盐胁迫下Na^＋,K^＋,Cl^—对碱蓬和玉米离子的吸收效应

用ＮａＣｌ、ＫＣｌ、ＮａＮＯ３和ＫＮＯ３处理碱蓬（Ｓｕａｅｄａｓａｌｓａ）和玉米（Ｚｅａｍａｙｓ）幼苗,发现ＮａＣｌ胁迫引起Ｋ＋、Ｃａ２＋、Ｍｇ２＋、Ｆｅ２＋、Ｚｎ２＋、ＮＯ－３等必需元素的含量降低．认为ＫＣｌ和ＫＮＯ３处理引起碱蓬幼苗幼叶黄化的主要原因是Ｎａ＋的缺乏;ＫＣｌ处理引起玉米和碱蓬幼苗的干枯死亡主要是由于植物体内高浓度Ｃｌ－引起的;Ｎａ＋是引起盐生植物碱蓬叶片肉质化的重要因子;Ｃｌ－是刺激碱蓬生长的重要因子     

盐胁迫下不同浓度水杨酸对辣椒种子萌发及苗期生长的影响

采用不同浓度的水杨酸溶液处理盐胁迫(9g/L)下的辣椒种子,旨在研究水杨酸对盐胁迫下辣椒种子发芽和幼苗生长的影响.结果表明,在0.3 mmol/L的水杨酸和9g/L的NaCl处理下的辣椒种子的发芽势和发芽率较高,处理后的幼苗的根系活力、叶绿素含量也较高.认为低浓度的水杨酸溶液对盐胁迫下辣椒种子的萌发和幼苗的生长有促进作...     

木榄细胞膜Na~+/H~+逆向运输蛋白BgSOS1功能的初步验证

根据木榄BgSOS1的序列信息从木榄中克隆到了全长的BgSOS1基因,该片段包含1个3 462 bp的开放阅读框,可编码1 153个氨基酸的多肽.生物信息学的分析结果表明:该氨基酸序列所编码的蛋白与拟南芥、番茄、水稻、小麦、盐芥和杨树的SOS1蛋白高度同源,同源性分别为63.86%,66.61%,62.18%,60.19%,63.97%和75.97%;BgSOS1蛋白的N端含有12个跨膜的结构域,C端为1个较长的胞内结构域.尽管单个BgSOS1的表达并不能提高转基因酵母的抗盐性,但SOS1,SOS2和SOS3共表达的酵母,其抗盐性明显提高,这表明SOS2/SOS3蛋白激酶复合体可能通过调控BgSOS1的Na+/H+交换功能来提高木榄的抗盐机理.     

Effect of fatty acids on poly-amine contents and Na+/H+antiport activity in PM vesi-cles isolated from roots ofbarley under salt stress

With 200 mmol/L NaCI treatment on barleycultivar "Jian 4" (Hordeum vulgare L. cv. J4) seedlings for6 d, the contents of covalently and noncovalently conjugatedpolyamines (PAs) and activities of H+-ATPase in plasmamembrane (PM) vesicles isolated from the roots decreasedremarkably. Moreover, the activity of Na+/H+ antiport wasdetected first in PM vesicles. The results showed that thedecrease in the contents of membrane phospholipid, nonco-valently conjugated PAs and activity of H+-ATPase caused byNaCl could be restored partially by application of 1 mmol/Lstearic acid (C16:0) and linoleic acid (C18:2), and C18:2 wasmore effective than C16:0. In addition, a reduction in the con-tents of covalently conjugated PAs was only reversed par-tially in the presence of C18:2. Furthermore, Na+/H+ antiportactivity was strengthened by exogenous C16:0 and C18:2, andC18a was more effective than C16:0. The correlative analysissuggested that, after application of C16:0 and C18:2 under saltstress, there was a significant positive correlation existingamong phospholipid content, noncovalently conjugated PAlevels, H+-ATPase activities and Na+/H+ antiport activities,indicating that one of the mitigative mechanisms of exoge-nous fatty acids on salt injury was to improve membranephospholipid and PA contents, leading to an enhance inmembrane integrity and a change in charge status of PMvesicles, so the activity of membrane-associated enzymeH+-ATPase was increased and synthesis of Na+/H+ antiportprotein was activated.     

芦荟多糖对荷瘤小鼠肿瘤细胞钠泵的影响

报道了库拉索芦荟多糖、木立多糖对S1 80 小鼠肿瘤细胞膜Na+ ,K+ -ATPase的活性影响。结果表明 ,二者均能明显抑制荷瘤小鼠肿瘤细胞膜上Na+ ,K+ -ATPase的活性。芦荟多糖的这一作用改变了荷瘤小鼠细胞膜的物质、能量平衡 ,进而降低了肿瘤细胞的恶性程度。     

盐胁迫下土壤-杨树系统中离子运移与分布特征

在温室条件下,采用盆栽根箱培养的方法研究了盐胁迫下土壤-杨树系统中盐分离子的运移与分布特征。结果表明,各处理下杨树根际土壤中K^ 出现亏缺,Na^ 、Ca^ 、Mg^2 均出现富集。在低盐胁迫下,杨树根系优先选择吸收K^ 、Ca^2 和Mg^2 ,而对Na^ 的选择性有所减弱;两个杨树无性系能在根中积累较多的阳离子,同时I-69杨对Ca^2 ,NL-1381杨对K^ 、Ca^2 和Mg^2 向地上部分运输的选择性也有所增强,但抑制Na^ 向地上部分的运输,以减缓Na^ 对地上部分生长的胁迫。     

盐胁迫下外源硅调节金丝小枣根和叶片膜脂肪酸的研究

以2年生金丝小枣为试材,研究了NaCl胁迫下施硅(Si)与金丝小枣的根和叶片膜脂肪酸含量、组成及流动性的关系。结果表明:NaCl胁迫165 d,加硅与不加硅相比,金丝小枣根的饱和脂肪酸含量降低,不饱和脂肪酸含量升高,脂肪酸不饱和指数增大,膜流动性增强,碳链长度保持稳定;而在叶中则呈相反趋势。说明外源硅可调节盐(NaCl)胁迫下金丝小枣细胞膜脂肪酸含量、组成及流动性,该效应与金丝小枣器官的生理功能和生长特性有关。     

Impact of gamma radiation and salinity on growth and K+/Na+balance in two populations of Medicago sativa(L.)cultivar Gabès

The perennial Medicago sativa cv.Gabès is widely grown on saline soils in Tunisian oases.Morphological and physiological analyses of two populations(Mareth and Gannouch)were conducted in order to study the effect of salinity and gamma radiation(350 Gy)inter-action on two populations of this species.It has been shown that the two irradiated populations of Medicago sativa are fairly tolerant to salt at growth phase compared to the non-irradiated.Exposure to gamma irradiation(350 Gy),alone or in combination with salt stress,increased significantly (p<0.00 1)shoot number,stem height and chlorophyll b pigment especially for the Gannouch population,while no change occurred for the Mareth population.The presence of salt to 9 g/1 affected significantly the root biomass and induced a reduc-tion of shoot development of both control and irradiated alfalfa populations.For all treatments,plants of two populations remained able to produce and to allocate dry matter to the different organs.The survey of Na+/K+ratio showed that the growth of the aerial organs of two non-irradiated populations was at least determined by a selectivity in favour of the K+ions r2=0.97 and r2=0.59 for Mareth and Gannouch non-irradiated populations,respectively).However,the rather weak correlation detected for the irradiated populations,par-ticularly for the irradiated Gannouch.seems to be the consequence of the effect of irradiation that improved potassium availability.essential element for growth and development.Results also showed that the two irradiated populations,especially the Mareth,accumu-lated Na+ions in its photosynthetic organs.This accumulation was associated with an improvement of foliar water content at a level of salinity around 5 g/1.Such a mechanism reflects probably an inclusive behaviour of the plants and a good aptitude to use the dominant ions(Na+)for the osmotic adjustment.However,the non-irradiated populations are unable to adjust their internal osmotic potential.Consequently,irradiated plants have probably adapted to the osmotic stress by either closing their stomata or increasing the osmotic pressure of the leaf cells.     

NaCl胁迫下不同抗性野生大豆体内Na~+,K~+,Cl~-浓度比较分析

选取盐敏感型辉南野生大豆和耐盐型通榆野生大豆植物为材料,在5片复叶时期进行了10d的NaCl胁迫处理,测定了根、茎、叶中Na+,K+,Cl-的浓度,以探讨NaCl胁迫下野生大豆体内离子平衡的特点.结果表明:盐敏感型和耐盐型野生大豆植物在NaCl胁迫下,体内Na+和Cl-含量随胁迫浓度增加呈上升趋势,K+含量呈下降趋势.高盐胁迫下,除根部的K+外,其余各部位的Na+,K+,Cl-含量均表现为耐盐型野生大豆低于盐敏感型野生大豆.实验结果证明,通榆野生大豆具有颉颃盐逆境的生理特征和较好的适应性.     

碱胁迫对宁夏枸杞叶中Na＋，K＋，Ca2＋动态变化的影响

摘要：为探讨宁夏枸杞叶中离子平衡与盐碱胁迫的关系,研究不同浓度的NaHCO3溶液胁迫下,枸杞叶中Na^＋,K^＋,Ca^2＋的浓度变化,同时采用非损伤微测技术研究了枸杞叶中Na^＋,K^＋,Ca^2＋的流速变化．结果表明,在同一时间内（7,14,21d）,Na^＋的浓度随NaHCO。浓度的升高总体呈升高趋势,K^＋和Ca^2＋的浓度总体呈下降趋势,c（Na^＋）／c（Ca^2＋）随NaHCO3浓度的升高而升高;随着时间的变化,各个处理下枸杞叶中Na^＋的浓度总体呈现先降后升的趋势,K^＋的浓度总体呈现下降趋势,Ca^2＋的浓度总体呈现先升后降的趋势,c（Na^＋）／c（K^＋）总体呈现升高趋势,c（Na^2＋）／c（Ca^2＋）总体呈现先降后升的趋势;NaHCO。溶液胁迫7d时,诱导了枸杞叶肉细胞中净Na^＋,K^＋,Ca^2＋外排的增加．碱胁迫下造成c（Na^＋）／c（K^＋）和f（Na^＋）／c（Ca^2＋）升高的原因为,叶片中K^＋和Ca^2＋外排和Na^＋大量积累,这也是枸杞不耐碱的原因之一．可为种植枸杞改良盐碱地提供参考．     

NaCl胁迫下对刺槐叶片质膜H+~ATPase的影响

本文以二倍体刺槐和四倍体刺槐为试验材料，利用电子显微镜细胞化学方法对H+~ATPase进行定位，电镜下观察的黑色铅沉淀量与H+~ATPase的活性成正相关，结果表明：NaCl胁迫显著地提高了两种刺槐质膜的H+~ATPase活性，随着盐胁迫时间的延长，二倍体刺槐的质膜H+~ATPase活性呈现先上升再降低的趋势，而四倍体刺槐质膜H+~ATPase活性在整个实验过程中均呈现上升趋势，因此质膜H+~ATPase可能在四倍体刺槐的抗盐胁迫过程中起着重要作用。