及碳密度变化规律不尽一致,其分布区间分别为10.56~21.21 g / kg,与5.48~11.70 kg / m2;(2) 林分密度对土壤有机碳及碳密度有显著的影响,1 408 株 / hm2油松林下土壤有机碳含量及碳密度分别与650 株 / hm2和1 860 株 / hm2油松林下土壤有机碳含量及碳密度呈显著性差异,而其它林分密度间无显著差异。当林分密度为1 104 株 / hm2时,各土层土壤全N和P、K的有效量及全量均保持在一个相对较高的水平,在0~60 cm深度土壤全N、全P、全K、有效P和速效K含量均值均达到最高,分别为1.38 g/kg、0.34 g/kg、32.75 g/kg、33.10 mg/kg和118.85 mg/kg;(3) 不同林分密度、不同土层土壤有机碳含量、碳密度与土壤全N及P、K的全量和有效量的相关显著性有差异,对整个土壤剖面而言,土壤有机碳含量及碳密度与土壤全N、全P、速效K均呈显著或极显著正相关;(4) 在本研究林分密度范围内,从林地土壤固碳的角度,建议将油松人工林的林分密度控制在1 104 株 / hm2。 相似文献
5.
病程相关蛋白（PR）广泛参与植物对生物和非生物胁迫的应答。采用cDNA末端快速克隆技术,从东方百合（Lilium）杂交品种索邦中克隆了PR1基因,并命名为LhSorPR1。LhSorPR1基因cDNA全长870 bp,5’非翻译区和3’非翻译区的长度分别为47 bp和274 bp。该基因的开放阅读框为549 bp,编码182个氨基酸。成熟的LhSorPR1蛋白（不含信号肽）分子量为18.19 kDa,等电点为5.69。采用同源建模方式构建的LhSorPR1蛋白三维结构与其模板番茄PR1蛋白p14a具有较高的相似性,说明百合PR1蛋白在结构和功能上与其他植物中的PR1蛋白具有较强的保守性。构建pCold Ⅱ-LhSorPR1原核表达,经IPTG诱导后,目的蛋白在大肠杆菌中以包涵体形式成功表达。使用免疫印迹方法对表达的LhSorPR1重组蛋白进行了验证,并对带有His标签的重组蛋白成功进行了纯化。 相似文献
6.
毛乌素沙地生物结皮层藓类植物培育试验研究 总被引：5，自引：1，他引：4
通过对毛乌素沙地不同发育程度的藓结皮进行养分分析,根据其N、P、K含量,对Knop培养液进行修正,按照正交试验设计方法进行室内培育实验,研究最适合毛乌素沙地藓类植株茎叶碎段生长发育的温度、培养液浓度以及培养液使用量。结果表明,当温度为15 ℃,培养液为low Knop,加液体量为12 ml时,藓结皮的生长发育状况良好,其株密度为329株·皿-1,平均株高为4.5 mm; 25 ℃时处理间差异不显著,生长情况不及15 ℃,而35 ℃高温下没有茎叶碎段生长繁殖。根据所有处理株高随时间的变化,得出了藓类植株生长拟合曲线。本实验可为野外培育藓结皮尤其是毛乌素沙地生物结皮的人工修复提供了一定的参考。 相似文献
7.
子午岭人工油松林群落更新特征及影响因子 总被引：2，自引：0，他引：2
采用样方法,对子午岭油松人工林群落更新特性以及环境因子对群落更新的影响进行研究,结果表明:油松人工林更新层有木本植物46种,其中有乔木16种,占总种数的33.33%,灌木29种,占总种数的64.58%。更新层的优势种有辽东栎、沙梾和鞘柄菝葜等,油松为更新层的次优势种,油松种群具有一定的自我更新能力;油松人工林群落更新层幼苗库丰富,高度级及龄级较小;更新方式以实生更新为主。林分密度对林下乔木幼苗、幼树数量影响极显著(P0.01),当林分密度从650株/hm2增加到1 550株/hm2时,林下更新的幼苗、幼树密度呈增加趋势,随着林分密度的继续增加,其密度逐渐减少;坡向对幼苗、幼树密度的影响显著(P0.05),当坡向由阳坡转向阴坡时,林下幼苗(树)密度逐渐增加;不同坡位林分更新特征各异,从坡下向上,幼苗密度逐渐减少,而幼树密度在中坡位最高,其次是下坡位,上坡位最低;随着海拔的升高,幼苗(幼树)密度逐渐减小。处于阴坡的中密度林分更新效果最佳,合理调整林分密度有利于油松人工林自然更新。 相似文献
8.
沙漠腹地乔木状沙拐枣对灌水量的生理生态响应 总被引：5，自引：3，他引：2
对不同灌水量条件下塔克拉玛干沙漠腹地乔木状沙拐枣（Calligonum arborescens Litv）的水分生理、生长和土壤水分进行了动态测定与分析。结果表明:①在35、24.5 kg·株-1·次-1和14 kg·株-1·次-1的灌水量下,土壤水分活跃层分别为:0～200、0～160 cm和0～100 cm。根系区土壤水分为3%～4%条件下,沙拐枣能正常生长,低于2.5%就会受到水分胁迫。②早晨和午后,沙拐枣的水势随着灌溉后时间的增加而降低,前期降幅较大。随着灌水量的减小,其水势降低较快,在14 kg·株-1·次-1处理下,灌溉3 d后早晨水势和午后水势分别达到-1.3 MPa和-2.19 MPa。③随着灌水量的减少沙拐枣的日耗水量急剧减小,液流速率也快速降低,灌溉后第15天,在24.5 kg·株-1·次-1和14 kg·株-1·次-1的灌水量下沙拐枣液流速率都为双峰型曲线,第25天3个处理都呈双峰型曲线。④不同灌水量下,沙拐枣的基径、新枝长度以及新枝直径的年增长量都随着灌水量的减少而减小,方差分析表明灌水量对新枝长度的影响非常显著(P=0.05)。 相似文献
9.
区域农业用地营养盐剩余量的长期变化研究 总被引：5，自引：4，他引：1
根据太湖南部长兴县农业统计资料,对该地区1949~2002年农业用地上N、P的剩余量作出评估。评估结果认为,1949~2002年期间,单位农业用地面积的N、P剩余量具有显著地增加趋势。20世纪50及60年代期间,N的剩余量增加缓慢,自70年代中期以后增加迅速。1996年达到历史最大值。1996年后,N剩余量呈现减少趋势。60年代初期以前,P处于亏损状态。1975~1980年期间,P剩余量呈现缓慢增长趋势,其后出现回落,自80年代中期以后出现迅速增加趋势。1992~1998年期间,P剩余量维持在35~45 kg/(hm2·a)之间的高水平变化,自1999年以后出现显著回落。 相似文献
10.
梁子湖水体P的季节变化与沉积物P释放初步研究 总被引：4，自引：0，他引：4
采用分级测定的方法对梁子湖沉积物中无机磷酸盐进行了分析,测定了梁子湖水体P的季节变化,并以室内模拟的方法研究梁子湖沉积物在pH值和温度控制下P的释放特征。研究表明,梁子湖水体P的含量呈明显的季节变化,冬季高,夏季低。沉积物无机磷(P i)中以钙磷(Ca—P)为主(55%~61%),铁磷(Fe—P)次之(28%~33%),铝磷(A l—P)最少(3%~5%)。在梁子湖的入水口和出水口,由于沉积环境影响到P的形态,P的释放明显较湖心高。在试验初期,由于扰动的影响,使得P的释放在第1天比第2天和第3天高,其后P的释放量则迅速增加。温度对P释放影响明显,其具体表现为,30℃时P释放达到峰值的时间比4℃时提前4 d,而且前者峰值比后者高出9倍。pH值对沉积物P释放同样有明显的影响,与正常状态下的湖水条件(pH值为8.5)相比,偏酸(pH值为5.5)和偏碱(pH值为11.5)条件下,P的释放量增加。 相似文献
11.
Lionel Camus Bjørn Gulliksen Michael H. Depledge Malcolm B. Jones 《Polar research》2005,24(1-2):111-118
Inevitably, aerobic life leads to the formation of deleterious reactive oxygen species (ROS) which participate in biomolecule oxidation, hence augmenting biomolecule turnover. Organisms have adapted to counteract the noxious effects of ROS by developing a battery of antioxidant defences (AOX) which comprise enzymes and low-molecular weight scavengers. Past studies have reported elevated AOX levels in polar pectinid bivalves compared with temperate congeners. This finding is controversial as mitochondrial ROS generation is low in polar versus temperate species, and, to date, there is no generally accepted explanation of the causes of increased basal AOX levels in polar waters. We suggest that the low food availability in those ecosystems may result in polar marine ectotherms diverting some energy into the maintenance of high AOX. We tested this hypothesis by comparing the total oxyradical scavenging capacity (peroxyl, hydroxyl and peroxynitrite) of three clam species: Laternula elliptica (Antarctic), Mya truncata (Arctic) and Mya arenaria (temperate). The data confirmed that polar bivalves are characterized by higher AOX. Herein, we propose that high AOX is required in environments characterized by low food availability as AOX efficiently protects biomolecules, notably the RNA expressed at high levels by cold-water ectotherms. Also, high AOX may explain the relatively long lifespan of most polar ectotherms. 相似文献
12.
The sympagic fauna (= ice fauna) of the Barents Sea was investigated on nine different cruises in 1982-1988. Each cruise lasted from two to five weeks. Sampling techniques were based on scuba diving. The abundant sympagic organisms were the polar cod ( Boreogadus saida ) and the three amphipods Apherusa glacialis, Onisimus sp. and Gammarus wilkitzkii .
Mean biomass-values (wet weight) of the invertebrate sympagic fauna ranged from 0 to 2 g/m2 . Values above 0.001 g/m2 were not recorded in five of the nine cruises. This is orders of magnitude lower than mean values recorded in multi-year ice north of Svalbard and in the Fram Strait where values between 1-10g/m2 are quite common.
Apherusa glacialis seemed to have the best spreading capacity of the three most conspicuous amphipods. Gammarus wilkitzkii was most dependent on a passive transport with the ice.
Sympagic amphipods play an important part in a food chain from microalgae to polar cod and marine birds in areas covered with ice, especially in areas with multi-year ice. 相似文献
Mean biomass-values (wet weight) of the invertebrate sympagic fauna ranged from 0 to 2 g/m
Apherusa glacialis seemed to have the best spreading capacity of the three most conspicuous amphipods. Gammarus wilkitzkii was most dependent on a passive transport with the ice.
Sympagic amphipods play an important part in a food chain from microalgae to polar cod and marine birds in areas covered with ice, especially in areas with multi-year ice. 相似文献
13.
Stage composition and vertical distribution of copepodids of Calanus finmarchicus and C. glacialis are described during spring and summer in Atlantic and Arctic waters, respectively. The two species co-occurred in the region of the Polar Front, both in moderate to high population densities. Ontogenetic migration, meaning that the migration range becomes progressively wider with advancing stage, was found in both species. The present study also revealed that C. finmarchicus had modifications in its ontogenetic vertical distribution. The standing crop of phytoplankton, predominantly Phaeocystis pouchetii , appeared to influence the degree of stage-specific segregation. Both low and high food concentrations tended to increase the vertical distribution of the instars. On the other hand, a narrow subsurface stratum of abundant phytoplankton led to an aggregation of copepodids at this depth. In the region of the Polar Front, where the two species co-occur, C. glacialis had a deeper distribution than C. finmarchicus , thus creating a bimodal vertical distribution pattern within the uppermost 200 m. 相似文献
14.
VTDAR BAKKEN 《Polar research》1990,8(1):55-59
The distribution of Brünnich's Guillemot in ice covered waters and near the marginal ice zone in the southern part of the Barents Sea was mapped from ship and helicopter in February/March 1987. High densities of Brünnich's Guillemot (up to 1,300 ind./km2 ) were found in ice leads. The density of birds was especially high over shallow banks where the sea depth was 40-80 m.
A diel movement was also recorded. In the evening the birds left the leads and flew south. Next morning they returned to feed in the open leads. How far they migrated is uncertain, but possibly they flew down to the open sea or to leads close to the marginal ice zone. The migration may have been a means of avoiding to become trapped if leads closed after dark. 相似文献
A diel movement was also recorded. In the evening the birds left the leads and flew south. Next morning they returned to feed in the open leads. How far they migrated is uncertain, but possibly they flew down to the open sea or to leads close to the marginal ice zone. The migration may have been a means of avoiding to become trapped if leads closed after dark. 相似文献
15.
Cinzia Verde Ennio Cocca Donatella de Pascale Elio Parisi Guido di Frisco 《Polar research》2004,23(1):3-10
The climatic features of Antarctic waters are more extreme and constant than in the Arctic. The Antarctic has been isolated and cold longer than the Arctic. The polar ichthyofaunas differ in age, endemism, taxonomy, zoogeographic distinctiveness and physiological tolerance to environmental parameters. The Arctic is the connection between the Antarctic and the temperate-tropical systems. Paradigmatic comparisons of the pathways of adaptive evolution of fish from both poles address the oxygen-transport system and the antifreezes of northern and southern species, (i) Haemoglobin evolution has included adaptations at the biochemical, physiological and molecular levels. Within the study of the molecular bases offish cold adaptation, and taking advantage of the information on haemoglobin amino acid sequence, we analysed the evolutionary history of the α and β globins of Antarctic, Arctic and temperate haemoglobins as a basis for reconstructing phylogenetic relationships. In the trees, the constant physico-chemical conditions of the Antarctic waters are matched by clear grouping of globin sequences, whereas the variability typical of the Arctic ecosystem corresponds to high sequence variation, reflected by scattered intermediate positions between the Antarctic and non-Antarctic clades. (ii) Antifreeze (glyco)proteins and peptides allow polar fish to survive at sub-zero temperatures. In Antarctic Notothenioidei the antifreeze gene evolved from a trypsinogen-like serine protease gene. In the Arctic polar cod the genome contains genes which encode nearly identical proteins, but have evolved from a different genomic locus–a case of convergent evolution. 相似文献
16.
ANNA JADWIGA KRZYSZOWSKA 《Polar research》1989,7(2):119-131
Studies were performed in Ny-Alesund, Spitsbergen, in June and July 1986 in order to gain an insight into the effect of activities of the polar research station on the nearby environment. It was found that chemical and mechanical factors were the most detrimental to the tundra environment. Fuel oil spills (110 m3 in 1986), which spread via surface and ground waters, were the most damaging of the chemical factors. Domestic sewage polluted the waters of Kolhamna Bay within an area of only 0.5 ha around its outlet in the sea. Vehicles and trampling caused mechanical damage inducing destruction of plant cover and changes in the ground structure; it modified ground moisture, bulk density and depth to the permafrost. The area degraded by human activity in the vicinity of the Ny-Alesund Research Station comprised 45 ha. The human impact around the polar station could be lessened by providing an alarm system to detect leaks and safety embankments around the oil tanks and pipelines, utilizing a settling tank for sewage, providing a simple incinerator for solid wastes, and instructing the inhabitants how to minimise impact on the environment. 相似文献
17.
东北地区植被分布全球气候变化区域响应 总被引：26，自引：8，他引：18
根据东北地区生态气候环境和生物地理规律对Holdridge生命地带分类系统进行修正,将东北地区植被分为寒温带湿润森林、寒温带潮湿森林、温带湿润森林、暖温带湿润森林、温带半湿润森林草甸草原、温带半湿润草甸草原、温带半干旱典型草原、暖温带半湿润草甸草原和暖温带半干旱典型草原等9 个生命地带并分析了其空间分布特征。运用大气环流模式分析东北地区由于温室气体增加导致的气候变化趋势。以此为基础评价东北地区植被分布的区域响应。全球气候变暖情景下,东北地区暖温带和温带范围明显扩大,而寒温带范围缩小甚至退出东北地区,植被分布界限显著北移;同时湿润区面积减少半湿润区和半干旱区扩大,导致森林面积缩小草原面积扩大。 相似文献
18.
In the field of phylogenetic analyses, the rbcL gene encoded large subunit Ribulose-1,5-biphosphate carboxylase/oxygenase (Rubisco, EC4.1.1.39), which plays a crucial role in the process of photosynthesis for most terrestrial plants, has been considered to be conserved; however, recent controversy regarding rbcL conservation has appeared since it was proposed to be under natural selection within all principal lineages of land plants. In this study, by examining the variation of DNA and protein sequences among 17 species in the family Tamaricaceae, three nonsynonymous mutations were identified to be under positive selection. The favored sites were located in the alph-helix domains of Rubisco, with decreased hydrophobicity and increased entropy, which could facilitate CO2 penetration into the active site of Rubisco. We also found that the expression level of rbcL in different genotypes of Reaumuria soongarica shifted in response to various stresses such as drought, temperature, salt, and light. This study not only sheds light on the functional/structural features of Rubisco in the evolution scenarios from C3-like into C4 in Tamaricaceae but also provides useful information on directing genetic performance to enhance photosynthesis efficiency of desert plants for sustaining fragile desert ecosystems; furthermore, it promotes the ability to cope with desert aridification and global warming. 相似文献
19.
Food samples from 102 seabirds from eight species (fulmar Fulmarus glacialis , common eider Somateria mollissima , glaucous gull Larus hyperboreus , kittiwake Rissa tridaayla , arctic tern Sterna paradisaea , Briinnich's guillemot Uria lorn via , black guillemot Cepphus grylle , little auk Alle alle) were collected during the period August 1991–1993 in the southern part of the Frans Josef Land archipelago, 80°N, 53°E. The pelagic amphipod Parathemisto libellula and polar cod Boreogadus saida were the two most commonly taken food items (frequency of occurrence over 50% and weight contribution more than 70%). Ice-associated crustaceans contributed to some 10% of the weight in the samples. In general, the food composition was very similar to that reported from Svalbard. However, birds from Frans Josef Land fed on a lower diversity of prey compared to Svalbard populations. 相似文献
20.
Extracellular enzymatic activities of cold-adapted bacteria from polar oceans and effect of temperature and salinity on cell growth 
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下载免费PDF全文 The potential of 324 bacteria isolated from different habitats in polar oceans to produce a variety of extracellular enzymatic activities at low temperature was investigated. By plate assay, lipase, protease, amylase, gelatinase, agarase, chitinase or cellulase were detected. Lipases were generally present by bacteria living in polar oceans. Protease-producing bacteria held the second highest proportion in culturable isolates. Strains producing amylase kept a relative stable proportion of around 30% in different polar marine habitats. All 50 Arctic sea-ice bacteria producing proteases were cold-adapted strains, however, only 20% were psychrophilic. 98% of them could grow at 3% NaCl, and 56% could grow without NaCl. On the other hand, 98% of these sea-ice bacteria produced extracellular proteases with optimum temperature at or higher than 35℃, well above the upper temperature limit of cell growth. Extracellular enzymes including amylase, agarase, cellulase and lipase released by bacteria from seawater or sediment in polar oceans, most expressed maximum activities between 25 and 35℃. Among extracellular enzymes released by bacterial strain BSw20308, protease expressed maximum activity at 40℃, higher than 35℃ of polysaccharide hydrolases and 25℃ of lipase. 相似文献