RP-HPLC法测定长期盐胁迫下盐爪爪和盐穗木中的甜菜碱

通过对影响甜菜碱提取和测定的各种因素进行研究,建立了一种准确、快速的测定长期盐胁迫下盐爪爪和盐穗木中甜菜碱的HPLC方法。样品采用超声波甲醇提取,并依次通过强阴阳离子交换树脂(Dowex 50×8和Dowex 50×2)进行纯化,得到的样品采用反相C18柱进行分离,色谱条件:流动相为50 mmol/L、pH 4.5的KH2PO4溶液;波长200 nm下紫外测定,流速0.7 mL/min;此方法的检出限为0.02μg/mL,平均回收率为97.2%。通过对0~500 mmol/L NaCl胁迫下的盐爪爪和盐穗木中甜菜碱进行测定,甜菜碱的含量均呈现先增加后减少的趋势,盐爪爪在NaCl浓度为200 mmol/L时达到最大,而盐穗木在NaCl浓度为300 mmol/L时达到最大。     

Molecular Cloning and the Expression Pattern of a Phospholipid Hydroperoxide Glutathione Peroxidase in Kalidium foliatum under NaCl Treatment

Russian Journal of Plant Physiology - The halophyte Kalidium foliatum (Pall.) Moq. exhibits strong tolerance to salinity. Salt stress leads to reactive oxygen species (ROS) production, and high...     

盐分和水分胁迫对两种盐生植物盐爪爪和盐穗木种子萌发的影响

采用不同浓度NaCl和等渗PEG(分子量为6000)处理2种盐生植物种子(盐爪爪Kalidiumfoliatum、盐穗木Halostachys caspica)。结果表明,(1)NaCl和等渗PEG对种子的萌发均产生抑制作用,且PEG的抑制程度大于等渗NaCl,说明渗透胁迫是影响盐生植物种子萌发的主要因素;(2)盐胁迫和水分胁迫对盐生植物种子的萌发具有明显的抑制作用,降低了种子的萌发率,推迟了种子的初始萌发时间、延长了种子的萌发时间;(3)根据2种盐生植物种子萌发耐盐性比较,两种盐生植物均具有较强的耐盐性,在0~300 mmol.L-1NaCl盐溶液范围内,盐穗木种子相对萌发率达到95%以上,盐爪爪达到80%以上,说明盐穗木比盐爪爪具有更强的耐盐性。盐穗木种子耐盐适宜值为332.5 mmol.L-1,临界值为540 mmo.lL-1,极限值为749 mmo.lL-1;盐爪爪种子耐盐适宜值为246.5 mmol.L-1,临界值为391.8 mmo.lL-1,极限值为537 mmol.L-1;(4)低浓度的NaCl溶液对种子萌发的幼苗生长起着促进作用。在100 mmo.lL-1NaCl处理时,两种盐生植物幼苗的胚...     

Cd对蒌蒿生理生化及叶片超微结构的影响

采用Cd砂土污染试验,研究了Cd对蒌蒿生理生化特征及叶片超微结构的影响,结果表明在砂土Cd含量>180mg/kg,蒌蒿出现中毒症状,叶绿素含量、a/b值、POD含量均下降,MDA积累,膜质过氧化,叶绿体形状球形化、片层结构解体、双层膜边界模糊、嗜锇颗粒增多,细胞核形状凹陷,核质分布不均匀、染色质凝胶化。低于180mg/kg的砂土Cd浓度,蒌蒿的上述生理生化指标和叶片超微结构基本正常。蒌蒿可以耐受的Cd浓度不超过180mg/kg。     

盐爪爪耐盐相关基因的cDNA-AFLP分析

以不同浓度NaCl(0、100、200、300、400和500 mmol/L)处理生长了4周的盐爪爪(Kalidium foliatum),48h后取其幼嫩叶片用于RNA提取,并进行了cDNA-AFLP表达差异分析.结果表明,用256对引物扩增出连续性差异片段155条,按照NaCl浓度升高的顺序,划分为8种差异带类型,即强→弱"、弱→强"、有→无"、无→有"、有→无→有"、无→有→无"、强→弱→强"和弱→强→弱".测序后获得176个新表达序列标签(ESTs),已将长度大于100 bp的162个ESTs登录到GenBank,登录号为HO205290~HO205450.经BLAST序列比对分析发现,盐爪爪的耐盐性可能与能量、新陈代谢、防御、转运、转录和翻译等相关蛋白有关.     

Salinity and Temperature Effects on Germination for Three Salt-resistant Euhalophytes, Halostachys caspica, Kalidium foliatum and Halocnemum strobilaceum

The effects of three salinities (0, 100 and 500 mM NaCl) and four constant temperatures (10, 20, 30 and 35 °C) on seed germination of Halostachys caspica (M. B.) C. A. Mey., Kalidium foliatum (Pall.) Mop. and Halocnemum strobilaceum (Pall.) Bieb. were investigated. After seeds were treated with different concentrations of NaCl at constant temperatures of 10–35 °C for 16 days, ungerminated seeds were transferred to distilled water for 10 days to investigate the total germination; after this time, the ungerminated seeds from the 10 and 20 °C treatments were then moved to 35 °C for another 5 days to determine the final germination. The three plant species in the present experiment are salt-resistant euhalophytes growing in high saline soils in the Zhungur Basin in Xinjiang, a northwest province of China.Compared with germination under control conditions, germination percentages of all three species were not affected by 100 mM NaCl at 10–35 °C, while severely inhibited by 500 mM NaCl; germination percentages were very low at 10 °C up to 100 mM NaCl for all species; the optimum temperature for germination of H. caspica and K. foliatum was 20–30 °C, while 35 °C for H. strobilaceum, up to 100 mM NaCl; seeds did not suffer ion toxicity for all species, as evidenced by the high total germination after ungerminated seeds pretreated with 500 mM NaCl were transferred to distilled water at constant temperatures of 10–35 °C for 10 days, and the high final germination after the ungerminated seeds from the 10 and 20 °C treatments were subsequently moved to 35 °C for another 5 days; Halostachys caspica had greater sensitivity to increasing temperatures from 10 and 20 °C to 35 °C compared with the other two species.     

Hypersalinity effects on leaf ultrastructure and physiology in the mangrove Avicennia marina

The effects of hypersalinity on leaf ultrastructure and physiology in the mangrove, Avicennia marina, were investigated by comparing leaves of adult trees growing naturally in the field under seawater and hypersalinity conditions in Richards Bay, South Africa. We tested the hypothesis that hypersalinity has a deleterious effect on membranes and cellular organelles such as chloroplasts and mitochondria, which would impact negatively physiological processes, such as ion and water relations, and photosynthetic performance. Soil ψ and soil salinity were −2.96 ± 0.07 MPa and 35 ± 2.8 psu in the seawater salinity site, compared to −5.91 ± 0.42 MPa and 58 ± 3.6 psu respectively, in the hypersaline site. In the hypersaline site, leaves were smaller and thicker, with thicker cuticles, while chloroplasts, mitochondria and nuclei exhibited swelling and disintegration, compared to those at seawater salinity. Multivesicular structures and vesicles, observed in vacuoles, chloroplasts, mitochondria, and along cell walls and plasma membranes, were more abundant in leaves from the hypersaline than the seawater site, and were probably indicative of greater plant salt uptake in the former site. Leaf concentrations of total chlorophyll and chlorophylls a and b were lower in trees from the hypersaline site by 33%, 29%, and 45% respectively, compared to those at seawater salinity. Midday minimum xylem ψ was −3.82 ± 0.33 MPa in the seawater site and −6.47 ± 0.45 MPa in the hypersaline site. In the hypersaline site, the concentration of leaf Na⁺ was 40% higher, while those of K⁺, Ca²⁺, and Mg²⁺ were lower by 45%, 44%, and 54% respectively, than those in the seawater site. CO₂ exchange and the intrinsic photochemical efficiency of PS II were significantly lower in trees from the hypersaline site by 48 and 19% respectively. The ultrastructural evidence supported the physiological data that A. marina trees in the hypersaline site are under extreme salinity stress and that this species is growing there at the upper limit of its salt tolerance.     

辐射污染区盐爪爪根际可培养细菌群落组成及功能特性

【背景】我国西北某辐射污染区存在着丰富多样的耐辐射微生物资源,部分区域覆盖着耐盐植物盐爪爪,其根际存在明显的"离子岛"效应,开展其根际微生物相关研究对进一步挖掘污染区微生物资源及揭示盐爪爪的盐适应性和"离子岛"的形成具有重要的意义。【目的】分析辐射污染区盐爪爪根际微生物群落组成,挖掘潜在的微生物资源和功能特性。【方法】通过可培养方法,共选择了10种筛选培养基开展盐爪爪根际微生物的分离筛选,并对所获得的细菌进行了16S rRNA基因序列分子鉴定,进而进行相关菌株的抗逆特性、产酶特性和植物促生特性分析。【结果】分离获得的267株细菌归属于放线菌门(Actinobacteria)、变形杆菌门(Proteobacteria)、厚壁菌门(Firmicutes)等3个菌门中的20个属,发现潜在新种8个,其中放线菌门所含种属最丰富,说明盐爪爪根际存在着丰富的微生物多样性。相关抗逆性分析表明,分离得到的菌株70%以上可耐受10%NaCl,40%的菌株可耐受不同浓度的重金属胁迫。同时,研究获得了一批可产蛋白酶、脂肪酶、淀粉酶和纤维素酶的菌株以及植物促生菌株,可为相关酶制剂的筛选和微生物菌肥的研制提供丰富的材料。【结论】辐射污染区盐爪爪根际存在大量潜在的宝贵微生物资源,有待挖掘和开发。     

盐生植物盐爪爪甜菜碱醛脱氢酶基因的克隆及在盐胁迫下的BADH 基因的表达

根据已发表的几种藜科植物甜菜碱醛脱氢酶(BADH) 基因的同源保守区设计了一对引物, 采用RT-PCR 方法从盐生植物盐爪爪( Kalidium foliatum) 中扩增出BADH 基因的1 个开放阅读框架, 其核苷酸序列长1 503 bp , 推测的氨基酸序列全长为500 个氨基酸残基。核苷酸序列与藜科几种盐生植物如滨藜、碱蓬、菠菜、山菠菜和甜菜等的同源性为81% , 与甜土植物水稻的同源性为69%。氨基酸序列与以上两类植物(盐生植物和甜土植物) 的同源性比对为80% 和71% , 说明BADH 基因在藜科盐生植物中是一种较高保守的基因。BADH 基因编码的多肽在高等植物中行使重要的功能。用不同浓度的NaCl 胁迫处理盐爪爪植株, BADH mRNA 的表达水平比对照植株高, 说明盐爪爪BADH 基因的表达受盐诱导, 间接说明甜菜碱醛脱氢酶催化合成的甜菜碱作为渗透调节的小分子物质, 它的积累与盐胁迫存在紧密关联, 本研究为进一步从生理和分子水平阐明盐爪爪的耐盐机制提供一定的参考。     

盐爪爪根部微生物分布特征及盐浓度对碳源代谢分析的影响

【背景】耐盐植物盐爪爪广泛分布于盐碱荒漠区域,其根际存在明显的盐离子富集,形成"盐岛效应",研究此过程中微生物如何演替和适应,对揭示盐爪爪根际微生物的分布及其耐盐特性、"盐岛"的形成具有重要科学意义。【目的】揭示盐爪爪根际、根区及其周围环境土壤中微生物分布特征,确定不同盐浓度处理对根际微生物Biolog Eco微平板碳源代谢多样性的影响。【方法】采用Biolog Eco微平板技术,对采自新疆和硕地区的盐爪爪根际、根区和环境土壤微生物碳源利用情况进行分析,并采用不同浓度NaCl溶液对盐爪爪根际土壤样品进行稀释加样,评估盐浓度对根际微生物活性及多样性分析的影响。【结果】样品微生物代谢活性总体呈现根际根区环境的趋势;随着与根部距离的增加,样品中利用氨基酸、胺类碳源微生物所占比例明显降低,而利用吐温和肝糖等多聚化合物类碳源微生物所占比例明显增加;多样性分析表明,随着与根部距离的增加,Shannon指数(H)随之降低且存在明显差异。不同浓度NaCl溶液对采用BiologEco微平板技术分析盐爪爪根际微生物的代谢活性和代谢多样性有着明显的影响,其中采用5%NaCl溶液作为稀释加样液的根际微生物活性最高。【结论】盐爪爪根部微生物组成和分布有着明显的演变规律,且采用Biolog Eco微平板技术分析微生物代谢多样性时需进行培养条件的优化。     

盐爪爪Na^＋/H^＋逆向转运蛋白和焦磷酸酶的亚细胞定位

将盐爪爪Na+/H+逆向转运蛋白基因(KfNHX1)和焦磷酸酶基因(KfVP1)分别构建至植物表达载体,利用基因枪介导的方法转化洋葱表皮细胞,通过荧光显微镜观察研究其亚细胞定位.结果表明,转化了KfNHX1(或KfVP1)-GFP融合蛋白的洋葱表皮细胞仅膜系统散发荧光,而对照组即未转入KfNHX1(或KfVP1)基因的细胞则整体均匀发出荧光.说明KfNHX1和KfVP1可能定位于细胞的膜系统,作为跨膜转运蛋白在离子的调控运输中发挥重要作用.     

无叶假木贼和盐爪爪提取物的抗菌活性

无叶假木贼和盐爪爪地上部分乙醇提取物、不同溶剂萃取部分对供试病原细菌和真菌均表现出较好的抑制作用,其乙酸乙酯萃取部分和正丁醇萃取部分的抗菌活性明显强于石油醚萃取部分和水部分。结果表明,无叶假木贼中抗菌活性成分主要为极性中等的化合物,且很可能是具弱碱性、易与酸成盐的生物碱类。盐爪爪中抗菌活性成分同样为极性中等的化合物。     

盐生植物盐爪爪甜菜碱醛脱氢酶基因的克隆及在盐胁迫下的BADH基因的表达

根据已发表的几种藜科植物甜菜碱醛脱氢酶(BADH)基因的同源保守区设计了一对引物,采用RT-PCR方法从盐生植物盐爪爪(Kalidium foliatum)中扩增出BADH基因的1个开放阅读框架,其核苷酸序列长1503bp,推测的氨基酸序列全长为500个氨基酸残基。核苷酸序列与藜科几种盐生植物如滨藜、碱蓬、菠菜、山菠菜和甜菜等的同源性为81%,与甜土植物水稻的同源性为69%。氨基酸序列与以上两类植物(盐生植物和甜土植物)的同源性比对为80%和71%,说明BADH基因在藜科盐生植物中是一种较高保守的基因。BADH基因编码的多肽在高等植物中行使重要的功能。用不同浓度的NaCl胁迫处理盐爪爪植株,BADHmRNA的表达水平比对照植株高,说明盐爪爪BADH基因的表达受盐诱导,间接说明甜菜碱醛脱氢酶催化合成的甜菜碱作为渗透调节的小分子物质,它的积累与盐胁迫存在紧密关联,本研究为进一步从生理和分子水平阐明盐爪爪的耐盐机制提供一定的参考。     

Effects of NaCl salinity on 15N-nitrate fluxes and specific root length in the halophyte Plantago maritima L.

The effect of salinity on nitrate influx, efflux, nitrate net uptake rate and net nitrogen translocation to the shoot was assessed in a ¹⁵N steady state labelling experiment in the halophyte Plantago maritima L. raised for 14 days on solution supplied with 50, 100 and 200 mol m^–3 sodium chloride or without sodium chloride. Additionally, salinity induced changes in root morphology were determined. Specific root length increased upon exposure to elevated sodium chloride concentrations due to variations in biomass allocation and length growth of the tap root. Changes in root morphology, however, had a minor effect on nitrate fluxes when expressed on a root fresh weight basis. The decreased rate of nitrate net uptake in plants grown on elevated levels of sodium chloride was almost entirely due to a decrease in nitrate influx. Expressed as a proportion of influx, nitrate efflux remained unchanged and was even lower at the highest salinity level. At all sodium chloride concentrations applied the initial rate of nitrogen net translocation to the shoot decreased relative to the rate of nitrate net uptake. It is concluded that under steady state conditions the negative effect of sodium chloride on the rate of nitrate net uptake at non growth-limiting salinity levels was due to the interaction between sodium chloride and nitrate transporters in the root plasma membrane and/or processes mediating the translocation of nitrogen compounds, possibly nitrate, to the shoot.     

SNP和cPTIO对NaCl胁迫下拟南芥的生理影响

以拟南芥为材料,研究了0.5mmol/L的外源一氧化氮供体硝普纳(SNP)和200mmol/L的一氧化氮专一清除剂(cPTIO)对200mmol/LNaCl胁迫下对拟南芥的生理影响。0.5mmol/LSNP和200mmol/LcPTIO预处理2h后,加入200mmol/LNaCl。不同处理的拟南芥加入200mmol/LNaCl后,每隔12h取样一次,观察叶片生长情况、测定过氧化物酶(POD)、超氧化物歧化酶(SOD)、丙二醛(MDA)和超氧阴离子(O■)的变化。结果表明0.5mmol/L的SNP能缓解200mmol/LNaCl胁迫伤害,促进盐胁迫下幼苗的生长,显著提高抗氧化酶系统中POD和SOD活性,显著降低MDA和O■的含量,从而提高植株的抗盐性,而NO专一清除剂cPTIO能逆转SNP的上述效应。     

Response of antioxidant systems to NaCl stress in the halophyte Cakile maritima

The effects of salt stress on antioxidative activities were investigated in a coastal halophyte, Cakile maritima . Two Tunisian accessions, Jerba and Tabarka, were compared. Plants were subjected to 100, 200, or 400 m M NaCl for 20 days. Parameters of oxidative stress [malondialdehyde (MDA), electrolyte leakage (EL), and hydrogen peroxide (H₂O₂) concentration], activities of several enzymes [superoxide dismutase (SOD), catalase (CAT), peroxydase (POD), ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), and glutathione reductase (GR)], and antioxidant molecules (ascorbate, ASC, and glutathione, GSH) were determined. Growth of Jerba plants was improved at 100 m M NaCl as compared to that of control. Tabarka growth was inhibited by salt at all NaCl concentrations. The relative salt tolerance of Jerba was associated with high antioxidant enzyme activities and glutathione content, together with low MDA content, EL, and H₂O₂ concentration. Lower antioxidant activities and higher MDA content, EL, and H₂O₂ concentration were found in Tabarka. As a whole, these data suggest that the capacity to limit oxidative damage is important for salt tolerance of C. maritima .     

Effect of NaCl salinity in vivo and in vitro on ribonuclease activity in the halophyte Suaeda maritima

Ribonuclease (EC 2.7.7.17) activity in the obligate halophyte Suaeda maritima (L.) Dum. var. macrocarpa Moq. was studied in relation to salinity (increasing concentrations of NaCl) of incubation and growth media. In vitro, the addition of 50 to 400 m M NaCl did not affect ribonuclease activity. This result, which was also found for Phaseolus vulgaris , indicates that the hydrolase is insensitive to high saline concentrations. The subcellular distribution of RNase activity did not change significantly with the salinity of the medium or with the age of the plant. The microsomal ribonuclease activity expressed on a fresh weight basis represented in every case less than 6% of the total activity. After 23 days of culture, the absence of salt stimulated the activity of soluble ribonuclease in aerial parts of Suaeda ; inversely, the capacity of the enzyme was lower under optimal saline conditions (130 m M NaCl). This was also evidenced by transfer of whole plants from a non-saline to a saline medium. Such a saline shock caused a decrease followed by a stabilization of the capacity of ribonuclease from Suaeda . The influx of NaCl in the tissues lowered the activity of the hydrolase.     

Effect of NaCl and KCl salts on the growth and solute accumulation of the halophyte Atriplex nummularia

Atriplex nummularia plants are able to grow well in the absence of significant amounts of Na⁺. Medium levels of salinity (100 mM NaCl or KCl) did not cause substantial inhibition of growth but increasing concentrations of salt induced a progressive decline in length and weight of the plants. This inhibition was significantly higher in KCl grown plants than in NaCl grown plants. In addition, although it has been proposed that both K⁺ and Na⁺ are involved in the osmotic adjustment of plants in response to high soil salinity, we show that Na⁺ ions contribute more efficiently than K⁺ ions to perform this function. Our results also indicate that most of the osmotic adjustment of the plant was due to the accumulation of inorganic ions. The strong inhibition of Rb⁺ transport caused by internal sodium suggests that this cation could be efficiently used by the plant and, as a consequence, the transport of other monovalent cations is down-regulated.